NC Residential Exam Study Guide (2026)
Everything the North Carolina Residential Contractor Exam tests, topic by topic: what each section covers, the facts that come up most, and how to study it. Pair it with the free 15-question practice test.
The exam at a glance
| Questions | 90 trade questions + 40-question Business & Law section |
|---|---|
| Time | 210 minutes (trade) + 90 minutes (Business & Law) |
| Passing score | 70% on each part (63 of 90 on the trade exam) |
| Format | Open book (approved references, including the NC Residential Code) |
| Licensing body | NC Licensing Board for General Contractors (NCLBGC) |
| Test provider | PSI |
Mind map: the whole exam on one screen
1. Foundations and Slabs
This topic covers footings, anchorage, grading and concrete slabs under Chapters 4 and 5 of the NC Residential Code. The 2018 NC Residential Code is still the code in force while the 2024 edition remains delayed, so use 2018 values. Expect direct lookup questions with a single number as the answer.
Key facts
- Exterior footings must extend below the frost line, and never less than 12 inches below finished grade. The NC frost line depth is 12 inches (NCRC R403.1.4, Table R301.2(1)).
- Spread footings must be at least 6 inches thick, with projections of at least 2 inches that do not exceed the footing thickness (NCRC R403.1.1).
- Sill plates need 1/2-inch anchor bolts at 6 feet on center maximum, embedded at least 7 inches, with at least two bolts per plate and one within 12 inches of each corner (NCRC R403.1.6).
- The grade must fall at least 6 inches within the first 10 feet away from the foundation (NCRC R401.3).
- Foundation walls must extend at least 4 inches above finished grade where masonry veneer is used and 6 inches elsewhere (NCRC R404.1.6).
- Slabs on ground must be at least 3-1/2 inches thick over a 6-mil vapor retarder with joints lapped at least 6 inches (NCRC R506.1, R506.2.3).
- NC is a moderate weathering area, so porches, carport slabs, steps and garage floors need 3,000 psi air-entrained concrete; other foundation concrete needs 2,500 psi (NCRC Table R402.2).
Flashcards
Exam tip: Read whether the question asks for the footing depth, the footing thickness or the projection, because all three are small numbers in the same section.
2. Floor and Wall Framing
This topic covers joist bearing, notching and boring, top plates and stud cutting under Chapters 5 and 6. These rules protect the structure when trades cut members for pipes and wires. Questions often give a member size and ask for the largest allowed notch or hole.
Key facts
- Joists, beams and girders need at least 1-1/2 inches of bearing on wood or metal and 3 inches on masonry or concrete (NCRC R502.6).
- Notches in sawn joists and rafters may not exceed one-sixth of the member depth and may not sit in the middle third of the span. End notches may be up to one-fourth of the depth (NCRC R502.8.1).
- Bored holes in sawn joists may not exceed one-third of the member depth and must be at least 2 inches from the top, bottom or another hole (NCRC R502.8.1).
- Studs in exterior walls or bearing partitions may be notched up to 25 percent of their width. Nonbearing studs may be notched up to 40 percent (NCRC R602.6).
- Notching is not allowed in the bottom or top 6 inches of bearing studs (NCRC R602.6).
- End joints in double top plates must be offset at least 24 inches (NCRC R602.3.2).
- If a top plate is cut more than 50 percent of its width, a 16-gauge, 1-1/2-inch-wide metal tie must extend at least 6 inches past each side of the opening (NCRC R602.6.1).
Flashcards
Exam tip: Watch for bearing versus nonbearing walls: 25 percent and 40 percent are both listed in R602.6 and the wrong one is always an answer choice.
3. Stairs, Guards and Egress
This topic covers stair geometry, handrails, guards, egress doors and escape windows in Section R310 to R312. North Carolina amends the national code here, so values differ from the IRC. This is one of the most heavily tested areas.
Key facts
- Maximum riser height is 8-1/4 inches and minimum tread depth is 9 inches. The national IRC uses 7-3/4 and 10 (NCRC R311.7.5.1, R311.7.5.2).
- Within a flight, the largest riser or tread may not exceed the smallest by more than 3/8 inch (NCRC R311.7.5.1, R311.7.5.2).
- Stairs must be at least 36 inches wide and have at least 6 feet 8 inches of headroom. A flight may rise no more than 12 feet 3 inches between landings (NCRC R311.7.1, R311.7.2, R311.7.6).
- Handrails are required on at least one side of a flight with four or more risers, at 34 to 38 inches above the tread nosings (NCRC R311.7.8, R311.7.8.1).
- Guards are required where a walking surface is more than 30 inches above the floor or grade. They must be at least 36 inches high, or 34 inches on the open side of stairs, with openings that stop a 4-inch sphere (NCRC R312.1).
- Escape and rescue openings need 4 square feet of net clear opening, 22 inches clear height, 20 inches clear width and a sill no higher than 44 inches (NCRC R310.2.1, R310.2.2).
- The required exterior egress door must be side-hinged with at least 32 inches clear width and 78 inches clear height (NCRC R311.2).
Flashcards
Exam tip: If you remember the national IRC values of 7-3/4 inch risers or 5.7 square foot openings, do not pick them: NC uses 8-1/4 inches and 4 square feet.
Test yourself on these topics
Take the free 15-question NC Residential test, then save your results to unlock your Readiness Score and the mistakes bank.
4. Roofing and Attic Ventilation
This topic covers asphalt shingle rules, re-roofing limits, attic ventilation and attic access in Chapters 8 and 9. Expect ratio and slope questions. NC changed several items, including drip edge and attic access.
Key facts
- Asphalt shingles are allowed only on slopes of 2:12 or greater. Slopes from 2:12 up to 4:12 need double underlayment (NCRC R905.2.2).
- Shingles need at least four fasteners per strip shingle, or the manufacturer's number if higher. Nails must penetrate 3/4 inch into the sheathing or through it (NCRC R905.2.5, R905.2.6).
Flashcards
Exam tip: For vent area problems, convert square feet of attic to square inches only at the end: divide the attic area by 150 or 300 first, then multiply by 144 if the answer is in square inches.
5. Crawl Spaces and Moisture
This topic covers vented crawl spaces, decay protection, dampproofing and foundation drains. NC has its own crawl space section, R408, and these numbers differ from the national code. Moisture questions also reach into wall flashing and water-resistive barriers.
Key facts
- Crawl space vents must provide 1 square foot of net area for each 150 square feet of crawl space. This may drop to 1/1,500 with a ground vapor retarder and cross ventilation (NCRC R408.1.1).
- One foundation vent must be within 3 feet of each corner of the building (NCRC R408.1.2).
Flashcards
Exam tip: Do not mix up the two vapor retarder laps: 12 inches in a crawl space (R408.2) and 6 inches under a slab (R506.2.3).
6. Fire Separation and Alarms
This topic covers dwelling and garage separation, two-family and townhouse walls, draftstopping, and smoke and CO alarm placement in Sections R302, R314 and R315. These are life safety rules, and the exam likes exact material thicknesses and locations.
Key facts
- Openings from a garage directly into a sleeping room are not allowed. Other garage doors must be 1-3/8-inch solid wood, 1-3/8-inch solid or honeycomb steel, or 20-minute fire-rated (NCRC R302.5.1).
- The garage must be separated from the house and attic by at least 1/2-inch gypsum board on the garage side, and from habitable rooms above by 5/8-inch Type X gypsum board (NCRC Table R302.6).
Flashcards
Exam tip: Garage questions often hide the word bedroom: if the door opens into a sleeping room, the answer is that no door is allowed at all.
7. Residential Construction Practices
This topic covers practical field rules for masonry veneer, flashing, fireplaces and chimneys, and room sizes. These questions test whether you can find a specific install detail quickly in Chapters 3, 7 and 10.
Key facts
- Brick veneer ties must each support no more than 2.67 square feet of wall, spaced at most 32 inches horizontally and 24 inches vertically (NCRC R703.8.4.1).
- Veneer weep holes must be at most 48 inches on center, at least 3/16 inch in diameter, and located just above the flashing (NCRC R703.8.6).
Flashcards
Exam tip: The 3-2-10 chimney rule shows up as a word problem: check both the 3 foot and the 2 foot within 10 feet test, and the taller result controls.
8. Estimating and Plan Reading
This topic covers quantity takeoffs for concrete, roofing, framing and stairs, plus reading scaled drawings. Most of these questions are math, so set up the units carefully. The code supplies the limits, such as maximum riser height, that you plug into the math.
Key facts
- Concrete volume: length x width x depth in feet gives cubic feet. Divide by 27 to get cubic yards.
- Convert inches to feet before multiplying. A 4-inch slab is 4/12 or 0.333 foot thick.
Flashcards
Exam tip: Most wrong answers come from forgetting to convert inches to feet or forgetting to divide by 27, so check your units before picking a choice.
9. NC Business and Law
This topic covers who needs a general contractor license, license limits and renewal, continuing education, liens and prompt payment. It is a separate 40-question part with its own 70 percent pass mark. Answers come from NC General Statutes Chapters 87, 44A, 22C and 97.
Key facts
- A general contractor license is required when the cost of the undertaking is $40,000 or more (G.S. 87-1(a)).
- License limits per single project: limited up to $750,000, intermediate up to $1,500,000, unlimited with no cap, excluding land costs (G.S. 87-10(a1)).
Flashcards
Exam tip: Lien deadlines both run from the last furnishing of labor or materials, not from the contract date or the date of the invoice.
How to pass
- North Carolina's stair rules differ from the national IRC. Expect a question on them.
- Tab the Residential Code chapters for foundations (R4), floors (R5), walls (R6) and roofs (R8, R9).
- You need 63 correct out of 90 on the trade section.
Frequently asked questions
How long should I study for the NC Residential exam?
Most working candidates need 4 to 8 weeks at 45 to 60 minutes a day. Book your exam once your Readiness Score has stayed at 80 or higher for about a week.
Is the NC Residential exam open book?
Open book (approved references, including the NC Residential Code). Check the current candidate information bulletin from NC Licensing Board for General Contractors (NCLBGC) for the approved reference list and tabbing rules.
What score do I need to pass the NC Residential exam?
70% on each part (63 of 90 on the trade exam). The exam has 90 trade questions + 40-question business & law section and a time limit of 210 minutes (trade) + 90 minutes (business & law).
What are the most tested topics?
The outline covers foundations and slabs, floor and wall framing, stairs, guards and egress, roofing and attic ventilation, crawl spaces and moisture, fire separation and alarms, residential construction practices, estimating and plan reading, nc business and law. Use the free practice test to see which ones you need most.
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Summarized from official candidate information and the statutes, codes and regulations cited, checked October 2026. Confirm current requirements with NC Licensing Board for General Contractors (NCLBGC).