InterNACHI Structural Systems & Components 2 — Questions and Answers
Question 1: What does a 'cathedral ceiling' configuration typically eliminate that affects roof structural design?
- Collar ties
- Attic space for a horizontal ceiling joist system (Correct answer)
- Ridge board
- Rafter tails
Correct answer: Attic space for a horizontal ceiling joist system
Cathedral ceilings remove the attic space, eliminating the horizontal ceiling joists that normally resist outward thrust from rafters, requiring alternative solutions like ridge beams or structural connectors.
Question 2: Which type of foundation wall crack is most indicative of differential settlement?
- Horizontal crack near mid-height of a block wall
- Diagonal stair-step crack in a masonry block wall (Correct answer)
- Vertical crack at a wall corner
- Uniform hairline cracks throughout the wall
Correct answer: Diagonal stair-step crack in a masonry block wall
Diagonal stair-step cracks in masonry block walls typically indicate differential settlement, where one section of the foundation is moving more than another.
Question 3: What is the primary structural purpose of cross-bridging or blocking between floor joists?
- To support plumbing pipes
- To prevent lateral rotation and distribute loads between joists (Correct answer)
- To act as a fire stop
- To provide nailing surface for subfloor
Correct answer: To prevent lateral rotation and distribute loads between joists
Cross-bridging and blocking prevent lateral rotation (twisting) of floor joists and help distribute concentrated loads to adjacent joists.
Question 4: A home inspector observes that a load-bearing wall has been removed and a header installed. What additional concern should be noted if no posts are visible at the header ends?
- The header may be too wide
- The load may not be transferred properly to the foundation without adequate bearing posts (Correct answer)
- The header finish material may be wrong
- The ceiling height may be non-standard
Correct answer: The load may not be transferred properly to the foundation without adequate bearing posts
Header loads must be transferred down to the foundation through bearing posts or columns; missing posts mean the load path is interrupted and the structure may be compromised.
Question 5: Which condition in a wood-framed wall most significantly reduces its load-bearing capacity?
- Paint on the studs
- Large notches or holes cut in the middle third of studs (Correct answer)
- Double top plate joints that are offset by 24 inches
- Insulation between studs
Correct answer: Large notches or holes cut in the middle third of studs
Large notches or holes cut into studs, especially near mid-height, dramatically reduce the stud's ability to carry vertical loads and resist buckling.
Question 6: What is a 'bearing wall' as defined in residential construction?
- Any wall with drywall on both sides
- A wall that supports the weight of floors, roofs, or other walls above it (Correct answer)
- A wall that runs parallel to floor joists
- A wall located at the exterior perimeter only
Correct answer: A wall that supports the weight of floors, roofs, or other walls above it
A bearing wall supports structural loads from above, including floors, roofs, or other framing, and transfers those loads to the foundation.
Question 7: When inspecting a crawl space, a home inspector notices that several support posts rest directly on the soil without footings. What is the primary concern?
- The posts may rot faster
- Settlement and shifting of posts due to lack of proper load distribution to stable soil (Correct answer)
- The posts may not meet height requirements
- Moisture may enter through the soil
Correct answer: Settlement and shifting of posts due to lack of proper load distribution to stable soil
Without footings, posts can sink unevenly into soil as loads are not distributed over an adequate bearing area, leading to structural settlement and potential failure.
InterNACHI Structural Systems & Components 2
What does a 'cathedral ceiling' configuration typically eliminate that affects roof structural design?