ASHI Structural Systems 5 — Questions and Answers
Question 1: What is the purpose of a shear wall in residential construction?
- To distribute vertical gravity loads evenly to the foundation
- To resist lateral forces such as wind and seismic loads in the plane of the wall (Correct answer)
- To provide thermal separation between conditioned and unconditioned spaces
- To carry concentrated point loads from beams to footings
Correct answer: To resist lateral forces such as wind and seismic loads in the plane of the wall
Shear walls are structural panels designed to resist in-plane lateral forces from wind or seismic activity, preventing racking of the building frame.
Question 2: An inspector finds a floor joist that has been notched at the bottom edge near mid-span. Why is this a deficiency?
- Bottom-edge notching near mid-span cuts into the maximum tension zone of the joist (Correct answer)
- The notch weakens the shear zone at the joist bearing
- Notching reduces the fire resistance rating of the floor assembly
- Bottom notches collect moisture and accelerate decay
Correct answer: Bottom-edge notching near mid-span cuts into the maximum tension zone of the joist
The bottom edge of a simply supported joist at mid-span is in maximum tension; notching there removes critical material and can cause catastrophic failure.
Question 3: During a home inspection, a pier-and-beam foundation is found to have several wood piers that are out of plumb. What is the primary concern?
- Out-of-plumb piers create eccentric loading that reduces their load-carrying capacity (Correct answer)
- Leaning piers indicate the soil has too much clay content
- Out-of-plumb piers increase moisture exposure on the wood
- Leaning piers will cause uneven heat distribution in the floor above
Correct answer: Out-of-plumb piers create eccentric loading that reduces their load-carrying capacity
When a pier leans, the load is applied off-center (eccentric), introducing bending into a member designed only for compression, greatly reducing capacity.
Question 4: What is a 'point load' and why is it significant in home inspections?
- A load distributed evenly across an entire floor system
- A concentrated force applied to a small area that can overstress local framing (Correct answer)
- The weight of waterborne moisture absorbed by structural wood
- The pressure exerted by soil on a foundation wall
Correct answer: A concentrated force applied to a small area that can overstress local framing
A point load is a concentrated force at a single location; without proper framing to distribute it, it can overstress beams, joists, or columns beneath it.
Question 5: What does an inspector look for when evaluating the condition of a wood girder in a basement?
- Checking (surface cracks along the grain), end bearing length, and signs of decay or insect damage (Correct answer)
- Paint adhesion, color consistency, and surface smoothness
- Moisture content tags, mill stamps, and grade marks only
- Presence of insulation wrap and vapor barrier on all sides
Correct answer: Checking (surface cracks along the grain), end bearing length, and signs of decay or insect damage
Inspectors evaluate wood girders for surface checking, adequate bearing length at supports, decay, and evidence of wood-destroying insect damage.
Question 6: Which observation would indicate that a roof structure has experienced long-term overloading?
- Sagging or deflection of rafters between supports (Correct answer)
- Slight discoloration of the roof sheathing from age
- Gaps in the ridge cap shingles
- Minor weathering of exposed rafter tails
Correct answer: Sagging or deflection of rafters between supports
Sagging or mid-span deflection in rafters is a visual sign that they have been overstressed over time, potentially from heavy snow loads, added roofing layers, or undersizing.
Question 7: A home inspector observes that a flush beam (dropped beam) supporting floor joists is visibly deflecting. What should be reported?
- The beam is too long and should be replaced with two shorter beams
- Excessive deflection indicates the beam may be undersized, overloaded, or damaged (Correct answer)
- Slight deflection is always acceptable and requires no action
- The deflection is caused by joist hangers pulling the beam down
Correct answer: Excessive deflection indicates the beam may be undersized, overloaded, or damaged
Visible beam deflection exceeding normal limits signals that the beam may be inadequate for the load it carries, potentially requiring engineering evaluation.
ASHI Structural Systems 5
What is the purpose of a shear wall in residential construction?