NASCLA Commercial General Building Practice Test

Free practice for the NASCLA Commercial General Building Exam. Tap an answer to see if you are right, why, and which code section to look up.

Questions are checked against public sources. They are not yet reviewed by a licensed professional.

About the exam

Code edition: IBC 2021 (section numbers; the bulletin also allows the 2024 IBC), 29 CFR 1926 (OSHA construction, in force 2026) and general construction practice

Commercial General Building

115

questions (115 scored)

5 h 30 min

time

70%

to pass

Open book

Free practice questions

Question 1

In a critical path method (CPM) schedule, what is the critical path?

Question 2

At what depth does OSHA generally require a protective system (sloping, shoring or a shield) in an excavation that is not entirely in stable rock?

Question 3

Which factor has the greatest effect on the strength of hardened concrete?

Question 4

What are the actual dimensions of a standard 8 x 8 x 16 concrete masonry unit (CMU)?

Question 5

What does the designation W14x90 tell you about a steel beam?

Question 6

What are the actual dressed dimensions of a nominal 2x10?

Question 7

In roofing, what is a "square"?

Question 8

A fire door assembly has a label. What must happen if the door, frame or hardware is altered in the field (for example, by cutting a new hole for hardware)?

Question 9

What is Type X gypsum board?

Question 10

One ton of refrigeration (air-conditioning capacity) equals how many Btu per hour?

Question 11

On a construction site, what protection does OSHA require for 120-volt, single-phase, 15- and 20-ampere receptacle outlets that are not part of the permanent wiring?

Question 12

What is an addendum during the bidding period?

Question 13

Calculation

An activity has an early start of day 12, a late start of day 18 and a duration of 5 days. What is its total float?

Question 14

In a trench 4 feet or more deep, what is the maximum lateral travel distance to a stairway, ladder, ramp or other safe means of egress?

Question 15

What does a slump test measure in fresh concrete?

Question 16

Calculation

Using 1.125 standard 8 x 16 blocks per square foot of wall (given), how many blocks are needed for a wall 80 ft long and 12 ft high with no openings, before waste?

Question 17

Calculation

Fourteen W12x26 beams are each 30 ft long. What is their total weight in tons (2,000 lb per ton)?

Question 18

Calculation

How many board feet are in one 2x6 that is 12 ft long?

Question 19

Calculation

A low-slope roof measures 120 ft by 85 ft. How many squares of membrane is that, before waste and laps?

Question 20

Which features are generally required on a swinging fire door?

Calculation practice

Generated problems with worked solutions, the part most candidates fail.

Practice by topic

General requirements

Questions: 91 · Often missed

Site construction

Questions: 49 · Often missed

Concrete

Questions: 35 · Often missed

Thermal & moisture protection

Questions: 30

Doors, windows & glazing

Questions: 22

Finishes

Questions: 24

Mechanical & plumbing systems

Questions: 24

Electrical systems

Questions: 20

Procurement & contracting requirements

Questions: 81 · Often missed

Exam rules

Real test (PSI candidate bulletin, updated July 2026): 115 scored questions plus 10 unscored pretest questions, 330 minutes, 81 correct (about 70%) to pass. This practice exam uses the 115 scored questions.

Open book: bring the bound references the bulletin lists (IBC 2021 or 2024, 29 CFR 1926, Gould's Construction Project Management and others); permanent tabs and highlighting are allowed. A silent, non-programmable calculator is allowed.

Code questions cite section numbers only; open your own code book to the section. Calculation questions give every value you need.

The NASCLA exam replaces the trade portion only. Your state still requires its own business & law exam, which is a separate test.

Whether the real test is offered in Spanish is not confirmed.

Unofficial practice; not affiliated with NASCLA, PSI or any licensing board.

Frequently asked questions

How is the NASCLA Commercial General Building Exam structured?

It has Commercial General Building (115 questions, 5 h 30 min, 70%). You need to pass each part.

Is the exam open book?

Yes. You may bring the IBC 2021 (section numbers; the bulletin also allows the 2024 IBC), 29 CFR 1926 (OSHA construction, in force 2026) and general construction practice code book, so this practice cites the section to look up instead of quoting it.

Can I take the exam in Spanish?

Some exams are offered in Spanish; check your candidate bulletin. Every question here is available in Spanish too.

Are these the real exam questions?

No. SkillPermit Pro is an independent study tool. Questions are written in our own words; they are not taken from the exam and are not endorsed by any licensing agency or testing vendor.

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Not affiliated with any state agency, TDLR, PSI, NFPA, EPA or CSLB. NEC® and National Electrical Code® are registered trademarks of NFPA.

Practice questions are written in our own words and cite code sections by number. Always study from your own copy of the code and the official candidate bulletin.

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