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Residential Building Inspector B1 practice questions

229 free questions with answers and explanations.

Practice test
  1. 101.A building inspector is reviewing plans for a new residential structure. The plans indicate that the soil under the footings has a presumptive load-bearing value of 1,500 psf. The proposed continuous footing is 16 inches wide and supports a wall with a design load of 1,200 pounds per linear foot (plf). Based on the 2021 IRC, what is the minimum required width for this footing?Footings and Foundations
  2. 102.A residential building is being constructed on a site where the soil is classified as 'clayey sand' (SC) according to the Unified Soil Classification System (USCS). What is the presumptive load-bearing value for this soil type as per the 2021 IRC?Footings and Foundations
  3. 103.A residential building inspector is reviewing plans for a new single-family dwelling. The plans indicate that the dwelling will have a common laundry area. What is the minimum required diameter for the standpipe receptor into which the clothes washer discharge hose will empty?Building Planning and Life Safety
  4. 104.A residential building inspector is reviewing the installation of roof sheathing on a new construction project. The roof has a rafter spacing of 24 inches on center. What is the minimum nominal thickness required for plywood roof sheathing with a span rating of 24/16?Roof-Ceiling Construction
  5. 105.A residential building inspector is reviewing plans for a new single-family dwelling. The plans include a stairway with a closed riser design. What is the maximum riser height permitted for this stairway?Building Planning and Life Safety
  6. 106.A builder is constructing a roof in a region where the average January temperature is 25°F (-4°C). The roof has an eave overhang of 18 inches. According to the IRC, what is the minimum required dimension for the ice barrier membrane measured from the lowest edges of the roof surface?Roof-Ceiling Construction
  7. 107.A residential building inspector is reviewing plans for a new single-family dwelling. The plans indicate the installation of a permanently installed generator. What is the minimum required distance the generator must be located from any opening in the dwelling?Building Planning and Life Safety
  8. 108.A residential building inspector is reviewing plans for a new single-family dwelling that includes a window in a bathroom. What is the minimum required amount of glazing area, as a percentage of the floor area, for natural light in this bathroom?Building Planning and Life Safety
  9. 109.A residential building inspector is reviewing plans for a new single-family dwelling that includes a concrete foundation wall. If the concrete is specified to have a minimum compressive strength of 2,500 psi at 28 days, what is the maximum water-cementitious materials ratio (w/cm) allowed for this concrete when exposed to severe weathering?Building Planning and Life Safety
  10. 110.A residential building inspector is reviewing plans for a new single-family dwelling that includes a guardrail along an open-sided floor area. What is the minimum required height for this guardrail, measured vertically from the leading edge of the walking surface?Building Planning and Life Safety
  11. 111.A residential building inspector is evaluating the roof framing of a new home. The rafters are spaced 24 inches on center and span 12 feet. The ceiling joists are also spaced 24 inches on center and are nailed to the sides of the rafters. What is the minimum number of 10d common nails required for each rafter-to-ceiling joist connection to act as a rafter tie?Roof-Ceiling Construction
  12. 112.An inspector is reviewing plans for a new single-family dwelling. The plans indicate the installation of a permanently installed outdoor barbecue grill. What is the minimum required distance from the sides and rear of the grill to combustible construction?Building Planning and Life Safety
  13. 113.A residential building inspector is performing a rough-in inspection for a new dwelling. The plans indicate that the wall sheathing will be installed directly over the studs. What is the minimum nominal thickness of wood structural panel wall sheathing required to be fastened to studs spaced 24 inches on center?Building Planning and Life Safety
  14. 114.An inspector is reviewing the design for a residential roof system that includes a valley. The plans specify the use of an open valley method for asphalt shingles. What is the minimum width required for the metal valley flashing at the top of the valley?Roof-Ceiling Construction
  15. 115.An inspector is evaluating the attic ventilation system for a single-family dwelling. The attic has a total area of 1,500 square feet and is provided with both soffit and ridge vents. What is the minimum net free ventilating area required for this attic?Roof-Ceiling Construction
  16. 116.An inspector is performing a final inspection of a newly constructed single-family dwelling. The dwelling includes a clothes dryer that exhausts through a flexible transition duct to the main exhaust duct. What is the maximum length permitted for this flexible transition duct?Building Planning and Life Safety
  17. 117.An inspector is checking the installation of a standing seam metal roof. The roof has a pitch of 3:12. What is the minimum required overlap for the side laps of the metal roof panels?Roof-Ceiling Construction
  18. 118.A residential building inspector is reviewing plans for a new single-family dwelling. The plans include a stairway with a total rise of 100 inches. What is the minimum required headroom for this stairway?Building Planning and Life Safety
  19. 119.A residential building inspector is performing a framing inspection for a new dwelling. The plans indicate a wood structural panel subfloor. What is the minimum required nominal thickness for a wood structural panel subfloor where the floor joist spacing is 16 inches on center and the panel is not tongue and groove?Building Planning and Life Safety
  20. 120.An inspector is reviewing a proposed residential deck that will be attached to a dwelling. The deck ledger board is to be attached to the band joist of the existing dwelling. What is the minimum diameter of lag screws required for attaching the ledger board to the dwelling's band joist?Building Planning and Life Safety
  21. 121.A residential building inspector is examining the attic ventilation system. The attic has a total net free ventilating area of 144 square inches (929 cm²). The attic floor area is 1,200 square feet (111.5 m²). Is this attic adequately ventilated according to the minimum IRC requirements when no special exceptions apply?Roof-Ceiling Construction
  22. 122.A builder is constructing a new detached garage on a property. The garage will be located 3 feet from the residential dwelling on the same lot. What is the minimum fire-resistance rating required for the exterior wall of the garage that faces the dwelling?Building Planning and Life Safety
  23. 123.A residential building inspector is reviewing plans for a new single-family dwelling. The plans indicate that the dwelling will have a conditioned floor area of 2,500 square feet and will be constructed with wood framing. What is the minimum required R-value for the ceiling insulation in Climate Zone 5?Building Planning and Life Safety
  24. 124.A residential building inspector is reviewing plans for a new dwelling with an attached garage. The wall separating the garage from the dwelling is specified as a 1/2-inch gypsum board on the garage side. What is the minimum fire-resistance rating required for this wall?Building Planning and Life Safety
  25. 125.A residential building inspector is reviewing plans for a new single-family dwelling that includes an under-stair storage area. This area is enclosed and located beneath a required exit stairway. What is the minimum fire-resistance rating required for the enclosure walls and ceiling of this storage area?Building Planning and Life Safety
  26. 126.A residential building inspector is reviewing plans for a new single-family dwelling that includes an attic space. The plans indicate that the attic will contain mechanical equipment requiring periodic access. What is the minimum clear height required for the access opening into this attic space?Building Planning and Life Safety
  27. 127.An inspector is reviewing the installation of a new roof covering on a residential structure. The roof has a pitch of 1:12. Which of the following roof coverings is permitted for this pitch according to the IRC?Roof-Ceiling Construction
  28. 128.A homeowner is installing new gutters on a residence. The roof area draining into a single downspout is 1,200 square feet (111.5 m²). The local design rainfall rate is 6 inches (152 mm) per hour. What is the minimum required cross-sectional area for the downspout, assuming a standard rectangular downspout?Roof-Ceiling Construction
  29. 129.An inspector is reviewing plans for a residential roof. The plans indicate the use of asphalt shingles on a roof with a pitch of 2:12. What is the minimum required underlayment for this roof pitch according to the IRC?Roof-Ceiling Construction
  30. 130.A residential building inspector is performing a final inspection of a newly constructed single-family dwelling. The dwelling includes a permanently installed clothes dryer. What is the maximum length permitted for a 4-inch (102 mm) diameter smooth-wall flexible metal duct for a clothes dryer exhaust?Building Planning and Life Safety
  31. 131.A residential building inspector is conducting a framing inspection for a new single-family dwelling. The plans indicate the use of continuous concrete foundations. What is the minimum required thickness for a concrete foundation wall that supports a wood-frame wall?Building Planning and Life Safety
  32. 132.A residential building inspector is reviewing the plans for a new dwelling. The plans indicate that the dwelling will be constructed in a seismic design category D2. What is the minimum required strength of concrete for the foundation walls in this category, assuming standard residential construction?Building Planning and Life Safety
  33. 133.A homeowner is installing new interior gypsum board on walls and ceilings in a new addition. The wall studs are spaced 16 inches on center. What is the minimum nominal thickness of gypsum board required for these wall applications?Building Planning and Life Safety
  34. 134.A residential building inspector is performing a final inspection of a roof covering. The roof has a pitch of 6:12 and is covered with concrete tiles. What is the minimum required overlap for the concrete tiles?Roof-Ceiling Construction
  35. 135.An inspector is reviewing a proposed new single-family dwelling. The plans include a habitable attic space. What is the minimum required aggregate area of operable skylights or windows for natural ventilation in this habitable attic, assuming the floor area is 400 square feet?Building Planning and Life Safety
  36. 136.A residential building inspector is performing a framing inspection for a new dwelling. The plans specify a 2x6 wood stud wall. What is the maximum height permitted for a load-bearing exterior wall constructed with 2x6 studs, spaced 16 inches (406 mm) on center, with a single top plate, supporting a roof and ceiling only, with a maximum wind design speed of 100 mph (161 km/h)?Building Planning and Life Safety
  37. 137.During a roof inspection, an inspector notes that the roof framing consists of trusses with a bottom chord used as the ceiling joist. The trusses are spaced 24 inches on center. What is the minimum required size for collar ties or rafter ties in this type of roof construction to resist rafter spread, assuming a typical roof pitch and span?Roof-Ceiling Construction
  38. 138.A residential building inspector is reviewing plans for a new dwelling located in a wildland-urban interface (WUI) area. The plans specify the use of exterior wall coverings. What is the minimum fire-resistance requirement for the exterior wall covering in this WUI area?Building Planning and Life Safety
  39. 139.An inspector is reviewing the plans for a new single-family dwelling that includes a bathroom with a shower. The shower stall will have a finished dimension of 30 inches by 30 inches. What is the minimum interior dimension allowed for a shower compartment?Building Planning and Life Safety
  40. 140.A residential building inspector is performing a rough-in inspection for a new dwelling. The plans show a shower compartment. What is the minimum required finished interior dimension from the shower control wall to the opposing wall?Building Planning and Life Safety
  41. 141.A residential building inspector is reviewing plans for a new single-family dwelling. The plans indicate the installation of a permanently installed outdoor barbecue grill on a combustible deck. What is the minimum clearance required from the sides and rear of the grill to combustible materials?Building Planning and Life Safety
  42. 142.A residential building inspector is performing a rough-in inspection for a new dwelling. The plans indicate the installation of 1/2-inch gypsum board on interior walls. What is the maximum stud spacing permitted for 1/2-inch gypsum board installed parallel to the framing members?Building Planning and Life Safety
  43. 143.An inspector is examining the roof framing of a new single-family residence. The rafters are 2x8s spaced at 24 inches on center. The attic space is unvented and insulation is installed directly against the underside of the roof sheathing. What is the minimum required clear airspace between the insulation and the roof sheathing for this assembly?Roof-Ceiling Construction
  44. 144.A residential building inspector is reviewing plans for a new single-family dwelling. The plans include a habitable attic space. What is the minimum clear headroom required in the habitable attic space over at least 50 percent of its area?Building Planning and Life Safety
  45. 145.A residential building inspector is reviewing plans for a new single-family dwelling that includes an attached garage. What is the minimum fire-resistance rating required for the wall separating the garage from the dwelling unit?Building Planning and Life Safety
  46. 146.A residential building inspector is reviewing plans for a new single-family dwelling that includes an outdoor air conditioning condenser unit. The plans show the unit placed near an exterior wall. What is the minimum required clearance between the air conditioning condenser unit and the exterior wall to ensure proper airflow and maintenance?Building Planning and Life Safety
  47. 147.A residential building inspector is reviewing plans for a new single-family dwelling. The plans indicate the installation of a new gas-fired water heater in the garage. What is the minimum height above the garage floor that the ignition source of this water heater must be located?Building Planning and Life Safety
  48. 148.A residential building inspector is reviewing the installation of roof sheathing. The roof rafters are spaced 24 inches on center. What is the minimum nominal thickness of plywood sheathing required for a roof with this rafter spacing, assuming the sheathing is applied with the long dimension perpendicular to the rafters?Roof-Ceiling Construction
  49. 149.A residential building inspector is reviewing plans for a new single-family dwelling that includes a fireplace. The plans indicate the fireplace will have a masonry hearth. What is the minimum required thickness for this masonry hearth?Building Planning and Life Safety
  50. 150.A residential building inspector is performing a final inspection of a roof covering. The contractor has installed asphalt shingles on a roof with a pitch of 5:12. What is the minimum number of fasteners required per shingle for standard asphalt shingle application, excluding special high-wind areas?Roof-Ceiling Construction