Building Inspector Practice Questions (ICC B1 and B2)

1. It passes; every riser is under 7¾ inches
2. It passes; up to ½ inch of variation is allowed
3. It fails; risers in a flight may vary only ⅜ inch
4. It fails; no riser may exceed 7 inches in a dwelling

Answer: C. IRC R311.7.5.1 limits riser height to 7¾ inches and limits the difference between the largest and smallest riser in a flight to ⅜ inch; this flight varies by ½ inch, so it fails even though no riser is too tall. The 7-inch maximum riser is the IBC rule for commercial stairs, not the IRC rule.

Topic: Stairs and guards

1. 9 inches
2. 10 inches
3. 11 inches
4. 12 inches

Answer: B. IRC R311.7.5.2 requires a tread depth of at least 10 inches, and where the tread is less than 11 inches a nosing of ¾ to 1¼ inches is required on stairs with solid risers. The 11-inch figure is the IBC minimum for commercial stairs.

Topic: Stairs and guards

1. 28 to 32 inches
2. 30 to 34 inches
3. 32 to 36 inches
4. 34 to 38 inches

Answer: D. Both IRC R311.7.8.1 and IBC 1014.2 require handrail height of 34 to 38 inches measured vertically from the sloped line connecting the tread nosings. The IRC requires a handrail on at least one side of any flight with four or more risers; guard height (36 inches in the IRC) is a separate measurement.

Topic: Stairs and guards

1. 30 inches
2. 34 inches
3. 36 inches
4. 42 inches

Answer: C. IRC R312 requires a guard wherever a walking surface is more than 30 inches above the floor or grade within 36 inches horizontally, and the guard must be at least 36 inches high with openings that reject a 4-inch sphere. The 42-inch height is the IBC requirement for most commercial guards.

Topic: Stairs and guards

1. Yes; it meets the 20-inch width and 24-inch height minimums
2. No; its net clear area is 5.0 square feet, under 5.7
3. No; the clear width must be at least 24 inches
4. Yes; 5 square feet is enough for any bedroom window

Answer: B. IRC Section R310 requires a net clear opening of at least 5.7 square feet, plus a clear height of at least 24 inches and a clear width of at least 20 inches; 20 × 36 inches is 720 square inches, only 5.0 square feet. The 5-square-foot allowance applies only to grade-floor or below-grade openings, and meeting the two minimum dimensions alone gives just 3.3 square feet.

Topic: Means of egress

1. 36 inches
2. 40 inches
3. 44 inches
4. 48 inches

Answer: C. IRC Section R310 limits the sill, the bottom of the clear opening, to 44 inches above the floor so an occupant can climb out and a firefighter can climb in. A window well serving an opening below grade must provide at least 9 square feet with a 36-inch minimum dimension, and a ladder or steps where the well is deeper than 44 inches.

Topic: Means of egress

1. Basements, habitable attics and every sleeping room
2. Every habitable room in the dwelling
3. Only sleeping rooms above the first story
4. Only rooms without a door to the exterior

Answer: A. IRC R310.1 requires at least one operable emergency escape and rescue opening in basements, habitable attics and every sleeping room, opening directly to a public way, yard or court. Living rooms and kitchens have no such requirement, and a basement of 200 square feet or less used only for mechanical equipment is exempt.

Topic: Means of egress

1. About 1½ inches
2. About 2 inches
3. About 2½ inches
4. About 3 inches

Answer: D. IRC R502.8.1 limits a bored hole to one-third of the joist depth (9¼ ÷ 3 is about 3 1/16 inches) and keeps it at least 2 inches from the top and bottom edges and from any other hole. The 1½-inch figure is roughly the one-sixth limit for top or bottom notches, which also may not fall in the middle third of the span.

Topic: Foundations and framing

1. 4 feet
2. 6 feet
3. 8 feet
4. 12 feet

Answer: B. IRC R403.1.6 requires anchor bolts at least ½ inch in diameter, embedded at least 7 inches, spaced no more than 6 feet on center, with at least two bolts per plate section and one bolt within 12 inches (but not less than seven bolt diameters) of each end of the section.

Topic: Foundations and framing

1. To prevent frost heave from lifting and cracking the footing
2. To reach undisturbed soil or bedrock
3. To keep the concrete from freezing while it cures
4. To increase the bearing area of the footing

Answer: A. Water in soil expands when it freezes, and a footing above the frost line can be lifted and dropped each season, cracking the foundation and the structure above. IRC R403.1.4 sets the minimum footing depth at 12 inches below undisturbed ground and R403.1.4.1 requires footings to extend below the frost depth adopted by the jurisdiction, with exceptions such as frost-protected shallow foundations.

Topic: Foundations and framing

1. A 20-minute fire-rated door
2. A hollow-core wood door
3. A 1⅛-inch solid wood door
4. Any insulated exterior door

Answer: A. IRC R302.5.1 requires a solid wood door at least 1⅜ inches thick, a solid or honeycomb-core steel door at least 1⅜ inches thick, or a 20-minute fire-rated door, and it may not open directly into a sleeping room. The separation itself needs ½-inch gypsum board on the garage side of walls and ⅝-inch Type X on a garage ceiling below habitable rooms (R302.6).

Topic: Fire and life safety

1. Nothing; those are the only required locations
2. A basement smoke alarm plus a CO alarm near the bedrooms
3. A smoke alarm in the kitchen
4. A heat detector in the furnace room

Answer: B. IRC R314 requires smoke alarms in each sleeping room, outside each separate sleeping area and on every additional story including basements, interconnected and hardwired with battery backup in new construction. IRC R315 requires carbon monoxide alarms outside each separate sleeping area when the dwelling has fuel-fired appliances or an attached garage. Kitchens are not a required location, and alarms near cooking appliances cause nuisance alarms.

Topic: Fire and life safety

1. Group F
2. Group M
3. Group S
4. Group U

Answer: C. IBC Chapter 3 places storage in Group S (S-1 for moderate-hazard goods such as paper, S-2 for low-hazard noncombustible goods). Group F covers manufacturing, Group M covers the display and sale of merchandise, and Group U covers accessory buildings such as private garages and sheds.

Topic: Inspections and occupancy

1. The building official found the work compliant; occupancy is permitted
2. The contractor has finished all work in the contract
3. The fire department has approved the sprinkler system
4. The final inspection has been scheduled

Answer: A. Under IRC R110 and IBC Section 111, the building official issues the certificate of occupancy after the final inspection finds no violations, and a building or changed occupancy may not be occupied until it is issued. A temporary certificate may be issued for a portion that can be occupied safely before all work is complete.

Topic: Inspections and occupancy

1. Before the roof sheathing is installed
2. Right after the footing inspection is approved
3. After drywall is hung but before taping
4. After rough plumbing, mechanical and electrical approvals, before insulation

Answer: D. IRC R109.1.4 calls for the frame inspection after the roof, masonry, framing, fireblocking, draftstopping and bracing are in place and after the plumbing, mechanical and electrical rough-in inspections are approved, so everything that will be concealed can be seen at once. IBC Section 110 follows the same sequence for commercial work.

Topic: Inspections and occupancy