CSLB General Building (B) — All Questions

Efflorescence (white crystalline deposits) appears on a masonry wall that is scheduled to be painted. What is the BEST way to handle it before coating?

• a.Apply a glossy oil enamel to lock the crystals in place so the hard film holds them against the masonry
• b.Wet the wall thoroughly so the crystals dissolve into the surface and no deposits are left to brush off
• c.Paint directly over it with a thick latex topcoat to hide it, counting on the extra build to bury the white
• d.Dry-brush or otherwise remove the deposits and correct the moisture source before painting✓

Efflorescence is salt carried to the surface by moisture; it must be removed (dry brushing or masonry cleaner) and the underlying moisture problem addressed, or it will keep recurring and push paint off. Painting over it, wetting it, or sealing it with enamel does not stop the moisture and the coating will fail.

A painter must achieve a specified DRY film thickness. During application the coating is checked with a wet-film gauge. Why is the WET film reading higher than the target dry film thickness?

• a.Because solvent or water evaporates as the coating cures, leaving a thinner dry film✓
• b.Because primer adds thickness after topcoating, so the finished build ends up greater than what was measured wet
• c.Because the gauge is inaccurate on wet paint
• d.Because dry film always equals twice the wet film, so any wet reading is doubled when the coating cures

A coating shrinks as its solvent or water evaporates, so the dry film is thinner than the wet film. Knowing the percent solids lets the painter target a wet film that cures down to the specified dry thickness. The gauge is accurate, dry film is not double wet film, and primer does not increase topcoat thickness.

New portland-cement stucco or fresh concrete is highly alkaline. Applying an ordinary oil-based paint too soon can cause which specific failure?

• a.Excessive gloss and hardness of the film
• b.Permanent color darkening with no loss of adhesion, as the alkali is assumed to tint the pigment only
• c.Faster and stronger adhesion than on aged masonry
• d.Saponification, where the alkali attacks the oil binder and the paint softens or lifts✓

Fresh cementitious surfaces are strongly alkaline; the alkali reacts with the oil in oil-based paint (saponification), softening the film and causing peeling. The remedy is to let masonry cure (commonly about 28 days) or use an alkali-resistant primer. Alkali does not increase gloss, improve adhesion, or merely darken color.

Bare galvanized steel is to be painted. Which preparation gives the BEST long-term adhesion?

• a.Leave the shiny zinc surface untouched and topcoat immediately
• b.Clean off oils, then use an etching or bonding primer formulated for galvanized metal✓
• c.Sand only the visible rust spots and paint over the rest
• d.Apply an oil-based alkyd primer directly for a chemical bond

Zinc coatings resist paint adhesion and react with oil-based (alkyd) primers to cause saponification and peeling. Cleaning the surface and using an etching or self-etching primer made for galvanizing gives durable adhesion. Direct alkyd primer fails, a slick untouched surface sheds paint, and spot-sanding rust ignores the zinc adhesion problem.

An old, sound exterior paint film shows heavy chalking (a powdery residue on the surface). Before repainting, the MOST important prep step is to:

• a.Scuff-sand only, leaving the chalk in place for tooth so the new coat has something to grip
• b.Apply the new coat directly so the chalk bonds it tighter, treating the powder as part of the surface
• c.Wash and remove the chalk residue so the new coat can bond to a sound surface✓
• d.Add extra water to the new paint so it soaks into the chalk and carries binder down to sound material

Chalk is a loose powder from binder breakdown; a new coat applied over it bonds only to the powder and peels. Washing (and sometimes a bonding primer) removes the chalk so the new paint adheres to sound material. Painting over chalk, thinning to soak in, or leaving chalk as tooth all lead to poor adhesion.

Why do finish carpenters and painters often 'back-prime' exterior wood trim and siding before installation?

• a.To seal the back and edges so moisture absorption is balanced, reducing cupping and paint failure✓
• b.To add structural strength to the board so that it can span farther between its fasteners once it is installed
• c.To make the visible face glossier
• d.To eliminate the need for any face primer, since the coating on the back is taken to serve both faces of the board

Priming the concealed back and edges balances moisture movement into and out of the board, which reduces cupping, warping, and premature failure of the finish coat on the face. It does not change face gloss, replace the face primer, or add strength.

A room measures about 12 ft by 15 ft with 8 ft ceilings. Ignoring openings, the four walls total roughly 432 square feet. If one gallon of paint covers about 350 square feet per coat, how much paint is needed for TWO coats (rounded up to whole gallons)?

• a.3 gallons✓
• b.2 gallons
• c.5 gallons
• d.1 gallon

Two coats over 432 sq ft is 864 sq ft of coverage. Dividing by 350 sq ft per gallon gives about 2.47 gallons, which rounds up to 3 gallons. One or two gallons is too little for two coats and five gallons is far more than needed.

Cedar and redwood siding can bleed brownish stains through ordinary paint. Which primer choice BEST prevents this discoloration?

• a.A stain-blocking primer that seals the water-soluble tannins in the wood✓
• b.No primer, just extra topcoats, on the assumption that enough paint will cover the stain
• c.A high-gloss clear varnish
• d.A thinned latex topcoat used as its own primer

Cedar and redwood contain water-soluble tannins that migrate through latex paint and cause brown staining. A dedicated stain-blocking primer seals the tannins so they do not bleed through. Self-priming topcoats, no primer, or clear varnish do not lock in the tannins.

Before hanging vinyl wallcovering on new, primed drywall, why is a wallcovering primer/sizing typically applied?

• a.To make the wall permanently waterproof behind the vinyl wallcovering
• b.To provide a uniform, sealed surface with good adhesion and allow future strippability✓
• c.To eliminate the need to smooth the wall before the paper goes up
• d.To add a decorative color under the seams so joints are less visible

A wallcovering primer (sizing) seals the surface, evens out porosity for uniform adhesive grab, and lets the paper be stripped later without tearing the drywall face. It is not a decorative layer, does not replace surface prep, and does not make the wall waterproof.

A tile setter spreads thinset mortar but leaves it too long before placing tile, and a skin forms on the ridges. What is the MAIN risk of setting tile into skinned-over thinset?

• a.The mortar color will change but bond is unaffected, so the skin is only a cosmetic issue on the ridges
• b.Poor bond because the skinned surface no longer transfers adhesive to the tile✓
• c.The tile will set faster and stronger because the stiffened ridges grip the back of the tile sooner
• d.The grout joints will be wider because the stiff ridges hold each tile up off the mortar bed

Once thinset skins over (passes its open time), it can no longer wet out and grab the back of the tile, so bond strength drops and tiles can debond. The setter should remove the skinned mortar and re-spread fresh. It does not set stronger, does not widen joints, and the skin is a real bond problem, not just color.

An uncoupling (crack-isolation) membrane is installed between a concrete slab and ceramic tile. Its PRIMARY purpose is to:

• a.Serve as the finished wearing surface
• b.Allow minor in-plane movement of the slab without transferring cracks to the tile✓
• c.Add structural load capacity to the slab so that it can carry heavier loads once the tile is set over it
• d.Replace the need for any thinset mortar, since the membrane itself is taken to hold the tile in place

An uncoupling membrane separates the tile layer from slab movement so shrinkage or small cracks in the concrete are not telegraphed up through the tile and grout. It does not add structural capacity, still requires thinset above and below, and is a hidden layer, not the wear surface.

For a wet area like a shower, industry standards limit allowable framing/subfloor deflection so tile does not crack. A common maximum for ceramic tile is about L/360, but NATURAL STONE typically requires a stiffer floor of about:

• a.L/240
• b.L/180
• c.L/720✓
• d.L/300

Natural stone is more brittle and crack-prone than ceramic tile, so it needs a stiffer assembly, commonly limited to about L/720 deflection versus L/360 for ceramic. The looser limits (L/180, L/240, L/300) allow too much movement and can crack stone.

Interior tile floors need periodic movement (expansion) joints. Industry guidance commonly recommends interior movement joints roughly every ____, and MORE frequently for floors exposed to sunlight or moisture.

• a.Only at the room's exact center
• b.20 to 25 feet✓
• c.5 to 8 feet
• d.50 to 60 feet

Interior tile floors typically get movement joints about every 20 to 25 feet (and at changes of plane and abutting restraints), with tighter spacing (roughly 8 to 12 feet) where exposed to sun or moisture. Fifty-plus feet is too far apart, 5 to 8 feet is unnecessarily tight for typical interiors, and a single center joint ignores perimeter restraint.

A shower receptor will use a liquid-applied waterproofing membrane over the tile backer. The MOST important installer control for a reliable waterproof layer is to:

• a.Skip the corners since tile covers them
• b.Use the membrane only on the floor, not the walls, on the view that the water collects on the pan and never reaches the wall backer board
• c.Achieve the manufacturer's required wet/dry film thickness and full continuous coverage, especially at corners and the curb✓
• d.Apply a single thin coat as fast as possible

Liquid waterproofing works only when it forms a continuous film at the required thickness, with special attention (and often reinforcing fabric) at inside corners, changes of plane, and the curb where water collects. A single thin coat, skipped corners, or wall-less coverage leave gaps that leak.

A tile order calls for covering a floor of 240 square feet. The chosen tile comes in boxes that each cover 11 square feet. Adding about 10% for cuts and waste, how many full boxes should be ordered?

• a.20 boxes
• b.24 boxes✓
• c.30 boxes
• d.22 boxes

240 sq ft plus 10% waste is 264 sq ft. Dividing by 11 sq ft per box gives 24 boxes exactly. Twenty-two boxes covers only the bare area with no waste allowance, 20 is short, and 30 is far more than needed.

When setting translucent or moisture-sensitive natural stone (such as certain marbles), a WHITE, non-staining setting mortar is preferred over a gray latex thinset MAINLY because:

• a.Gray mortar has no bonding strength when it is used under a translucent stone
• b.White mortar cures faster in all conditions, so the stone can be grouted the same day
• c.White mortar eliminates the need for sealing the stone once the setting bed has dried
• d.Gray or moisture-carrying mortar can show through translucent stone or cause staining/discoloration✓

Light-colored and translucent stones can telegraph the dark color of gray mortar and are prone to staining from mortar moisture and pigments, so a white, low-moisture (often rapid-set) mortar is used. Cure speed, bonding, and the need to seal the stone are separate considerations.

In a commercial kitchen or a setting exposed to acids and constant washdown, which grout offers the BEST stain and chemical resistance?

• a.Ordinary sanded cement grout
• b.No grout at all
• c.Standard unsanded cement grout
• d.Epoxy grout✓

Epoxy grout resists chemicals, acids, and staining far better than cement grouts, making it the best choice for kitchens, labs, and heavy washdown areas. Sanded and unsanded cement grouts are porous and stain, and leaving joints ungrouted is never acceptable.

After grouting a tile wall, a light cloudy film remains on the tile faces. This grout haze is BEST removed by:

• a.Wiping/cleaning after the grout has firmed but before it fully hardens, then a haze remover if needed✓
• b.Aggressive dry sanding of every tile face until the cloudy film has been abraded off the glazed surface of each piece
• c.Leaving it because it disappears on its own within a year, as ordinary use and routine cleaning wear the thin film away
• d.Flooding the wall with water immediately after grouting so that the film is rinsed away before it can set on the tile

Grout haze is cleaned by wiping the tile once the grout has firmed in the joints but before it fully cures, using a damp sponge and, if needed, a grout haze remover. Waiting a year, dry sanding, or flooding fresh grout with water (which weakens and washes out the joints) are all wrong.

Before installing resilient flooring over a concrete slab, moisture is tested. In the anhydrous calcium chloride test (MVER), results are reported in:

• a.Pounds of moisture emitted per 1,000 square feet in 24 hours✓
• b.Percent slope of the slab measured across the area that will receive the flooring
• c.Degrees of surface temperature
• d.Pounds per square inch of compressive strength developed by the concrete slab

The calcium chloride test measures moisture vapor emission rate (MVER) in pounds per 1,000 square feet per 24 hours, which is compared to the flooring manufacturer's limit. Slope, temperature, and compressive strength are unrelated to that moisture measurement.

The in-situ relative humidity (RH) probe test (per ASTM F2170) is another way to check a concrete slab before flooring. Many resilient flooring manufacturers set an acceptable internal RH limit at about:

• a.10 to 15 percent
• b.50 percent exactly, never higher
• c.99 percent
• d.75 to 80 percent✓

In-situ RH probes commonly must read at or below roughly 75 to 80 percent (per the specific product) for resilient flooring to be installed safely. Ten to 15 percent is unrealistically dry, a flat 50 percent cap is stricter than most products require, and 99 percent is far too wet.

Before nailing down solid strip hardwood over a wood subfloor, an installer checks moisture content of BOTH the flooring and the subfloor. Best practice is to keep the difference between them within about:

• a.15 percentage points
• b.20 percentage points
• c.2 to 4 percentage points✓
• d.No limit; any difference is fine

Wood flooring guidance keeps flooring and subfloor moisture within roughly 2 to 4 percentage points (tighter for wide planks) so the boards do not shrink or cup after installation. Ignoring the difference or allowing 15 to 20 points guarantees gaps, cupping, or buckling.

At the doorway between a tile floor and a lower carpeted room, which transition piece is generally the BEST choice to bridge the height difference?

• a.A T-molding, which is for equal-height floors meeting at the same finished level across the doorway
• b.A reducer strip that tapers from the higher floor down to the lower one✓
• c.A stair nose molding
• d.A flush metal divider with no slope

A reducer strip is made to transition between two floors of different heights, tapering from the higher surface down to the lower one. A T-molding suits floors of equal height, a flush divider does not handle a height change, and a stair nose is for stair edges.

Stretch-in (tackless) carpet installation over cushion relies on gripper strips at the room perimeter. When placing those strips, the pins should point:

• a.Away from the wall toward the room center, facing the field
• b.Toward the wall, with a small gap between strip and wall to tuck the carpet✓
• c.It does not matter which way the pins face once nailed down
• d.Straight up toward the ceiling through the carpet backing

Tackless strip pins angle toward the wall so the stretched carpet hooks onto them and stays under tension, with a small gutter left to tuck the carpet edge. Pins facing up, facing the room, or in any direction would not hold the stretched carpet.

Solid strip hardwood is being blind-nailed. The fasteners are typically driven at roughly a 45-degree angle:

• a.Straight down through the face of each board, with the heads set and filled afterward
• b.Through the tongue so the next board hides the fastener✓
• c.Through the groove edge only, so the fastener passes through the lower lip of the joint
• d.Into the top surface at the center of each board, away from both the tongue and the groove

Blind-nailing drives fasteners at about 45 degrees through the tongue of each board so the adjacent board's groove conceals them, leaving a clean face with no visible nails. Face nailing, groove nailing, or center-face nailing would show fasteners or fail to lock the boards.

A moisture-sensitive engineered wood floor will be installed over a radiant-heated slab. To protect the flooring, the surface temperature of the floor is generally kept below about:

• a.150 degrees F
• b.There is no temperature concern with wood floors
• c.120 degrees F
• d.85 degrees F (per the flooring manufacturer)✓

Wood flooring manufacturers commonly cap radiant floor SURFACE temperature at around 80 to 85 degrees F so the wood does not dry out, gap, or crack. 120 or 150 degrees would damage the flooring, and wood floors are definitely temperature sensitive.

Before installing thin resilient flooring (such as luxury vinyl tile), the substrate flatness matters because the material is thin. A common flatness tolerance is no more than about 3/16 inch deviation in:

• a.1 foot
• b.100 feet
• c.50 feet
• d.10 feet✓

Resilient flooring guidance commonly requires flatness within about 3/16 inch in 10 feet (and 1/32 inch in 1 foot) so bumps and dips do not telegraph or cause failures. Measuring over 1 foot is too short for that tolerance, and 50 or 100 feet is meaninglessly long.

Under the North American Architectural Woodwork Standards, three quality grades are defined. Between Premium and Custom, which grade is typically the LOWEST/most economical, used where appearance requirements are minimal?

• a.Economy✓
• b.Premium
• c.Marine
• d.Custom

NAAWS defines Economy, Custom, and Premium grades; Economy is the lowest and is used where cost drives the work and appearance is not critical. Premium is the highest, Custom is the common default, and Marine is not a NAAWS grade.

A run of tall cabinets meets a wall that is not perfectly straight. To make the cabinet side fit tightly against the wavy wall, the finish carpenter should:

• a.Cut the wall studs to match the cabinet so the framing is brought into line with the cabinet side
• b.Scribe the cabinet side (or a filler) to the wall contour and trim to that line✓
• c.Force the cabinet against the wall and caulk the gaps so the joint looks closed once it is painted
• d.Leave a visible gap and cover it with a wide molding

Scribing transfers the wall's irregular contour onto the cabinet side or a filler strip, which is then trimmed to that line for a tight, gap-free fit. Forcing and caulking looks poor, cutting studs is not the fix, and a wide molding is a crude cover-up rather than a proper fit.

A stone countertop overhangs a base cabinet to form an eating bar. When the unsupported overhang exceeds roughly the material's safe limit (often about 10 to 12 inches for typical stone), the installer should:

• a.Rely on the adhesive to the cabinet alone
• b.Add corbels, brackets, or steel supports to carry the overhang✓
• c.Nothing; stone never needs added support because the slab is stiff enough to carry itself
• d.Make the overhang thinner by grinding

Beyond the material's safe cantilever, an unsupported stone overhang can crack or tip, so brackets, corbels, or hidden steel supports are added to carry the load. Adhesive alone is inadequate, grinding it thinner weakens it further, and stone overhangs frequently do need support.

Wall cabinets and grab-bar-ready walls rely on solid backing. When mounting heavy wall cabinets, the fasteners should be driven:

• a.Into the wall framing (studs) or solid blocking, not just drywall✓
• b.Into the cabinet face frame from inside only, not the wall
• c.Into the baseboard below the cabinet along the wall
• d.Into the drywall using plastic anchors only, spaced evenly

Heavy wall cabinets must be screwed through their hanging rail into the studs or solid blocking so the framing carries the load; drywall anchors alone will pull out. Fastening only to the face frame or the baseboard does not anchor the cabinet to the structure.

During cabinet installation, a narrow gap remains between the last cabinet and a side wall or an appliance. The clean, professional way to close that gap is to use:

• a.A piece of baseboard turned sideways to fill the opening with stock already on the job
• b.A strip of the countertop material cut down to width so the color matches the counter
• c.A matching filler (filler strip) scribed and cut to fit✓
• d.A bead of colored caulk only, tooled into the opening and left to bridge the gap

Cabinet lines are designed with filler strips to absorb dimensional gaps at walls and appliances; the filler is scribed and cut for a clean, matching fit. Caulk alone, countertop scraps, or sideways baseboard are improvised and look unprofessional.

Fire-rated gypsum board used to achieve a one-hour wall assembly is commonly Type X. Its typical nominal thickness is:

• a.1/2 inch
• b.3/8 inch
• c.5/8 inch✓
• d.1/4 inch

Type X gypsum board is typically 5/8 inch thick, with a glass-fiber-reinforced core that resists fire long enough for rated assemblies. 1/4 and 3/8 inch are thin/utility boards, and 1/2 inch is standard (non-Type X) wall board.

On long, continuous drywall walls and ceilings, control (expansion) joints are added to relieve stress. A common guideline places control joints in walls at a MAXIMUM spacing of about:

• a.8 feet
• b.They are never needed indoors
• c.30 feet✓
• d.100 feet

Gypsum board guidance commonly limits partition/wall control joint spacing to a maximum of about 30 feet (and about 50 feet on ceilings without perimeter relief, less otherwise) to control cracking from movement. Eight feet is unnecessarily close, 100 feet is far too long, and long runs do need control joints.

A wall that will receive a high-gloss enamel or be raked by strong sidelighting typically requires the highest drywall finish. Under the industry levels of gypsum finish, that is:

• a.Level 5✓
• b.Level 2
• c.Level 1
• d.Level 0

Level 5 finish adds a skim coat over the entire surface for the smoothest result, needed under gloss paints and critical (raking) lighting. Levels 0 to 2 are minimal finishes for concealed or utility surfaces and would show every imperfection under gloss or sidelight.

To reduce ceiling sag when a water-based spray texture will be applied, code and industry guidance generally require which gypsum board for ceilings framed 16 inches on center?

• a.3/8-inch board is required because the thinner sheet weighs less on the framing
• b.1/2-inch sag-resistant board, or 5/8-inch board✓
• c.No board thickness matters for texture because the joint compound carries the added weight
• d.1/4-inch board is fine

For 16-inch on-center ceiling framing that will get a water-based texture, standard 1/2-inch board can sag, so either 1/2-inch sag-resistant (interior ceiling) board or 5/8-inch board is used. Thin 1/4 or 3/8 boards sag badly, and thickness definitely matters when a wet texture adds weight.

Which combination of assembly changes will BEST raise the Sound Transmission Class (STC) of an interior partition?

• a.Adding cavity insulation, a second layer of gypsum, and decoupling one face with resilient channel✓
• b.Leaving the stud cavity empty and rigidly attaching both faces
• c.Using thinner drywall on both sides
• d.Sealing all cracks with rigid mortar and adding no insulation, so that the partition becomes one single solid mass

Sound isolation improves with added mass (second gypsum layer), absorption (cavity insulation), and decoupling (resilient channel) to break the vibration path. Thinner board, an empty rigidly attached cavity, or rigid connections lower STC by transmitting sound more directly.

On gypsum board joints, paper tape and mesh (self-adhesive fiberglass) tape behave differently. A key reason many finishers use PAPER tape at inside corners is that:

• a.Mesh tape is stronger than paper in every application and joint
• b.Paper tape has a crease and higher strength that resists cracking at corners✓
• c.Paper tape is only for exterior use and must not go indoors
• d.Paper tape needs no joint compound because it sticks on its own

Paper tape folds cleanly at its center crease and has higher tensile strength, making it preferred at inside corners where movement tends to crack joints; mesh is convenient on flats but weaker and more crack-prone at corners. Paper tape still needs compound, mesh is not universally stronger, and paper tape is an interior finishing product.

When installing a window in an exterior wall with a weather-resistive barrier, the flashing should be lapped so that:

• a.Only caulk is used, with no flashing, so a continuous bead around the window becomes the water seal
• b.All flashing is installed after the siding, laid over the finished wall where it can be seen and replaced
• c.Upper pieces lap over lower pieces (shingle fashion) so water drains outward✓
• d.The head flashing tucks behind the sill pan, so the sill piece is the outermost layer at the opening

Flashing must be shingle-lapped, with the sill pan first, jamb flashing over the sill, and head flashing lapping over the jambs and tucked under the upper WRB, so water always sheds down and out. Reversing the laps, flashing after siding, or relying on caulk alone traps water and causes leaks.2025 CA Residential Code §R703

A below-grade bedroom uses a window well to meet emergency escape requirements. The window well must generally provide a minimum horizontal area of at least ____, with a minimum projection and width of 36 inches.

• a.3 square feet
• b.1 square foot
• c.20 square feet
• d.9 square feet✓

Window wells for emergency escape openings generally must be at least 9 square feet with a minimum horizontal projection and width of 36 inches so an occupant can climb out. Three square feet and one square foot are far too small, and 20 square feet exceeds the required minimum.2025 CA Residential Code §R319

Glazing that is adjacent to a door and within a certain arc of the closed door edge generally must be safety glazing. That arc is measured within a ____ radius of the door in the closed position and up to 60 inches above the floor.

• a.48-inch
• b.24-inch✓
• c.12-inch
• d.72-inch

Glazing within a 24-inch arc of a door's vertical edge (in the closed position) and 60 inches above the floor is a hazardous location requiring safety glazing, because someone can strike it near the door. Twelve inches is too small, and 48 or 72 inches overstates the regulated zone.2025 CA Residential Code §R324

Glazing used in a guard or railing where people could fall against it must be:

• a.Ordinary annealed glass, since it is protected by the railing frame that surrounds the panel
• b.Wired glass for fire resistance only
• c.Safety glazing (tempered or laminated) able to resist the required loads✓
• d.Any glass thicker than 1/4 inch, on the view that added thickness alone resists the impact

Glazing that acts as, or is in, a guard where a fall is possible must be safety glazing capable of resisting the applied loads, so it will not shatter into dangerous shards or let someone fall through. Annealed glass, plain wired glass, or mere thickness do not meet the safety-glazing requirement.2025 CA Residential Code §R324

How can an installer verify that an installed pane is tempered (safety) glass?

• a.Tap it; tempered glass sounds hollow and rings differently from an annealed pane of the same size
• b.Tempered glass is always tinted blue
• c.Tempered glass is thinner than annealed glass
• d.Look for a permanent etched/sandblasted manufacturer's mark in a corner✓

Tempered glass carries a permanent identifying mark (etched or ceramic-fired) in a corner naming the maker and standard, which is the reliable field check. Tint color, thickness, and sound are not dependable indicators of tempering.

A fire-rated door assembly in a rated wall relies on several features to perform. Which is essential for the assembly to keep its rating in a fire?

• a.The door may be blocked open for convenience during the workday
• b.Any field-cut glazing size is allowed in the finished door
• c.The door must be self-closing (or automatic-closing) and positively latch✓
• d.The door needs no latch as long as it is heavy in its frame

A fire door must close and latch on its own so it actually seals the opening during a fire; a blocked-open or unlatched door defeats the rating, and vision panels are limited to tested/listed sizes. Weight is not a substitute for latching, and glazing cannot be enlarged beyond the listing.2025 CA Building Code §716

For an accessible door, operable hardware (lever, pull, or loop) must be usable without tight grasping, pinching, or twisting of the wrist, and mounted between 34 and 44 inches above the floor. Which hardware BEST meets this?

• a.A lever handle✓
• b.A round doorknob requiring twisting
• c.A small key-only latch
• d.A thumb-turn requiring pinching

Lever hardware operates with a push and no wrist twisting, meeting accessibility requirements; round knobs, thumb-turns, and pinch latches all require grasping, twisting, or pinching and are not accessible. Mounting height still applies to the chosen lever.2025 CA Building Code §11B-404.2.7

At an accessible door threshold, the maximum height for a new threshold is generally:

• a.1 inch
• b.1-1/2 inches
• c.2 inches
• d.1/2 inch✓

Accessible thresholds at doorways are generally limited to a maximum of 1/2 inch (with any portion above 1/4 inch beveled) so wheelchairs and people who shuffle can cross safely. One inch, 1-1/2 inches, and 2 inches are trip and rolling barriers that exceed the limit.2025 CA Building Code §11B

Under the California Energy Code prescriptive requirements, residential windows must not exceed a maximum U-factor. A lower U-factor and a low SHGC together mean the window:

• a.Provides less insulation value, letting heat pass through the glass more easily in either direction
• b.Insulates well and limits solar heat gain, improving energy performance✓
• c.Lets in more unwanted summer heat through the glazing, adding to the cooling load of the house
• d.Loses heat faster in winter, so the heating system has to replace what escapes through the window

A low U-factor means better resistance to heat flow (good insulation) and a low SHGC means less solar heat admitted, so together they cut both winter heat loss and summer heat gain. Providing less insulation value is what a high U-factor does; letting in more unwanted summer heat is what a high SHGC does; and losing heat faster in winter is again the high U-factor result. All three describe the opposite of this window.2025 CA Energy Code

A room's window area is being checked for natural light. A common code benchmark for required glazing (natural light) in a habitable room is a glazed area of at least ____ of the floor area of the room.

• a.8 percent✓
• b.1 percent
• c.25 percent
• d.50 percent

Habitable rooms typically must have glazing (for natural light) equal to at least 8 percent of the floor area, with about half of that openable for ventilation, unless mechanical/artificial systems are provided. Twenty-five and 50 percent are far above the minimum, and 1 percent is far too little.

A window unit has a glazed opening 4 feet wide by 5 feet tall in a room with 250 square feet of floor area. If the light requirement is 8 percent of floor area, does this single window meet it?

• a.No; it provides only about 10 square feet of glazing, which falls short of the light requirement
• b.Yes; only 5 square feet is required
• c.Yes; 20 square feet of glazing meets the 20-square-foot requirement✓
• d.No; 8 percent of 250 is 40 square feet, which is more glazing than this one window supplies

The window glazing is 4 x 5 = 20 square feet, and 8 percent of 250 square feet is 20 square feet, so the single window exactly meets the natural light requirement. The window provides 20 (not 10) square feet, 8 percent of 250 is 20 (not 40), and the requirement is 20 (not 5) square feet.

When installing a skylight on a sloped roof, the head and side flashing should be integrated with the roofing so that:

• a.Only sealant seals the skylight to the deck
• b.The curb is set directly on the roofing felt with no flashing, with the shingles brought up tight against its sides
• c.The flashing sits on top of the finished roofing at the head
• d.Water sheds over the flashing and down the roof, with step/counter flashing lapped shingle-style✓

Skylight flashing must be woven into the roofing shingle-style, with head flashing under the upper courses and step/side flashing lapped so water always runs over the flashing and down-slope. Flashing over the head roofing, sealant only, or a bare curb all invite leaks.

Batt insulation is installed in a 2x6 wall cavity behind drywall. To achieve its rated R-value, the batt must be:

• a.Left with large gaps around wiring and boxes for airflow in the cavity
• b.Compressed tightly to fit any thickness of stud cavity behind the drywall
• c.Stapled only at the very top so it hangs freely down the stud cavity
• d.Installed at full loft, cut and fitted around obstructions without compression or voids✓

Insulation performs at its rated R-value only when installed to full thickness (loft) and carefully fitted around wiring, boxes, and pipes without compression or gaps. Compressing it lowers R-value, gaps create thermal bypass, and loose hanging leaves voids and sagging.2025 CA Energy Code