CSLB General Building (B) — All Questions

On a wood structural panel span-rating stamp such as 24/16, what does the second number (16) represent?

• a.The maximum roof rafter spacing the panel may bridge
• b.The maximum floor-joist spacing (inches) over which the panel may serve as subfloor✓
• c.The panel thickness in sixteenths of an inch
• d.The minimum nail spacing at panel edges

On a span-rated panel the two numbers are roof-support spacing / floor-support spacing. The 16 means the panel is rated as subfloor over joists up to 16 inches on center. The 24 is the roof rafter spacing, not the second number. Thickness is stamped separately, and edge nailing is set by the fastening schedule.2025 CA Residential Code §R503.2.1

When wood structural panel subfloor or sheathing is installed, what approximate gap is customarily left at panel edges and ends for expansion?

• a.No gap; panels must be tightly butted
• b.3/4 inch
• c.1/8 inch✓
• d.1/2 inch

Manufacturers and code commentary call for roughly a 1/8-inch gap at panel edges and ends so moisture swelling does not cause buckling. Butting tight invites buckling; 1/2 and 3/4 inch are far larger than needed and would leave unsupported spans and telegraph through finishes.2025 CA Residential Code §R503.2.1

For maximum stiffness, how should the long dimension (face grain) of wood structural floor panels normally be oriented relative to the supports?

• a.Perpendicular to (across) the joists, with end joints staggered✓
• b.Parallel to the joists
• c.At 45 degrees to the joists
• d.Direction does not matter for rated panels

Panels are strongest across their length, so the long dimension is laid perpendicular to the joists with end joints staggered so no continuous seam forms. Running the length parallel wastes the strong axis; a 45-degree layout is not a recognized method; and orientation matters even for rated panels.2025 CA Residential Code §R503.2.1

On a roof deck of wood structural panels installed without tongue-and-groove edges or solid blocking, what device is commonly used along unsupported panel edges to keep adjacent panels flush?

• a.Hurricane ties
• b.Framing clips
• c.Draft stops
• d.Panel edge (H) clips✓

Panel edge clips (H-clips) are set between rafters at unsupported panel edges to align adjacent panels and share load, allowing a thinner panel for a given span. Hurricane ties resist uplift at bearings, framing clips connect members, and draft stops subdivide concealed spaces; none align roof panel edges.2025 CA Residential Code §R803.2.3

When nailing wall sheathing, what is the BEST reason to follow the specified closer edge-nail spacing (for example 6 inches) rather than a wider spacing?

• a.It reduces the number of studs required
• b.It transfers shear and prevents panel edges from buckling or pulling loose under lateral load✓
• c.It eliminates the need for a water-resistive barrier
• d.It allows thinner sheathing everywhere

Edge nailing develops a wall's shear capacity; closer edge spacing keeps panel edges tight to the framing and transfers lateral (wind/seismic) load without buckling or nail pull-through. It does not change stud count, replace the WRB, or by itself permit thinner sheathing.2025 CA Residential Code §R602.3

For wood structural panel sheathing, how far should nails typically penetrate into the framing member to be effective?

• a.Just past the panel face
• b.Exactly the panel thickness
• c.At least about 1 inch into the framing✓
• d.The full length of the stud

Fastening schedules expect roughly 1 inch or more of penetration into the supporting framing so the nail develops withdrawal and shear resistance. Barely reaching the framing or matching only the panel thickness leaves too little embedment; penetrating the full stud is neither possible nor required.2025 CA Residential Code §R602.3

A glued-and-nailed subfloor squeaks after installation. Which construction detail MOST directly reduces the squeaks?

• a.Applying continuous construction adhesive on joists before setting panels and fastening while the adhesive is wet✓
• b.Increasing panel-edge gaps to 1/2 inch
• c.Using shorter nails than specified
• d.Leaving tongue-and-groove joints loose

A glued-and-nailed floor bonds the panel to the joist so the two act together and do not rub, the main cure for squeaks; adhesive must be continuous and fastened before it skins over. Oversized gaps, shorter nails, and loose T&G joints all increase movement and noise.

Which panel-joint practice BEST avoids a continuous weak line across a subfloor or roof deck?

• a.Aligning all end joints on the same joist
• b.Gluing every joint solid so panels cannot move
• c.Using only full sheets with no cut pieces
• d.Staggering panel end joints so they fall on different supports in adjacent rows✓

Staggering end joints (a brick-like pattern) keeps adjacent rows from sharing one continuous seam, distributing load and stiffness. Aligning all joints creates a hinge line; gluing does not address the seam pattern; and using only full sheets is neither practical nor the governing principle.2025 CA Residential Code §R503.1

Beyond structure, why is careful sealing of subfloor and sheathing joints emphasized in current California construction?

• a.It increases the panel span rating
• b.It limits air leakage, supporting the Energy Code's building-envelope tightness goals✓
• c.It replaces the need for wall insulation
• d.It allows nails to be spaced farther apart

Sealed sheathing joints reduce uncontrolled air leakage through the envelope, supporting the Energy Code's air-tightness objectives and comfort/efficiency. Sealing does not change span ratings, replace insulation, or permit wider nail spacing, which is set by the structural fastening schedule.2025 CA Energy Code

Where wood structural panels serve as combination subfloor-underlayment to receive resilient flooring directly, which panel characteristic is MOST important?

• a.Maximum knot size
• b.Darkest face veneer
• c.A touch-sanded face and a rating for combination subfloor-underlayment✓
• d.The heaviest available panel

Panels used as subfloor-underlayment for thin resilient flooring must be specifically rated for that use and have a smooth (touch-sanded) face so joints and grain do not telegraph. Knot size, veneer color, and sheer weight are not the controlling factors for a finish-ready underlayment surface.2025 CA Residential Code §R503.2.4

In a framed wall opening, what is the PRIMARY structural role of the header?

• a.To provide a nailing surface for drywall only
• b.To seal the opening against air leakage
• c.To carry loads from above across the opening to the studs on each side✓
• d.To hold the window frame square

A header is a beam that spans the opening and transfers the roof, ceiling, or floor loads above it down to the jack (trimmer) studs on each side and into the foundation. Drywall nailing, air sealing, and squaring the window are secondary or unrelated functions.2025 CA Residential Code §R602.7

In header framing, what is the difference between a king stud and a jack (trimmer) stud?

• a.The king stud runs full height beside the opening; the jack stud is cut to support the header end✓
• b.The king stud supports the header; the jack stud runs full height
• c.Both run full height and neither supports the header
• d.The jack stud is always doubled and the king stud is never used

The king stud extends full height from plate to plate alongside the opening and is nailed to the header for lateral stability, while the jack (trimmer) stud is shorter, nailed to the king stud, and directly supports the underside of the header end. The other statements reverse or confuse these roles.2025 CA Residential Code §R602.7

As a header spans a wider opening and carries more load, how does the required number of jack (trimmer) studs at each end typically change?

• a.It decreases because the header gets stiffer
• b.It increases so the added bearing area can carry the greater end reaction✓
• c.It stays at one regardless of span
• d.Jack studs are removed and replaced by the king stud only

Wider spans and heavier loads raise the reaction delivered to each header end, so codes and manufacturer tables call for additional jack studs to provide enough bearing area beneath the header. The number does not decrease with span, is not fixed at one, and a king stud cannot substitute for bearing jacks.2025 CA Residential Code §R602.7

What is a cripple stud in wall framing?

• a.A stud that has been notched more than 40 percent
• b.The full-height stud at a corner
• c.A short stud above a header or below a sill that continues the stud pattern✓
• d.A stud rotated 90 degrees for a partition intersection

A cripple stud is a shortened stud that fills the space above a header (or below a window sill), continuing the regular stud spacing so sheathing and top/bottom framing stay supported. It is defined by length and location, not by notching, corner position, or rotation.2025 CA Residential Code §R602.7.4

A framer builds exterior corners using a three-stud arrangement that leaves room for insulation and provides drywall backing. What is the MAIN advantage of this over a solid stud-packed corner?

• a.It uses more lumber
• b.It eliminates the need for corner sheathing
• c.It makes the corner load-bearing where a solid corner is not
• d.It allows insulation into the corner cavity, reducing thermal bridging, while still backing the interior finish✓

An insulated (California/three-stud) corner leaves a cavity that can be insulated, cutting the thermal bridge a solid lumber-packed corner creates, and still provides a nailing surface for interior drywall. It uses less lumber, does not remove sheathing, and both corner types can be load-bearing.2025 CA Energy Code

In an EXTERIOR bearing wall, what is the MAXIMUM depth a stud may be NOTCHED, expressed as a fraction of its depth?

• a.10 percent
• b.25 percent✓
• c.40 percent
• d.60 percent

In an exterior or bearing wall, a stud may be notched to a maximum of 25 percent of its depth. Forty percent is the notch limit for non-bearing partitions, 60 percent is a bored-hole limit for non-bearing studs, and 10 percent is more restrictive than the code requires.2025 CA Residential Code §R602.6

For a bored hole in an EXTERIOR bearing-wall stud, what is the MAXIMUM hole diameter as a fraction of the stud depth, and how close may it come to the stud edge?

• a.25 percent, 1/4 inch from the edge
• b.60 percent, no edge limit
• c.40 percent, with at least 5/8 inch of wood between the hole edge and the stud edge✓
• d.50 percent, flush with the edge

A bored hole in a bearing-wall stud may be up to 40 percent of the stud depth and must leave at least 5/8 inch of solid wood between the hole and the edge of the stud. The 25 percent figure is the notch limit, 60 percent applies to non-bearing studs, and holes may never be flush with the edge.2025 CA Residential Code §R602.6

When a pipe notch or bore in a wood stud leaves less than 1-1/4 inch of wood between the pipe and the exposed face, what protection does the code require?

• a.A steel plate or shield of adequate thickness over the area to guard against fastener penetration✓
• b.Nothing, provided the pipe is copper
• c.Doubling the drywall thickness
• d.Filling the notch with expanding foam

Where less than 1-1/4 inch of wood remains between a pipe and the stud face, a steel nail plate (typically at least 16 gauge) must protect the pipe so later nails or screws cannot puncture it. Pipe material, extra drywall, and foam do not stop a driven fastener from reaching the pipe.2025 CA Residential Code §R602.6.1

Where the two members of a double top plate are spliced (end joints), how must the joints in the upper and lower plates be arranged?

• a.Directly over each other for a tight fit
• b.Both centered over the same stud
• c.Within 6 inches of each other
• d.Offset by at least 24 inches so the joints do not line up✓

Double top-plate splices must be offset at least 24 inches so the two joints never coincide, keeping the plate continuous for load transfer and tension across the wall. Stacking the joints, centering both on one stud, or spacing them only 6 inches apart would create a weak, hinged line.2025 CA Residential Code §R602.3.2

Fireblocking is required in concealed wall spaces primarily to accomplish what?

• a.Add structural shear strength to the wall
• b.Provide a nailing surface for siding
• c.Cut off concealed draft openings and slow the spread of fire and hot gases through hidden spaces✓
• d.Support plumbing pipes

Fireblocking closes concealed vertical and horizontal openings (such as at floor and ceiling levels and around soffits) so fire and hot gases cannot travel unchecked through the framing cavities. It is not intended for shear strength, siding attachment, or supporting pipes.2025 CA Residential Code §R602.8

Which material is generally ACCEPTABLE as fireblocking in a concealed stud space?

• a.Loose sawdust
• b.Nominal 2-inch lumber fitted to the opening✓
• c.A sheet of ordinary polyethylene film
• d.Uncased fiberglass batts hung loosely in the cavity

Approved fireblocking includes 2-inch nominal lumber cut to fit, two thicknesses of 1-inch lumber, wood structural panels, gypsum board, and certain mineral or approved materials. Loose sawdust and thin polyethylene are combustible or ineffective, and unsupported batts alone are not accepted general fireblocking except where specifically permitted.2025 CA Residential Code §R602.8

In a braced wall line, what does the term 'braced wall panel' refer to?

• a.A specific length of wall, sheathed and fastened as prescribed, that resists lateral (wind/seismic) loads✓
• b.Any interior partition that divides two rooms
• c.The drywall finish applied to the room side of a wall
• d.A prefabricated window header assembly

A braced wall panel is a defined, code-compliant segment of a braced wall line, built and fastened by an approved bracing method, that provides the wall's resistance to wind and earthquake forces. It is not simply any partition, the drywall finish, or a header assembly.2025 CA Residential Code §R602.10

In conventional roof framing, where should rafter ties (which resist the outward thrust of rafters) generally be located?

• a.At the ridge
• b.Halfway up the rafter length
• c.In the lower third of the attic (rafter) height, near the top-plate level✓
• d.Anywhere, as long as they are nailed to the rafters

Rafter ties resist the outward spreading thrust rafters exert on the walls and are most effective near the bottom of the rafters, in the lower third of the attic height. Placing them at the ridge (collar-tie zone) or midheight greatly reduces their ability to hold the walls in; location is not arbitrary.2025 CA Residential Code §R802.4

What is the practical difference between a collar tie and a rafter tie in a gable roof?

• a.They are identical terms
• b.A collar tie is placed in the upper third to resist ridge separation/uplift, while a rafter tie near the plate resists outward wall thrust✓
• c.A collar tie carries the floor load; a rafter tie carries the ridge
• d.Both must be steel

A collar tie sits in the upper third of the roof and mainly keeps the rafters from separating at the ridge under wind uplift, while a rafter tie sits low, near the wall plates, and resists the outward horizontal thrust that would push the walls apart. They are not identical, do not carry floor load, and need not be steel.2025 CA Residential Code §R802.4

When rafters frame to a non-structural ridge board (not a ridge beam), what is the minimum requirement for that ridge board's depth?

• a.Not less than the cut end (plumb-cut depth) of the rafter✓
• b.Exactly 2 inches regardless of rafter size
• c.Twice the rafter depth
• d.Half the rafter depth

A ridge board must be at least as deep as the cut (plumb) end of the rafters bearing against it so the full rafter end seats against the board. A fixed 2 inches, twice, or half the rafter depth would either under- or over-size the board relative to the rafter end it must fully support.2025 CA Residential Code §R802.3

Why does a structural RIDGE BEAM allow a roof to be built without rafter ties, whereas a simple ridge BOARD does not?

• a.The ridge beam is lighter
• b.The ridge board is stronger than a beam
• c.Ridge boards are only used on flat roofs
• d.A ridge beam carries the rafter loads to posts/bearing points, so rafters do not push the walls outward✓

A structural ridge beam supports the upper ends of the rafters and carries that load down to posts or bearing walls, so the rafters act as supported members and generate no outward thrust, eliminating the need for rafter ties. A ridge board only aligns rafters and offers no vertical support, so ties are required to resist thrust.

Collar ties used to resist wind uplift should be spaced no farther apart than what, measured along the ridge?

• a.12 inches on center
• b.24 inches on center
• c.48 inches on center✓
• d.96 inches on center

Conventional framing provisions limit collar ties (minimum 1x4) to a maximum spacing of 4 feet (48 inches) on center along the ridge. Closer spacings of 12 or 24 inches exceed what is required, and 96 inches is well beyond the permitted maximum.2025 CA Residential Code §R802.4.5

CALCULATION: A common rafter runs horizontally 12 feet from the wall to the ridge and rises 9 feet. Ignoring overhang and cuts, what is the approximate rafter line length?

• a.13 feet
• b.15 feet✓
• c.18 feet
• d.21 feet

The rafter line length is the hypotenuse: the square root of (12 squared + 9 squared) = square root of (144 + 81) = square root of 225 = 15 feet. This is a 3-4-5 triangle scaled by 3. 13 feet ignores the rise, 18 and 21 feet overstate the diagonal.

CALCULATION: A gable roof has a 5:12 slope. If the horizontal run from the wall to the ridge is 24 feet, what is the rafter line length (rounded to the nearest foot, ignoring overhang)?

• a.24 feet
• b.25 feet
• c.26 feet✓
• d.29 feet

At a 5:12 slope, rise = run x 5/12 = 24 x 5/12 = 10 feet. The rafter length is the hypotenuse: square root of (24 squared + 10 squared) = square root of (576 + 100) = square root of 676 = 26 feet. 24 ignores the rise, 25 and 29 miscompute the diagonal.

CALCULATION: A building is 28 feet wide with a central ridge. Ignoring ridge-board thickness, what horizontal run does each common rafter span from the exterior wall to the ridge?

• a.14 feet✓
• b.28 feet
• c.7 feet
• d.21 feet

For a symmetric gable, each common rafter spans half the building width horizontally: 28 / 2 = 14 feet of run (the small ridge-board thickness is ignored here). 28 feet is the full width, 7 feet is a quarter, and 21 feet is three-quarters of the width.

On the jobsite, cutting, notching, or drilling the chords or webs of a prefabricated wood truss is:

• a.Allowed if done neatly with a sharp saw
• b.Allowed for the top chord only
• c.Allowed up to 25 percent of the member
• d.Prohibited unless specifically permitted by the truss design or an engineer✓

Truss members are engineered as a system, so no chord or web may be cut, notched, or drilled unless the truss design drawing or a registered design professional specifically allows it. Neat cutting, top-chord-only cutting, and a 25 percent rule do not apply to engineered trusses.2025 CA Residential Code §R802.10.4

What is the purpose of permanent lateral bracing on the web members of long-span roof trusses?

• a.To carry roofing weight directly to the ground
• b.To prevent the slender web members from buckling and to stabilize the truss system✓
• c.To serve as a walking surface for workers
• d.To replace the need for a ridge board

Permanent web bracing ties the truss webs together so slender compression webs cannot buckle sideways and the truss system stays stable under load. It does not carry roofing to the ground, is not a walkway, and is unrelated to the ridge board, which trusses generally do not use.2025 CA Residential Code §R802.10.3

When a bird's-mouth seat cut is made where a rafter bears on the top plate, what limits how deep that notch may be cut?

• a.It may be cut to any depth to fit the plate
• b.It must remove exactly half the rafter
• c.The remaining rafter depth above the notch must stay adequate; the seat cut should not over-notch the rafter✓
• d.The notch must equal the plate width plus 2 inches

A bird's-mouth seat cut removes material where the rafter sits on the plate, but enough rafter depth must remain above the notch to carry the load, so the cut is limited (commonly the notch does not exceed one-quarter to one-third of the rafter depth per design). Cutting to any depth, exactly half, or plate-width-plus-2 are not the governing limits.2025 CA Residential Code §R802.7

CALCULATION: A hip rafter runs diagonally across the plan corner of a roof. Compared with a common rafter having the same rise, the hip rafter is:

• a.Longer, because its horizontal run is the diagonal of the common rafter's run✓
• b.Shorter, because it is steeper
• c.Exactly the same length
• d.Always half the length of the common rafter

A hip rafter travels along the diagonal of the corner, so its horizontal run is longer (the diagonal of the square formed by the common-rafter runs), making the hip rafter longer than a common rafter of the same rise. It is not shorter, equal, or half length; the diagonal run is what lengthens it.

On a wood I-joist, where may holes generally be cut, and which part must never be cut or notched?

• a.Anywhere in the flange; the web is off-limits
• b.Only in the flange near supports
• c.In the web per the manufacturer's hole chart; the flanges must never be cut or notched✓
• d.Anywhere, because I-joists are solid

An I-joist carries bending through its top and bottom flanges, so the flanges must never be cut or notched; holes are allowed only in the web and only where the manufacturer's hole chart permits. Cutting flanges destroys the joist's capacity, and I-joists are not solid members.2025 CA Residential Code §R502.11

At the bearing ends of many wood I-joists, what component is often required to prevent web crushing or rotation?

• a.Extra roofing felt
• b.Web stiffeners (bearing blocks) and/or blocking panels✓
• c.A thicker subfloor
• d.Additional drywall screws

At supports, I-joist webs can be prone to crushing or the joist to rotation, so manufacturers often require web stiffeners (bearing blocks) fitted in the web and blocking panels or rim board at the ends. Roofing felt, thicker subfloor, and drywall screws do not address I-joist bearing.2025 CA Residential Code §R502.11

For laminated veneer lumber (LVL) and glued-laminated (glulam) beams, where must any holes or notches be located and sized?

• a.Only as permitted by the manufacturer or design professional✓
• b.Anywhere in the middle third
• c.Only within 6 inches of a support
• d.Holes are unlimited because the beam is engineered

Because LVL and glulam are engineered products, holes and notches are allowed only where and as the manufacturer's literature or a design professional specifically permits, since unauthorized cuts can sharply reduce capacity. Blanket middle-third or near-support rules, or unlimited holes, do not apply.2025 CA Residential Code §R502.11

A glued-laminated (glulam) beam is stamped 'TOP' along one edge. Why must it be installed with that face up?

• a.To show the brand logo
• b.Only for appearance
• c.So workers can read the grade stamp later
• d.Because the beam is manufactured with camber and higher-grade laminations to be on the correct side for the load✓

Glulams are built with a slight upward camber and with stronger tension laminations placed for the intended loading, so installing the 'TOP' edge up puts the camber and lamination layout in the correct orientation to resist load and deflection. Logo visibility, appearance, and reading the stamp are not the structural reason.

What minimum bearing length is commonly required at the ends of engineered wood floor members unless the manufacturer specifies otherwise?

• a.1/2 inch
• b.About 1-1/2 inches on wood or metal (and more on masonry), per the manufacturer✓
• c.4 inches minimum always
• d.No bearing is needed if hangers are used

Engineered floor members typically need on the order of 1-1/2 inches of end bearing on wood or metal (and more on masonry or concrete), following the manufacturer's tables, so the reaction is safely delivered. A 1/2 inch is too little, a flat 4-inch rule is not universal, and hangers still require adequate seat or nailing capacity.2025 CA Residential Code §R502.6

At the ends of I-joists that rest on a wall, a continuous member closing the joist ends and transferring vertical/lateral load is called what?

• a.A ledger
• b.A collar tie
• c.A rim board (rim joist)✓
• d.A purlin

A rim board (rim joist) runs continuously along the ends of I-joists, closing the floor, providing bearing for the wall above, and transferring vertical and lateral loads. A ledger attaches a structure to a wall, a collar tie is a roof member, and a purlin supports rafters.2025 CA Residential Code §R502.11

Where a concentrated load (such as a post from above) bears down over an I-joist at a support, what is often installed to carry that load past the joist without crushing it?

• a.Squash blocks (vertical blocks slightly taller than the joist depth) beside the joist✓
• b.A single drywall screw
• c.Extra roofing nails
• d.A layer of building paper

Squash blocks are short vertical members set beside the I-joist at a bearing point, cut just proud of the joist depth so the concentrated load bypasses the I-joist web and transfers directly to the support below. A screw, roofing nails, or building paper cannot carry a concentrated vertical load.2025 CA Residential Code §R502.11

CALCULATION: An engineered LVL header is specified as a 3-1/2 inch wide member built up from plies that are each 1-3/4 inch thick. How many plies are laminated together?

• a.1 ply
• b.2 plies✓
• c.3 plies
• d.4 plies

Total width divided by ply thickness: 3.5 / 1.75 = 2 plies. A single 1-3/4 inch ply gives only 1-3/4 inch, three plies give 5-1/4 inch, and four plies give 7 inch, none of which equals the specified 3-1/2 inch width.

Engineered rim board is often chosen over solid sawn lumber at the perimeter of an I-joist floor mainly because it:

• a.Is always cheaper
• b.Needs no fasteners
• c.Is fire-rated by itself
• d.Matches the depth of the I-joists and provides consistent, rated vertical load transfer around the floor✓

Engineered rim board is manufactured to match I-joist depths and to carry the rated vertical and lateral loads uniformly around the floor perimeter, avoiding the shrinkage and depth-mismatch problems of solid lumber. Cost, fastener-free installation, and inherent fire rating are not the governing reasons.2025 CA Residential Code §R507.5

Compared with solid-sawn joists, why are field notches and unauthorized holes especially damaging to engineered wood products such as I-joists and LVL?

• a.They are made of steel
• b.They are unaffected by cuts
• c.Their strength depends on thin engineered flanges/laminations, so unauthorized cuts remove critical load-carrying material✓
• d.They gain strength when cut

Engineered products concentrate their strength in thin, carefully placed flanges and laminations, so an unauthorized notch or hole removes exactly the material carrying the load and can cause sudden failure, unlike solid lumber that has some reserve. They are not steel, are certainly affected by cuts, and never gain strength from cutting.2025 CA Residential Code §R502.8

On braced/shear walls, code requires a plate washer at each anchor bolt between the sill plate and nut. A common minimum size is:

• a.1 inch by 1 inch by 1/16 inch
• b.3 inch by 3 inch by 0.229 inch✓
• c.2 inch round by 1/8 inch
• d.No washer is needed if a nut is used

For braced-wall sill anchorage in seismic areas, the code commonly requires a plate washer at least 3 inch by 3 inch by 0.229 inch thick under the nut, so seismic uplift cannot pull the sill over the bolt head. A tiny 1x1 or thin round washer is inadequate, and a nut alone does not spread the load.2025 CA Residential Code §R602.11.1

For a bolted sill plate, the code requires a minimum number of anchor bolts per plate piece and a limit on bolt distance from plate ends. Which statement is correct?

• a.One bolt per plate is always enough
• b.Bolts may be placed only at the exact center
• c.End distance does not matter
• d.At least two bolts per plate piece, with a bolt located near each end (commonly within 12 inches, but not less than about seven bolt diameters, of each end)✓

Each sill-plate piece must have at least two anchor bolts, with one near each end (typically within 12 inches of the end but not closer than roughly seven bolt diameters), so short pieces cannot pivot or lift free. One bolt, center-only placement, and ignoring end distance all violate the anchorage rules.2025 CA Residential Code §R403.1.6

CALCULATION: A sill plate on a 30-foot wall uses anchor bolts spaced at the 6-foot maximum, with a bolt required near each end. Approximately how many anchor bolts are needed along that wall?

• a.4 bolts
• b.5 bolts
• c.6 bolts✓
• d.10 bolts

With bolts at 6 feet on center over 30 feet, the spacing gives 30/6 = 5 intervals, which needs 5 + 1 = 6 bolts to also place one near each end. Four or five bolts would leave spacing or end distances too great, and ten bolts far exceeds the 6-foot maximum spacing.

In a wood-framed building, what is the PRIMARY role of a floor or roof diaphragm in the lateral system?

• a.To collect lateral (wind/seismic) forces and transfer them horizontally to the shear walls✓
• b.To carry only gravity floor loads
• c.To provide the finished floor surface
• d.To insulate the floor cavity

A diaphragm is the horizontal sheathed floor or roof plane that collects wind and seismic forces and distributes them to the vertical shear walls that carry them to the foundation. Gravity load, finish surface, and insulation are separate functions, not the diaphragm's lateral role.

At the ends of a shear wall, why is blocking installed at horizontal panel joints in a 'blocked' shear wall?

• a.To hold insulation in place
• b.To provide continuous framing so panel edges can be nailed and shear can transfer across the joint✓
• c.To act as fireblocking only
• d.To hang the drywall

In a blocked shear wall, solid blocking behind horizontal panel joints gives every panel edge continuous framing to nail to, allowing the wall to reach its higher rated shear capacity by transferring load across the joint. Insulation support, fireblocking, and drywall hanging are not the structural purpose of shear-wall edge blocking.2025 CA Residential Code §R602.10.8

In a continuous load path for lateral loads, what is the main job of metal straps that connect wall framing across a floor level (stacked walls)?

• a.To level the floor
• b.To carry plumbing across floors
• c.To tie upper and lower wall segments together so uplift and overturning forces pass continuously to the foundation✓
• d.To provide a nailing surface for baseboard

Straps across a floor level splice the upper wall to the lower wall so uplift and overturning tension travels down through each story to the foundation, maintaining a continuous load path. Leveling, plumbing support, and baseboard nailing are not the purpose of these tension straps.2025 CA Residential Code §R602.10.6

In a seismic retrofit of an older house with a raised foundation, what two upgrades are MOST commonly added to the cripple wall and sill to resist earthquake movement?

• a.New roofing and gutters
• b.Larger windows and doors
• c.Interior paint and trim
• d.Structural panel sheathing on the cripple wall and anchor bolts (or plates) connecting the sill to the foundation✓

The classic soft-story cripple-wall retrofit adds wood structural panel bracing to the short cripple wall and anchor bolts or foundation plates tying the sill to the concrete, so the house cannot slide off or the cripple wall collapse in a quake. Roofing, windows, and paint do not address this lateral weakness.2025 CA Existing Building Code

What is the main purpose of a hold-down (tie-down) anchor at the end post of a narrow shear wall?

• a.To resist the uplift/overturning tension generated at the wall end and anchor it to the foundation✓
• b.To level the top plate
• c.To provide gravity bearing for the roof
• d.To seal the wall against air leaks

A hold-down connects the end post (chord) of a shear wall to the foundation and resists the tension uplift that lateral load creates as the wall tries to overturn, which is critical on narrow walls with high overturning. Leveling, gravity bearing, and air sealing are not the hold-down's function.2025 CA Residential Code §R602.10.6.2

A 'collector' or 'drag strut' in a lateral system does what?

• a.Collects rainwater from the roof
• b.Provides gravity support only
• c.Gathers diaphragm forces and 'drags' them into the shear wall that is shorter than the diaphragm edge✓
• d.Serves as a decorative beam

A collector (drag strut) is a framing member that gathers the lateral force along a diaphragm edge and delivers it into a shear wall that does not run the full length of that edge, keeping the load path continuous. It has nothing to do with rainwater, gravity-only support, or decoration.2025 CA Residential Code §R602.10

To transfer shear from a diaphragm or wall into the framing, the connection of sheathing to the boundary members depends MOST on which factor?

• a.The color of the sheathing
• b.The nail size, spacing, and edge distance along the boundary✓
• c.The brand of the lumber
• d.The paint on the studs

Shear transfer at a boundary is governed by the fastening: nail size, spacing, and adequate edge distance along the boundary members determine how much shear the connection can move without splitting or pulling through. Sheathing color, lumber brand, and paint have no effect on shear transfer.2025 CA Residential Code §R602.3.1

Behind exterior cement plaster (stucco) applied over wood-based sheathing, how many layers of water-resistive barrier does the code generally require?

• a.One layer
• b.Two layers of a water-resistive barrier (for example, two layers of Grade D paper)✓
• c.No barrier if the stucco is thick enough
• d.Only a vapor barrier on the inside

Over wood-based sheathing, stucco assemblies generally require two layers of water-resistive barrier, because fresh stucco bonds to and can compromise the first layer, so the second layer maintains a continuous drainage plane. One layer, no barrier, and an interior-only vapor barrier do not meet the two-layer stucco requirement.2025 CA Residential Code §R703.6.3

A weep screed at the base of a stucco wall must be located at least how far above adjacent surfaces?

• a.At least 4 inches above earth or 2 inches above paved areas✓
• b.At least 12 inches above earth
• c.Flush with the finished grade
• d.At least 8 inches above paved areas

The foundation weep screed must sit a minimum of 4 inches above earth or 2 inches above paved surfaces so moisture in the stucco can drain out above the splash and grade line. Twelve inches, flush with grade, and 8 inches above paving are not the code-required minimums.2025 CA Residential Code §R703.6.2.1

CALCULATION: Cement plaster control joints are recommended to divide large wall areas into panels not exceeding 144 square feet. On a wall panel 8 feet tall, at about what horizontal spacing should control joints fall to stay within that limit?

• a.6 feet
• b.12 feet
• c.18 feet✓
• d.24 feet

Area = height x length, so length = 144 / 8 = 18 feet. Control joints spaced about 18 feet apart keep each 8-foot-tall panel at roughly 144 square feet. Six or twelve feet would create smaller panels than required, and 24 feet gives 192 square feet, exceeding the 144-square-foot guideline.

When metal lath for three-coat stucco is fastened to a wood-framed wall, how far should the fasteners penetrate the framing?

• a.Just into the sheathing
• b.No penetration is needed if the lath is tight
• c.Only into the WRB
• d.Into the studs or supports far enough to hold the lath securely (commonly at least about 3/4 to 1 inch)✓

Lath fasteners must reach into the studs or solid supports enough (commonly on the order of 3/4 to 1 inch) so the lath and the heavy wet plaster cannot pull loose. Fastening only to sheathing, to the WRB, or relying on tight lath without penetration will not hold the plaster.2025 CA Residential Code §R703.7

In traditional three-coat stucco over metal lath, the total nominal thickness is about 7/8 inch. Which sequence of coats builds that thickness?

• a.Scratch coat, brown coat, then finish coat✓
• b.Finish coat, brown coat, then scratch coat
• c.Two brown coats and one scratch coat
• d.A single thick coat troweled to 7/8 inch

Three-coat stucco is applied as a scratch coat (scored to bond the next coat), a brown coat (bringing the wall to plane), and a finish coat, totaling about 7/8 inch over metal lath. Reversing the order, doubling the brown coat, or applying one thick coat are not the standard three-coat method.2025 CA Residential Code §R703.7

Fiber-cement lap siding is installed on a wood-framed wall. What clearance is generally required between the bottom edge of the siding and the finished grade or a roof surface below it?

• a.No clearance; siding may touch the ground
• b.A clearance (commonly around 6 inches to earth and about 1 to 2 inches above a roof) to keep the siding out of standing water and splash✓
• c.At least 12 inches above a roof
• d.Siding must be buried 2 inches into the grade

Manufacturers and the code call for clearance at the bottom of fiber-cement (and most) siding, commonly about 6 inches to earth and roughly 1 to 2 inches above roof surfaces, to keep the siding out of standing water and splash that would wick moisture. No clearance, 12 inches above a roof, or burying the siding are incorrect.2025 CA Residential Code §R703.3

Why is vinyl siding fastened so that the panels can move slightly (nails not driven tight) rather than pinned firmly?

• a.To make installation faster only
• b.Because vinyl is structural sheathing
• c.To allow for thermal expansion and contraction so panels do not buckle or crack✓
• d.Because vinyl needs no water-resistive barrier

Vinyl expands and contracts significantly with temperature, so nails are left slightly loose and centered in slots to let the panels move; pinning them tight causes buckling in heat and cracking in cold. Speed, structural function, and skipping the WRB are not the reasons for loose fastening.2025 CA Residential Code §R703.4

Where three-coat stucco terminates at a window, door, or dissimilar material, what accessory provides a clean, sealed edge?

• a.A weep screed only
• b.A rafter tie
• c.A drip edge on the roof
• d.A casing bead (plaster stop) at the termination✓

A casing bead, or plaster stop, gives stucco a finished, gauged edge where it terminates against openings or other materials and creates a location to seal against water intrusion. A weep screed is used at the wall base, a rafter tie is a roof member, and a roof drip edge is unrelated to a wall stucco termination.2025 CA Residential Code §R703.7.3

When self-furring metal lath is used for stucco, what does the 'self-furring' feature accomplish?

• a.It holds the lath slightly off the backing so plaster can key fully behind the mesh✓
• b.It eliminates the need for fasteners
• c.It replaces the scratch coat
• d.It makes the lath waterproof

Self-furring lath has dimples or ridges that stand it off the backing a small distance, so the first (scratch) coat is pushed through and keys fully behind the mesh for a strong bond. It does not remove the need for fasteners, replace the scratch coat, or make the lath waterproof.2025 CA Residential Code §R703.6.1

A deck ledger is attached to the house rim joist. Which fastening is generally ACCEPTABLE, and which is NOT?

• a.Toenails driven at an angle are acceptable
• b.Standard drywall screws are acceptable
• c.Through-bolts or approved lag screws in a prescribed pattern are acceptable; nails alone are not✓
• d.Any construction adhesive alone is acceptable

A deck ledger must be fastened with through-bolts or approved lag screws laid out per the code table, because they resist the tension pulling the deck away from the house; nails, drywall screws, toenails, or adhesive alone cannot safely carry those loads and are prohibited for ledger attachment.2025 CA Residential Code §R507.9.1.3

What flashing detail BEST protects the house at a deck ledger connection?

• a.No flashing, just caulk the top
• b.Corrosion-resistant flashing that directs water out over the ledger and integrates with the wall's water-resistive barrier✓
• c.A strip of untreated cardboard
• d.Painting the ledger black

Proper ledger flashing is a corrosion-resistant metal or approved flashing lapped so water sheds out and away over the top of the ledger and integrates with the WRB, preventing rot behind the ledger. Caulk alone, cardboard, or paint do not create a durable, integrated drainage detail.2025 CA Residential Code §R507.9.1.4

For a wood deck post that carries deck loads down to a footing, which connection detail is MOST important at the base?

• a.The post may simply rest on soil
• b.The post should be buried in the ground without treatment
• c.A decorative cap is all that is required
• d.A post base/anchor that ties the post to the footing and resists uplift and lateral movement✓

A code-compliant deck post uses a metal post base or anchor connecting it to the concrete footing so the post cannot slide off or lift, transferring gravity, uplift, and lateral loads. Resting on soil, burying untreated wood, or relying on a decorative cap does not provide the required structural connection.2025 CA Residential Code §R507.4

CALCULATION: A deck uses 2x8 pressure-treated joists of a species with a span table value of 12 feet at 16 inches on center. If the framer moves the joists to 12 inches on center, the allowable span will generally:

• a.Increase somewhat, because closer joists each carry less load✓
• b.Decrease to zero
• c.Stay exactly the same
• d.Double to 24 feet

Spacing joists closer together (16 to 12 inches on center) gives each joist a smaller tributary load, so span tables allow a somewhat longer span at the tighter spacing. It does not drop to zero, stay identical, or double; the increase is modest, per the table, not a doubling.2025 CA Residential Code §R507.6

Where a deck beam bears on a supporting post, what is the BEST practice for the connection?

• a.Set the beam beside the post and rely on nails to hold it up
• b.Balance the beam on top of a single nail
• c.Seat the beam so it bears on top of the post (or in an approved saddle/cap) with a positive connection to resist uplift and displacement✓
• d.Use adhesive only

Best practice seats the deck beam directly on top of the post or in an approved post cap/saddle so gravity load bears in compression, with a mechanical connection (bolts or an approved cap) resisting uplift and sideways movement. Side-nailing the beam, balancing on a nail, or adhesive alone are unsafe connections.2025 CA Residential Code §R507.5

Besides the ledger fasteners, the code requires a lateral load connection between the deck and the house structure. What does this connection primarily prevent?

• a.Squeaky deck boards
• b.The deck pulling away from the house under lateral load✓
• c.Rain from reaching the ledger
• d.Insect damage

The lateral load connection (typically hold-down tension devices anchored into the house floor framing) resists the horizontal force that would pull a deck away from the house, a common cause of catastrophic deck collapses. It is not about squeaks, rain, or insects, which other details address.2025 CA Residential Code §R507.9.2

On a raised residential deck, guards are required, and the guard infill (balusters/pattern) must be designed so that which object cannot pass through?

• a.A 6-inch sphere
• b.A basketball
• c.A 5-inch sphere
• d.A 4-inch sphere✓

Deck and balcony guard openings must be small enough that a 4-inch-diameter sphere cannot pass through the infill, protecting small children. A 6-inch or 5-inch sphere limit is too loose for guard infill (6 inches applies only to the triangle at open stairs), and 'a basketball' is not a code criterion.2025 CA Residential Code §R507.7

Why must deck framing lumber in contact with the weather and near the ground be pressure-preservative-treated or naturally durable?

• a.To resist decay and insect attack in the exposed, moist environment✓
• b.To make it lighter
• c.To improve its color
• d.To make painting unnecessary

Exterior deck lumber sits in a wet, exposed environment where untreated wood rots and is attacked by insects, so it must be preservative-treated or a naturally durable species to last. Treatment is not about reducing weight, improving color, or eliminating the option to paint or finish.2025 CA Residential Code §R507.2

CALCULATION: A stairway must rise a total of 112 inches from finished floor to finished floor. Using the 7-3/4 inch maximum riser height, what is the MINIMUM number of risers required?

• a.13 risers
• b.14 risers
• c.15 risers✓
• d.16 risers

Divide total rise by the maximum riser: 112 / 7.75 = 14.45, which must round UP to 15 risers so each riser stays at or below 7-3/4 inch (112 / 15 = 7.47 inch). Thirteen or fourteen risers would exceed the maximum height, and 16 is more than the minimum needed.2025 CA Residential Code §R311.7.5.1

CALCULATION: A stair has 15 risers. Using a 10-inch tread depth, what is the total horizontal run of the flight (number of treads times tread depth)?

• a.150 inches
• b.140 inches✓
• c.110 inches
• d.160 inches

A straight flight has one fewer tread than risers: 15 - 1 = 14 treads. Total run = 14 x 10 inch = 140 inches. Using 15 treads (150 inches) forgets that the top riser lands on the floor, 110 and 160 inches use the wrong tread count.2025 CA Residential Code §R311.7.5.2

CALCULATION: A roof area of 200 square feet is subject to a net wind uplift pressure of 15 pounds per square foot. What total uplift force must the connections in that area resist?

• a.1,500 pounds
• b.215 pounds
• c.13 pounds
• d.3,000 pounds✓

Total force = pressure x area = 15 psf x 200 sq ft = 3,000 pounds. The connections (straps, ties, anchors) in that area must resist that 3,000-pound uplift. 1,500 pounds halves the area or pressure, 215 pounds adds instead of multiplies, and 13 pounds divides incorrectly.

At the top and bottom of a residential stairway, a floor or landing is required. What is the MINIMUM dimension of that landing measured in the direction of travel?

• a.36 inches✓
• b.24 inches
• c.30 inches
• d.48 inches

A stairway landing must be at least 36 inches measured in the direction of travel, giving a safe place to pause and change direction. Twenty-four and thirty inches are too small, and 48 inches is more than the code minimum (though it may be provided).2025 CA Residential Code §R311.7.6

For a circular (Type I) handrail, what is the required graspable cross-section?

• a.Any size, as long as it is smooth
• b.An outside diameter of at least 1-1/4 inch and not more than 2 inches✓
• c.At least 3 inches in diameter
• d.Exactly 1 inch in diameter

A circular handrail must have an outside diameter between 1-1/4 inch and 2 inches so a hand can close around it securely. 'Any size,' a 3-inch diameter (too large to grasp), and a fixed 1-inch (below the minimum) do not meet the graspability requirement.2025 CA Residential Code §R311.7.8.5

A required stair handrail must be continuous along the flight. How should the ends of the handrail be treated?

• a.Left open with sharp ends
• b.Cut off flush at the top step only
• c.Returned to the wall or terminated in a newel/safety terminal so clothing cannot catch✓
• d.Removed at the landing

Handrail ends must return to the wall or end in a newel post or safety terminal so that loose clothing, bags, or hands cannot catch on an open end. Leaving sharp open ends, cutting off only at the top, or removing the rail at the landing all create hazards and break continuity.2025 CA Residential Code §R311.7.8.4

On a stair with solid risers and treads less than 11 inches deep, a nosing is required. What projection range does the code specify for that nosing?

• a.0 to 1/4 inch
• b.1 to 2 inches
• c.2 to 3 inches
• d.3/4 inch to 1-1/4 inch✓

Where a nosing is required, it must project between 3/4 inch and 1-1/4 inch beyond the riser below, giving extra effective foot depth without becoming a trip hazard. The other ranges are either too small to help or so large they create a catch point and are not code-compliant.2025 CA Residential Code §R311.7.5.3

CALCULATION: Two stair carriages (stringers) are each cut from a 2x12 that is 14 feet long. Using nominal dimensions, how many total board feet of lumber is that?

• a.28 board feet
• b.42 board feet
• c.56 board feet✓
• d.21 board feet

Board feet per piece = (nominal thickness in inches x nominal width in inches x length in feet) / 12 = (2 x 12 x 14) / 12 = 28 board feet each. Two stringers = 2 x 28 = 56 board feet. 28 counts only one piece, 42 and 21 use the wrong figures.

A spiral stairway is permitted in a dwelling under special rules. Which requirement is characteristic of a code-compliant spiral stair?

• a.Treads must be at least 11 inches deep at every point
• b.Each tread provides a minimum run at a defined walk-line point (about 12 inches from the narrow edge) and headroom is at least 6 feet 6 inches✓
• c.Risers may be any height with no limit
• d.No center column is allowed

Spiral stairs are allowed with special geometry: the tread depth is measured at a walk line roughly 12 inches from the narrower edge and must meet a minimum there, with reduced but defined headroom of at least 6 feet 6 inches. Uniform 11-inch treads, unlimited risers, and a no-center-column rule do not describe a spiral stair.2025 CA Residential Code §R311.7.10.1

For a conventionally framed one-story dwelling using 2x4 studs, what is the MAXIMUM on-center spacing generally permitted for load-bearing wall studs supporting a roof and ceiling only?

• a.12 inches
• b.24 inches✓
• c.32 inches
• d.48 inches

The residential code stud tables allow 2x4 bearing studs supporting roof and ceiling to be spaced up to 24 inches on center. 12 inches is more conservative than required and wastes material; 32 and 48 inches exceed the tabulated maximum for 2x4 bearing studs and would over-stress the wall.2025 CA Residential Code §R602.3.1

When installing tongue-and-groove wood structural panel subflooring, which practice BEST reduces squeaks and improves diaphragm performance?

• a.Butting panel edges tightly with no gap
• b.Nailing only at panel corners
• c.Gluing the panels to the joists in addition to fastening✓
• d.Laying all end joints on a single joist in a continuous line

Field-gluing the subfloor to the joists with construction adhesive in addition to nailing or screwing greatly reduces squeaks and stiffens the diaphragm. Panel edges need a small expansion gap, not a tight butt; fastening only at corners leaves the field unsupported; and aligning all end joints on one line creates a weak, hinge-like seam rather than a staggered layout.2025 CA Residential Code §R503

A gable roof has a total run of 12 feet (horizontal from wall to ridge) and a slope of 6:12. Ignoring ridge and overhang, what is the approximate line length of a common rafter along the slope?

• a.About 13 feet 5 inches✓
• b.About 12 feet 0 inches
• c.About 15 feet 0 inches
• d.About 6 feet 0 inches

Rafter line length equals run times the unit-length factor. For a 6:12 slope the diagonal per 12 units of run is the square root of (12² + 6²) = 13.416 units, a factor of about 1.118. Multiply 12 ft run by 1.118 to get roughly 13.42 ft, or about 13 ft 5 in. 12 ft ignores the slope; 15 ft overshoots; 6 ft is the rise, not the rafter length.2025 CA Residential Code §R802

Under the residential code, what is the MAXIMUM permitted riser height for a stairway serving a dwelling?

• a.6 inches
• b.7 inches
• c.7 1/2 inches
• d.7 3/4 inches✓

The residential code caps riser height at 7 3/4 inches for stairs within dwellings. 6 and 7 inches are allowable but not the maximum; 7 1/2 inches is close but still below the code ceiling. Note the commercial building code uses a lower 7-inch maximum, so the value depends on occupancy.2025 CA Residential Code §R311.7.5

For a dwelling stairway, what is the MINIMUM tread depth (run) required, measured horizontally between the leading edges of adjacent treads?

• a.9 inches
• b.10 inches✓
• c.11 inches
• d.12 inches

The residential code requires a minimum tread depth of 10 inches for dwelling stairs. 9 inches is below the minimum and would be too steep; 11 and 12 inches exceed the minimum and are acceptable but not the required floor value. The commercial code requires a deeper 11-inch tread.2025 CA Residential Code §R311.7.5

Guards on open sides of walking surfaces in a dwelling must be at least what height above the walking surface or, for stairs, the line connecting the tread nosings?

• a.30 inches
• b.34 inches
• c.36 inches✓
• d.42 inches

The residential code sets a minimum guard height of 36 inches for dwellings. 30 inches is the trigger height at which a guard becomes required, not the guard height itself; 34 inches is a handrail height, not a guard height; 42 inches is the commercial guard height, higher than the residential minimum.2025 CA Residential Code §R312.1.2

A required stair handrail must be mounted so its top is within what vertical range above the tread nosings?

• a.34 to 38 inches✓
• b.30 to 34 inches
• c.36 to 42 inches
• d.42 to 48 inches

Handrail top height must be between 34 and 38 inches measured vertically from the nosing line. 30 to 34 inches is too low; 36 to 42 and 42 to 48 inches are too high and overlap guard heights rather than handrail heights.2025 CA Residential Code §R311.7.8

For a conventionally framed wall anchored to a concrete foundation, anchor bolts of at least 1/2-inch diameter must generally be spaced no more than what distance on center?

• a.4 feet
• b.6 feet✓
• c.8 feet
• d.10 feet

The residential code generally requires 1/2-inch anchor bolts at a maximum of 6 feet on center, with a bolt located within 12 inches of each plate end. 4 feet is more conservative than required; 8 and 10 feet exceed the maximum spacing and would under-anchor the sill plate against uplift and sliding.2025 CA Residential Code §R403.1.6

In a wood-framed shear wall resisting seismic loads, what is the PRIMARY function of a hold-down device installed at the wall ends?

• a.To level the top plate during framing
• b.To provide a nailing surface for siding
• c.To resist overturning uplift and anchor the end post to the foundation✓
• d.To act as a vapor barrier at the wall base

A hold-down ties the shear wall's end post (chord) to the foundation to resist the uplift produced when lateral forces try to overturn the wall. It does not level plates, provide siding nailing, or act as a vapor barrier; those are unrelated framing or moisture functions.2025 CA Residential Code §R602.10

When applying three-coat Portland cement plaster (stucco) over wood framing on an exterior wall, a weep screed must be installed at the foundation plate line at least how far above the earth?

• a.1 inch above earth
• b.2 inches above earth
• c.3 inches above earth
• d.4 inches above earth (or 2 inches above paved surfaces)✓

A corrosion-resistant weep screed must be placed a minimum of 4 inches above earth or 2 inches above paved areas to let moisture drain out of the wall assembly. 1, 2, and 3 inches above earth are insufficient clearance and could wick soil moisture into the plaster and framing.2025 CA Residential Code §R703.7.2.1

Traditional three-coat stucco applied over metal lath on a framed wall should have what approximate MINIMUM total nominal thickness measured from the face of the lath?

• a.7/8 inch✓
• b.3/8 inch
• c.1/4 inch
• d.1 1/2 inches

Three-coat stucco (scratch, brown, and finish coats) is built to a nominal total thickness of about 7/8 inch measured from the face of the lath. 3/8 and 1/4 inch are far too thin for a three-coat system, and 1 1/2 inches is thicker than standard and unnecessary.2025 CA Residential Code §R703.7

To resist lateral separation of an exterior wood deck from the dwelling during seismic or live loads, which connection is the BEST practice at the ledger-to-band-joist interface?

• a.Rely solely on the deck ledger lag screws for lateral resistance
• b.Install tension hold-down devices connecting the deck framing to the interior floor framing✓
• c.Use construction adhesive between the ledger and the house wall
• d.Toenail the joists into the ledger at each bay

Code-recognized lateral load connectors (tension devices) tie the deck joists through the wall to the interior floor framing, directly resisting the deck pulling away. Ledger lag screws primarily carry vertical shear, not lateral tension; adhesive is not a rated structural connection; and toenailing alone is far too weak for lateral loads.2025 CA Residential Code §R507

How many board feet are contained in ten framing members that are each 2 inches thick, 6 inches wide, and 12 feet long?

• a.60 board feet
• b.100 board feet
• c.120 board feet✓
• d.144 board feet

Board feet per piece equals (thickness in inches x width in inches x length in feet) divided by 12: (2 x 6 x 12) / 12 = 12 board feet each. Ten pieces total 120 board feet. 60 is the count for five pieces; 100 and 144 do not match the calculation.

In high-wind and seismic regions, what is the MAIN purpose of installing metal framing anchors (hurricane or seismic ties) connecting each rafter or truss to the top plate?

• a.To speed alignment of the ridge board
• b.To provide a ground path for lightning
• c.To replace the need for roof sheathing nails
• d.To resist uplift and lateral forces that could separate the roof from the walls✓

Rafter or truss ties create a continuous load path that resists wind uplift and seismic forces trying to pull the roof off the walls. They do not align the ridge, ground lightning, or substitute for sheathing fasteners, all of which serve different structural or safety roles.2025 CA Residential Code §R802.11

When prefabricated wood roof trusses are delivered to a jobsite, which practice BEST preserves their engineered performance?

• a.Install them only per the truss manufacturer's engineered layout and bracing plan✓
• b.Field-cut chords or webs as needed to fit obstructions
• c.Notch the bottom chord to run plumbing without approval
• d.Store them flat-stacked in mud until installation

Trusses are engineered assemblies that must be installed and braced exactly per the manufacturer's layout and bracing design. Field-cutting chords or webs, notching the bottom chord, or storing them improperly all compromise the engineered load path and can void the design and cause failure.2025 CA Residential Code §R802.3

What is the MINIMUM headroom clearance required over a residential stairway, measured vertically from the tread nosing line?

• a.6 feet 4 inches
• b.6 feet 8 inches✓
• c.7 feet 0 inches
• d.7 feet 6 inches

The residential code requires a minimum 6 feet 8 inches of headroom above the stair, measured vertically from a line connecting the tread nosings. 6 feet 4 inches is below the minimum; 7 feet 0 inches and 7 feet 6 inches exceed the requirement and are not the code floor value.2025 CA Residential Code §R311.7.2

What is the MINIMUM clear width required above the handrail for an interior residential stairway?

• a.30 inches
• b.32 inches
• c.36 inches✓
• d.44 inches

Residential stairs must provide a minimum clear width of 36 inches above the permitted handrail height. 30 and 32 inches are narrower than allowed; 44 inches is a common commercial minimum and exceeds the residential requirement.2025 CA Residential Code §R311.7.1

Guards required on decks and balconies must have intermediate rails or ornamental patterns such that a sphere of what MAXIMUM diameter cannot pass through the openings?

• a.6 inches
• b.5 inches
• c.4 3/8 inches
• d.4 inches✓

Guard openings must not allow passage of a 4-inch-diameter sphere, limiting the gap so small children cannot slip through. 6, 5, and 4 3/8 inches all exceed the 4-inch limit and would leave unsafe openings.2025 CA Residential Code §R312.1.3

In conventional platform framing, what is the PRIMARY structural role of the double top plate on a bearing wall?

• a.To tie wall segments together and distribute loads from rafters or joists above✓
• b.To serve as a nailing base for baseboard trim
• c.To provide the finished ceiling line
• d.To act as a fire sprinkler mounting rail

The double top plate laps at corners and intersections to tie wall segments into a continuous unit and distribute point and uniform loads from framing above. It is not for baseboard nailing, ceiling finish, or sprinkler mounting, which are unrelated to its load-transfer purpose.2025 CA Residential Code §R602.3

When installing horizontal lap siding, which practice BEST manages moisture behind the cladding?

• a.Seal all vertical joints airtight with no flashing
• b.Install a water-resistive barrier and lap the siding to shed water over the course below✓
• c.Nail the siding tight with no gap so no water can enter
• d.Apply siding directly to studs without sheathing or barrier

Lap siding works with a water-resistive barrier and proper lapping so any water is directed outward and downward over the course below. Sealing joints airtight traps moisture, nailing tight ignores the drainage principle, and omitting sheathing and a barrier leaves the wall unprotected.2025 CA Residential Code §R703.3

A stair must rise a total of 108 inches from finished floor to finished floor. If each riser is designed at 7.2 inches, how many risers are required?

• a.12 risers
• b.14 risers
• c.15 risers✓
• d.18 risers

Number of risers equals total rise divided by riser height: 108 / 7.2 = 15 risers exactly. 12 risers would give a 9-inch riser (too tall); 14 risers gives about 7.7 inches (acceptable but not the designed 7.2); 18 risers gives only 6 inches, more than designed.

When a plumbing or mechanical run requires boring holes in load-bearing wall studs, the code limits bored hole diameter to no more than what fraction of the stud depth for a bearing wall?

• a.70 percent
• b.60 percent
• c.50 percent
• d.40 percent✓

For bearing wall studs, bored holes may not exceed 40 percent of the stud depth (with stricter limits and reinforcement rules beyond that). 70, 60, and 50 percent all exceed the allowance for bearing studs and would unduly weaken the member. Nonbearing studs allow a larger 60 percent bore.2025 CA Residential Code §R602.6

For exterior wood decks, which material designation BEST indicates lumber suitable for the wet, ground-contact exposure of deck posts set near grade?

• a.Preservative-treated lumber rated for ground contact✓
• b.Kiln-dried interior-grade lumber
• c.Untreated standard framing lumber
• d.Finger-jointed trim stock

Deck posts near grade require preservative-treated lumber rated for ground contact to resist decay and insects. Kiln-dried interior lumber, untreated framing lumber, and finger-jointed trim are all unsuited to sustained moisture and will deteriorate.2025 CA Residential Code §R507.2

In a braced wall line using wood structural panel sheathing, which nailing change MOST directly increases the shear capacity of the wall?

• a.Increasing panel edge nail spacing from 4 to 6 inches
• b.Decreasing panel edge nail spacing from 6 to 4 inches✓
• c.Removing nails at the panel field
• d.Using a smaller-diameter nail at the same spacing

Tighter edge nailing, such as reducing spacing from 6 to 4 inches on center, transfers more shear per foot and increases the wall's capacity. Widening the spacing, removing field nails, or using thinner nails all reduce capacity rather than increase it.2025 CA Residential Code §R602.10.4

A common rafter has a horizontal run of 10 feet and a rise of 5 feet. What is the roof slope expressed as unit rise per 12 units of run?

• a.3:12
• b.4:12
• c.6:12✓
• d.12:12

Slope in rise-per-12 equals (rise / run) x 12 = (5 / 10) x 12 = 6, so the slope is 6:12. 3:12 and 4:12 are shallower than the actual ratio, and 12:12 would require the rise to equal the run.

In conventional roof framing with rafters bearing on exterior walls, what is the PRIMARY purpose of ceiling joists or an equivalent tie connecting opposing rafters?

• a.To support the finished roofing weight only
• b.To provide attic storage capacity
• c.To align the ridge board vertically
• d.To resist rafter thrust that would otherwise push the walls outward✓

Ceiling joists or rafter ties act in tension to resist the outward thrust that sloped rafters exert on the walls at their bearing. They are not solely for roofing weight, attic storage, or ridge alignment; without the tie the walls could spread and the ridge could sag.2025 CA Residential Code §R802.4

When anchoring wood ledgers or sill plates to masonry or concrete in a seismic design category, which fastener detail is MOST important for load transfer?

• a.Using properly sized and embedded anchors with edge distance and spacing per the approved design✓
• b.Relying on masonry nails driven by hand
• c.Attaching with construction adhesive alone
• d.Using a single anchor centered on the plate

Load transfer into masonry or concrete depends on correctly sized anchors installed to the design embedment, edge distance, and spacing. Hand-driven masonry nails, adhesive alone, or a single central anchor cannot develop the required capacity and violate the engineered detailing.2025 CA Residential Code §R606

On a residential stairway, the MAXIMUM allowable variation between the largest and smallest riser height within a single flight is generally limited to what value?

• a.1/8 inch
• b.3/8 inch✓
• c.3/4 inch
• d.1 inch

Uniformity rules limit the difference between the largest and smallest riser (and largest and smallest tread) in a flight to no more than 3/8 inch, preventing trip hazards from uneven steps. 1/8 inch is stricter than required, while 3/4 inch and 1 inch exceed the limit and create dangerous inconsistency.2025 CA Residential Code §R311.7.5.3

Behind exterior cement plaster (stucco) on a wood-framed wall, the code generally requires how many layers of an approved water-resistive barrier over the sheathing?

• a.No barrier is required
• b.One-half layer
• c.Two layers (equivalent) of water-resistive barrier✓
• d.Four layers

Because Portland cement plaster absorbs and holds water, the code generally requires two layers (or an equivalent) of water-resistive barrier behind stucco to protect the sheathing and framing. No barrier or a single half-layer is inadequate, and four layers is more than the code requires.2025 CA Residential Code §R703.7.3

Guards are required on a residential deck when the walking surface is located more than what height above the grade or surface below?

• a.12 inches
• b.18 inches
• c.24 inches
• d.30 inches✓

A guard is required where the deck walking surface is more than 30 inches above the grade or floor below, measured within a set horizontal distance. 12, 18, and 24 inches are all below the threshold that triggers a required guard.2025 CA Residential Code §R507.9

Under conventional framing rules, deep solid-sawn floor joists (such as nominal 2x10 or 2x12) generally require blocking or bridging installed at intervals not exceeding what maximum spacing?

• a.4 feet on center along the joist span
• b.8 feet on center along the joist span✓
• c.12 feet on center along the joist span
• d.No blocking is ever required for solid-sawn joists

Deep joists whose depth-to-thickness ratio exceeds about six can twist or buckle, so blocking or cross bridging is required at intervals no greater than 8 feet along the span. 4 feet is stricter than the code minimum; 12 feet exceeds the limit and would leave the joists poorly restrained; claiming blocking is never required ignores lateral-stability rules for tall members.2025 CA Residential Code §R502.7

In a wood-framed dwelling, fireblocking must be installed in concealed stud wall cavities at the ceiling and floor levels and, along the horizontal run, at intervals not exceeding what distance?

• a.4 feet
• b.6 feet
• c.10 feet✓
• d.20 feet

Fireblocking cuts off concealed draft openings so fire cannot spread quickly through wall cavities; horizontally it is required at intervals not exceeding 10 feet, plus at ceiling and floor levels. 4 and 6 feet are stricter than required, and 20 feet far exceeds the code limit, leaving an unbroken chimney-like cavity.2025 CA Residential Code §R302.11

When nailing wood structural panel subflooring or wall sheathing by hand, what is the typical fastener spacing required at the supported panel edges and at intermediate (field) supports?

• a.6 inches on center at edges and 12 inches on center in the field✓
• b.12 inches at edges and 24 inches in the field
• c.3 inches at edges and 6 inches in the field
• d.4 inches at edges and 8 inches in the field

Standard panel attachment calls for fasteners at 6 inches on center along supported edges and 12 inches on center at intermediate supports. 12/24 is too sparse and would not develop the panel's design capacity; 3/6 and 4/8 are the tighter patterns reserved for high-load shear walls, not ordinary sheathing.2025 CA Residential Code §R602.3

In conventional roof framing, collar ties (or ridge straps) used to resist wind uplift and keep the ridge from separating are generally installed in what part of the attic space?

• a.In the lower third, near the top of the exterior walls
• b.In the upper third of the attic, near the ridge✓
• c.At the exact mid-height of the rafters only
• d.Flat across the bottom of the ceiling joists

Collar ties resist ridge separation and uplift and are placed in the upper third of the attic height, connecting opposing rafters near the ridge. Placing them low near the walls describes rafter ties (a different member); mid-height only and flat at the ceiling misstate the required location for collar ties.2025 CA Residential Code §R802

A common rafter must span a horizontal run of 8 feet and rise a vertical height of 6 feet from the top plate to the ridge. Ignoring overhang, what is the approximate line length of the rafter?

• a.12 feet
• b.14 feet
• c.10 feet✓
• d.11 feet

The rafter is the hypotenuse of a right triangle: length equals the square root of (8 squared plus 6 squared) = square root of (64 + 36) = square root of 100 = 10 feet. This is the classic 3-4-5 triangle scaled by two. 12 and 14 feet overstate the diagonal, and 11 feet does not match the exact calculation.

At the ends of a wood-framed shear wall, a hold-down device anchored to the foundation is installed primarily to resist which force?

• a.Overturning and uplift at the wall ends during lateral loading✓
• b.Vertical dead load from the roof above
• c.In-plane sliding of the whole wall along the sill
• d.Thermal expansion of the wood framing

During earthquake or wind loading a shear wall tends to rotate, lifting one end; hold-downs anchor that end to the foundation to resist overturning and uplift. Gravity dead load is carried by studs and plates, sliding is resisted by anchor bolts, and thermal movement is not the function of a hold-down.2025 CA Residential Code §R602.10

For a conventional sill-plate anchor bolt set in a concrete foundation, what is the MINIMUM embedment depth of the bolt into the concrete?

• a.4 inches
• b.7 inches✓
• c.10 inches
• d.2 inches

Anchor bolts must extend at least 7 inches into the concrete or grouted masonry to develop adequate holding strength. 4 inches and 2 inches are too shallow to resist uplift and shear reliably, while 10 inches exceeds the minimum and is not the code-required figure.2025 CA Residential Code §R403.1.6

For a wood structural panel shear wall to develop its rated capacity, how must the panel edges be treated where sheets meet?

• a.Edges may be left unsupported as long as the field is nailed
• b.Only the top and bottom edges need backing
• c.All panel edges must be backed by framing or blocking and nailed✓
• d.Panels should be gapped and left unfastened at vertical joints

Shear is transferred through fastened panel edges, so every panel edge must bear on framing or blocking and be nailed at the required spacing. Leaving vertical edges unsupported or unfastened, or backing only top and bottom, breaks the load path and drastically reduces the wall's shear capacity.2025 CA Residential Code §R602.10

Exterior wood siding, sheathing, or trim that is NOT preservative-treated or naturally durable must generally be kept at least how far above exposed earth?

• a.6 inches above finished grade✓
• b.1 inch above finished grade
• c.Flush with grade is acceptable
• d.12 inches above finished grade

To limit decay, untreated wood must be kept a minimum of 6 inches above exposed earth. One inch and flush contact invite moisture wicking and rot, while 12 inches is a larger clearance than the code minimum and is not the required figure.2025 CA Residential Code §R317.1

On a wood-framed wall receiving exterior cement plaster (stucco), a weep screed must be installed at the base of the wall at a MINIMUM of how high above adjacent earth and above paved surfaces?

• a.2 inches above earth and 4 inches above paved areas
• b.4 inches above earth and 2 inches above paved areas✓
• c.1 inch above both earth and paved areas
• d.6 inches above earth and 6 inches above paved areas

The weep screed lets moisture drain out at the wall base and must sit at least 4 inches above earth and 2 inches above paved surfaces. Reversing the numbers, using 1 inch, or requiring 6 inches everywhere misstates the code minimums that balance drainage with splash protection.2025 CA Residential Code §R703.7.2.1

When metal lath is applied to a wood-framed wall to receive three-coat cement plaster, the lath fasteners should penetrate the framing members by at least approximately how much?

• a.1/8 inch
• b.1/4 inch
• c.3/4 inch✓
• d.No penetration into framing is needed if the sheathing holds the lath

Lath must be firmly anchored so the heavy plaster does not sag or crack; fasteners should penetrate the supporting framing by about 3/4 inch. Penetrations of 1/8 or 1/4 inch are too shallow to hold the load, and relying on sheathing alone without engaging framing leaves the lath inadequately secured.2025 CA Residential Code §R703.7

Where an exterior deck beam bears on a supporting post, what is the BEST practice for the beam-to-post connection?

• a.Toenail the beam to the top of the post
• b.Rely on gravity and the deck load to hold the beam in place
• c.Use a positive mechanical connection such as a post cap that ties beam to post✓
• d.Notch the post halfway and set the beam in the notch without fasteners

A positive mechanical connector (post cap or equivalent hardware) transfers load and resists lateral displacement and uplift between beam and post. Toenailing is weak and splits wood, gravity alone provides no uplift or lateral resistance, and an unfastened notched bearing can let the beam shift or roll off the post.2025 CA Residential Code §R507.5

How many board feet are contained in 15 framing members that are each nominal 2x10 and 16 feet long? (Board feet per piece = nominal thickness in inches times nominal width in inches times length in feet, divided by 12.)

• a.300 board feet
• b.350 board feet
• c.375 board feet
• d.400 board feet✓

Each piece = (2 x 10 x 16) / 12 = 320 / 12 = 26.67 board feet. Multiplied by 15 pieces = 400 board feet. The other choices result from dropping the piece count or mis-multiplying the thickness-width-length product.

Under the raised floor of a dwelling, short stud walls between the foundation and the first-floor framing (cripple walls) exceeding a nominal height must be braced primarily to resist what?

• a.Vertical settlement of the footing
• b.Lateral (seismic and wind) forces that could cause the walls to rack and the house to slide off✓
• c.Frost heave beneath the slab
• d.Termite entry at the mud sill

Cripple walls are a known weak point in earthquakes; when tall enough they must be braced with wood structural panels to resist lateral racking that can drop a house off its foundation. Settlement is a footing issue, frost heave concerns cold-climate slabs, and termite entry is addressed by other measures, not bracing.2025 CA Residential Code §R602.9

On a jobsite, prefabricated wood roof or floor trusses must NOT be treated in which of the following ways?

• a.Handled with spreader bars to avoid bending during a lift
• b.Braced permanently and temporarily as specified by the design
• c.Cut, notched, or drilled through chords or webs to run a duct, without the truss designer's approval✓
• d.Stored off the ground and kept from prolonged weather exposure

Truss members are engineered; cutting, notching, or drilling chords or webs without the designer's approval can void the design and cause collapse. Using spreader bars, following the specified bracing, and proper storage are all correct handling practices.2025 CA Residential Code §R502.11

A residential stairway must rise a total of 105 inches from finished floor to finished floor. Using the maximum allowable riser height of 7-3/4 inches, what is the MINIMUM number of risers, and the resulting even riser height?

• a.13 risers at about 8.08 inches each
• b.13 risers at about 7.75 inches each
• c.14 risers at 7.5 inches each✓
• d.12 risers at about 8.75 inches each

Divide 105 by the 7.75-inch maximum: 105 / 7.75 = 13.5, which rounds up to 14 risers because you cannot exceed the maximum. 105 / 14 = 7.5 inches per riser, within the limit. Thirteen risers would each be about 8.08 inches, exceeding the 7.75-inch cap; twelve risers at 8.75 inches also exceed the maximum.

On a stairway that turns using winder treads, what is the MINIMUM tread depth measured at the walk line, and the MINIMUM depth at any point of the narrow end?

• a.12 inches at the walk line and 8 inches at the narrow end
• b.10 inches at the walk line and 6 inches at the narrow end✓
• c.11 inches at the walk line and 10 inches at the narrow end
• d.7 inches at the walk line and 4 inches at the narrow end

Winder treads must provide at least 10 inches of depth at the walk line (typically 12 inches from the narrow side) and never less than 6 inches at any point. The other options either overstate the required depths or allow a dangerously narrow 4-inch section at the inside of the turn.2025 CA Residential Code §R311.7.5.2.1

On an open stair with a guard, the triangular opening formed by the tread, riser, and bottom rail is limited so that what size sphere cannot pass through?

• a.A 4-inch-diameter sphere
• b.A 5-inch-diameter sphere
• c.A 6-inch-diameter sphere✓
• d.An 8-inch-diameter sphere

For the special triangular opening at the tread, riser, and bottom guard rail, the code allows a slightly larger limit: a 6-inch sphere must not pass. The general 4-inch sphere applies to other guard openings, while 5- and 8-inch limits are not recognized values for this location.2025 CA Residential Code §R312.1.3

In conventional wall framing, where two members of a double top plate are spliced (joints occur), the upper and lower plate joints must be offset by at least how much?

• a.12 inches
• b.24 inches✓
• c.6 inches
• d.48 inches

Offsetting the top-plate joints at least 24 inches ties the wall together and keeps a continuous load path along the plate. A 12- or 6-inch offset leaves the splices too close and weak, while 48 inches is more than required and is not the specified minimum.2025 CA Residential Code §R602.3.2

Behind most exterior siding on a wood-framed wall, the code requires a water-resistive barrier equivalent to at least what?

• a.One layer of No. 15 asphalt felt or an approved equivalent✓
• b.Three layers of building paper
• c.A continuous rigid steel sheet
• d.No barrier as long as the siding laps are caulked

The minimum water-resistive barrier is one layer of No. 15 asphalt felt or an approved equivalent house wrap, lapped to shed water. Three layers exceed the general minimum, a steel sheet is not a required WRB, and caulked laps alone do not replace a continuous barrier behind the siding.2025 CA Residential Code §R703.2

A roof is designed with a 4:12 slope (4 inches of vertical rise for every 12 inches of horizontal run). If the horizontal run from the wall to the ridge is 15 feet, what is the total vertical rise?

• a.3 feet
• b.4 feet
• c.5 feet✓
• d.6 feet

Rise equals run times the slope ratio: 15 feet x (4/12) = 15 x 0.333 = 5 feet. The other answers come from applying the wrong ratio or misplacing the run and rise in the slope fraction.

When notching or boring a solid-sawn floor joist for a pipe, which limitation applies to protect the joist's strength?

• a.Notches may be any depth as long as they are on the top edge
• b.Notches at the ends may not exceed one-fourth of the joist depth, and notches are not permitted in the middle third of the span✓
• c.Bored holes may be located anywhere and up to half the joist depth
• d.A hole may be drilled within 1 inch of the joist edge

To keep bending strength, end notches are limited to one-fourth the joist depth and no notches are allowed in the middle third where bending stress peaks; bored holes are limited to one-third the depth and kept back from edges. Unlimited notch depth, half-depth holes anywhere, or drilling within an inch of the edge all weaken the joist beyond code limits.2025 CA Residential Code §R502.8.1

Fasteners and metal connectors that contact preservative (pressure) treated deck lumber must have what property to prevent premature failure?

• a.Corrosion resistance, such as hot-dipped galvanized or stainless steel✓
• b.The lowest possible cost regardless of coating
• c.A bright, uncoated bare-steel finish
• d.Aluminum contact directly against the treated wood

Modern treatment chemicals are corrosive to unprotected steel, so fasteners and connectors must be corrosion resistant, typically hot-dipped galvanized or stainless. Choosing by cost alone, using bare steel, or placing aluminum in direct contact all accelerate corrosion and can fail the connection.2025 CA Residential Code §R317.3

In braced-wall and shear-wall construction resisting seismic loads, anchor bolts at the sill plate are commonly required to have what added component for load transfer?

• a.A plastic sleeve around the bolt
• b.A thin fender washer only
• c.A steel plate washer (for example about 3 by 3 inches) between the nut and the sill plate✓
• d.No washer, because the nut alone is sufficient

A larger square steel plate washer spreads the clamping force and keeps the sill from splitting or pulling over the bolt head during shaking, improving lateral load transfer. A plastic sleeve does nothing structurally, a thin fender washer is undersized for shear walls, and omitting the washer lets the nut pull through the wood.2025 CA Residential Code §R602.11.1

A roof rises 3 inches for every 12 inches of horizontal run. Expressed as a percentage, what is the slope of this roof?

• a.25 percent✓
• b.33 percent
• c.3 percent
• d.12 percent

Percent slope equals rise divided by run times 100: (3 / 12) x 100 = 25 percent. Thirty-three percent would be a 4:12 slope, 3 percent and 12 percent come from misreading the rise-over-run ratio.