NASCLA Commercial General Building Contractor Exam — All Questions

A candidate passes the NASCLA Accredited Commercial General Building Contractor examination. What does passing it accomplish toward licensure?

• a.It grants a contractor license automatically in every accepting state
• b.It satisfies both the trade and the business/law requirements in one exam
• c.It satisfies the trade/technical portion in accepting states; each state's business and law licensing requirements still apply separately✓
• d.It replaces the need for any state license

The NASCLA Accredited exam covers the commercial building trade/technical knowledge and is accepted for that portion by roughly 18 jurisdictions. It does not license the candidate by itself: each state's separate business and law exam, financial, and application requirements still apply.NASCLA Accredited Program scope

On a competitively bid commercial project, what does a bid bond protect, and whom does it protect?

• a.It protects the owner if the low bidder refuses to enter the contract, by covering the difference to the next bidder up to the bond amount✓
• b.It protects the contractor's employees for on-the-job injuries
• c.It guarantees subcontractors and suppliers will be paid
• d.It protects the surety against the owner

A bid bond protects the owner: if the successful low bidder backs out, the surety covers the owner's added cost (typically the difference to the next bidder) up to the bond's penal sum. A payment bond protects subs and suppliers; a performance bond assures completion.Bid bond (surety three-party guarantee)

A general contractor stops paying its subcontractors on a bonded public project. Which bond gives the unpaid subs a remedy?

• a.The bid bond
• b.The maintenance bond
• c.The performance bond
• d.The payment bond✓

The payment bond guarantees that subcontractors and suppliers are paid, so it is the unpaid subs' remedy. The performance bond assures the owner the work is completed; the bid bond addresses a bidder backing out. Each of the three bonds protects a different party.Payment bond vs. performance bond (AIA A312)

During construction the owner directs a change that adds scope. What document formally modifies the contract sum and time for that change?

• a.A submittal
• b.A change order signed by the owner and contractor✓
• c.A daily field report
• d.A certificate of substantial completion

A change order is the written, signed agreement that modifies the contract's scope, price, and/or time. Performing extra work without a signed change order risks non-payment, so contractors document changes before proceeding whenever possible.Change order (contract modification)

An owner withholds 10% from each progress payment on a commercial project. What is the primary purpose of this retainage?

• a.To give the owner leverage and security that the contractor will complete the work and correct deficiencies✓
• b.To pay the architect's design fee
• c.To fund the contractor's payroll taxes
• d.To cover the building permit cost

Retainage is a percentage withheld from each progress payment and released after completion. It protects the owner by giving the contractor a financial incentive to finish and to correct punch-list items before the withheld money is paid.Retainage on progress payments

A change to the bidding documents is issued to all bidders before bids are submitted. What is this document called?

• a.A change order
• b.A submittal
• c.An addendum✓
• d.A punch list

An addendum modifies the bidding documents before bids are opened and is issued to all bidders so everyone prices the same scope. A change order, by contrast, modifies the contract after it is signed. Confusing the two is a common exam trap.Contract documents / addenda vs. modifications

In the CSI MasterFormat used to organize commercial specifications, what does Division 01 cover?

• a.Concrete
• b.Electrical
• c.Finishes
• d.General Requirements, such as administrative, procedural, and temporary-facility provisions✓

Division 01, General Requirements, covers the administrative and procedural provisions that apply across the whole project, such as submittals, temporary facilities, quality control, and closeout. The trade-specific work is in later divisions (for example, concrete, masonry, metals).CSI MasterFormat Division 01

Before fabricating and installing structural steel, the contractor sends detailed shop drawings to the architect/engineer for review. What is the purpose of this submittal process?

• a.To confirm the contractor's proposed materials and fabrication conform to the design intent before the work is built✓
• b.To request additional payment
• c.To close out the project
• d.To report a jobsite injury

Submittals such as shop drawings, product data, and samples let the design team verify that what the contractor intends to furnish matches the design intent before it is fabricated or installed. Catching a conflict on paper is far cheaper than tearing out built work.Submittals / shop drawings

In a critical path method (CPM) schedule, the critical path is the path that:

• a.has the most float and the most flexibility
• b.has the longest total duration and zero float, setting the shortest possible project completion time✓
• c.has the shortest total duration
• d.contains the most expensive activities

The critical path is the longest chain of dependent activities and has zero float. Because no path is longer, it fixes the earliest the project can finish, and any delay to a critical activity delays the whole project day for day.CPM scheduling (critical path)

OSHA requires a 'competent person' for certain operations such as excavation and scaffolding. A competent person must be able to identify hazards AND:

• a.hold a professional engineer license
• b.have at least ten years of experience
• c.have the authority to take prompt corrective action to eliminate the hazards✓
• d.be a full-time safety officer

Under 29 CFR 1926.32(f), a competent person can identify existing and predictable hazards and is authorized to take prompt corrective measures to eliminate them. Both the ability to spot the hazard and the authority to stop or correct the work are required.29 CFR 1926.32(f) (competent person)

A commercial project reaches the point where the owner can occupy and use it for its intended purpose, though minor items remain. What milestone is this, and what lists the remaining items?

• a.Notice to proceed; a submittal log
• b.Groundbreaking; a change order log
• c.Final completion; an addendum
• d.Substantial completion; a punch list✓

Substantial completion is when the work is sufficiently complete for the owner to occupy and use the project for its intended purpose. The remaining minor corrections are captured on a punch list, which the contractor completes before final payment and final completion.Substantial completion / punch list

Under OSHA's excavation standard, a protective system (sloping, shoring, or shielding) is generally required for a trench at what depth in soil other than stable rock?

• a.5 feet or deeper✓
• b.3 feet or deeper
• c.8 feet or deeper
• d.12 feet or deeper

OSHA's excavation standard (29 CFR 1926 Subpart P) requires a protective system for trenches 5 feet or deeper unless the excavation is entirely in stable rock. For trenches 20 feet or deeper, the protective system must be designed by a registered professional engineer.29 CFR 1926 Subpart P (excavations)

In OSHA's soil classification for excavation safety, which soil type is the most stable and which is the least stable?

• a.Type C is most stable; stable rock is least stable
• b.Stable rock is most stable; Type C is least stable✓
• c.Type A is least stable; Type C is most stable
• d.All soil types are equally stable

OSHA ranks excavation stability from stable rock (most stable) through Type A, Type B, to Type C (least stable). The flatter sloping and stronger protective systems are required as soils get less stable, so correctly classifying the soil drives the protective design.29 CFR 1926 Subpart P (soil classification)

Before placing a slab-on-grade, an engineer specifies that structural fill be compacted to 95% of maximum dry density. Which test establishes that maximum dry density reference?

• a.A slump test
• b.A concrete cylinder break test
• c.A Proctor compaction test✓
• d.A hydrostatic pressure test

The Proctor test (standard or modified) establishes a soil's maximum dry density and optimum moisture content in the lab. Field density tests then compare the compacted fill to that reference, so specifying '95% compaction' is meaningless without a Proctor value to measure against.Soil compaction / Proctor test

How many cubic yards of concrete are needed for a slab 20 ft by 30 ft placed 6 inches thick (before any waste factor)?

• a.3.7 cy
• b.11.1 cy✓
• c.22.2 cy
• d.100 cy

Convert thickness to feet (6 / 12 = 0.5 ft), then volume = (20 x 30 x 0.5) / 27 = 300 / 27 = 11.1 cubic yards. There are 27 cubic feet in a cubic yard, so dividing by 27 converts cubic feet to cubic yards.Concrete volume: (L x W x thickness) / 27

On a commercial pour, the crew measures the concrete's slump before placement. What does the slump test primarily indicate?

• a.The compressive strength at 28 days
• b.The air-entrainment percentage
• c.The chloride-ion content
• d.The consistency and workability (relative fluidity) of the fresh concrete✓

The slump test measures the consistency and workability of fresh concrete. It does not measure strength, which is verified by breaking cured cylinders (typically at 28 days per ACI 318). A slump outside the specified range signals a mix or water problem before the concrete is placed.ACI 318 / concrete slump test

Structural steel members on a commercial frame are most commonly connected in the field by which two methods?

• a.High-strength bolting and welding✓
• b.Wood screws and construction adhesive
• c.Mortar and grout
• d.Rivets and duct tape

Modern structural steel is joined chiefly by high-strength bolting and welding. Field bolting is fast and inspectable; welding provides continuous connections. Riveting, once common, is now largely obsolete for new commercial steel.Structural steel connections (AISC)

A commercial building's potable water system connects to an irrigation system. What device prevents contaminated water from being drawn back into the potable supply?

• a.A pressure-reducing valve
• b.A floor drain
• c.A backflow preventer✓
• d.A cleanout

A backflow preventer stops non-potable or contaminated water from siphoning or being pushed back into the potable water supply when pressure drops or reverses. Cross-connections like irrigation tie-ins are exactly where codes require backflow protection.Plumbing: backflow prevention

A framing plan calls for '2x4' studs. What is the actual dressed (surfaced) dimension of a nominal 2x4?

• a.Exactly 2 inches by 4 inches
• b.1-1/2 inches by 3-1/2 inches✓
• c.1 inch by 3 inches
• d.2-1/2 inches by 4-1/2 inches

A nominal 2x4 actually measures 1-1/2 inches by 3-1/2 inches after being surfaced (dressed). Nominal sizes are the rough-sawn dimension; estimators and framers must use the actual dimensions for layout, spacing, and material takeoffs.Nominal vs. actual lumber dimensions

At the intersection of a roof and a vertical wall or penetration, what component is installed to prevent water intrusion?

• a.A vapor retarder only
• b.A control joint
• c.A weep screed
• d.Flashing✓

Flashing is the sheet material installed at roof-to-wall junctions, penetrations, and other transitions to direct water away and prevent leaks. It is one of the most failure-prone areas of the building envelope, so correct flashing detailing is critical to thermal and moisture protection.Roofing / flashing (thermal and moisture protection)

A wall is scheduled to receive gypsum board with a smooth painted finish under critical lighting. Which describes the correct sequence of finishing the board?

• a.Tape the joints, then apply successive coats of joint compound and sand to a smooth, uniform surface before priming and painting✓
• b.Paint the board first, then tape the joints
• c.Leave the joints untaped because paint will hide them
• d.Apply mortar to the joints

Gypsum board joints are taped and then covered with successive coats of joint compound, each sanded smooth, to produce a flat surface. Higher finish levels (needed under critical lighting) require more coats and careful sanding, followed by priming before the finish paint.Gypsum board finish levels (finishes)

Among the common ASTM C270 mortar types, which is the highest-strength mortar, typically used where greater compressive and lateral strength is required (such as below grade)?

• a.Type O
• b.Type N
• c.Type M✓
• d.Type K

Of the standard mortar types (M, S, N, O), Type M has the highest compressive strength and is used where high strength is needed, such as below-grade or load-bearing foundation masonry. Type N is a common general-purpose mortar; Type O is a low-strength interior mortar.Masonry mortar types (ASTM C270)

Building codes require safety glazing (such as tempered or laminated glass) in certain 'hazardous locations.' Which location is a typical example?

• a.A window 6 feet above the floor in a corridor
• b.Glazing in a door and in panels adjacent to a door where human impact is likely✓
• c.A skylight over an unoccupied mechanical room only
• d.Only stained-glass windows

Codes (for example, the IBC) require safety glazing in hazardous locations where human impact is likely, such as in doors, sidelites next to doors, and glazing near walking surfaces and wet areas. Safety glazing breaks safely (tempered) or holds together (laminated) to reduce laceration injuries.IBC safety glazing (hazardous locations)

On a construction site, what is the primary purpose of ground-fault circuit-interrupter (GFCI) protection on temporary power?

• a.To increase the voltage delivered to tools
• b.To prevent overloading the generator
• c.To reduce the amperage drawn by motors
• d.To quickly interrupt the circuit when it senses a ground fault, protecting workers from electric shock✓

A GFCI monitors the current going out and returning; if it detects an imbalance (a ground fault, such as current flowing through a person), it trips quickly to prevent electrocution. OSHA requires GFCI protection (or an assured equipment grounding conductor program) for temporary construction power.GFCI protection (NEC / OSHA 1926.404)