Structural Systems Flashcards

What is the primary purpose of a let-in brace (diagonal brace) in older wood-frame walls?

Answer: To resist racking forces and provide lateral stability to the wall

Let-in braces are diagonal members notched into studs to resist horizontal (racking) forces from wind or seismic loads, providing lateral stability before plywood sheathing became standard.

A home inspector finds that a crawl space has wood posts sitting on soil without any footings. What is the primary structural concern?

Answer: Inadequate bearing area will cause posts to sink as soil compresses under load

Posts without footings concentrate loads on a small soil area, causing settlement or differential movement as the soil compresses, which can distort the entire floor system.

Which of the following best describes the function of a king stud in door or window framing?

Answer: It is a full-height stud that runs from bottom plate to top plate alongside the trimmer stud

King studs are full-height studs nailed alongside trimmer (jack) studs at each side of an opening; they support the top plate and carry loads around the header.

When a home inspector observes that a masonry chimney has separated from the house framing and is leaning away from the structure, the most likely cause is:

Answer: Differential foundation settlement between the chimney and the house

Chimney lean or separation from the house typically results from differential settlement, where the chimney's independent footing settles at a different rate than the house foundation.

Which of the following roof shapes is inherently the most structurally stable and best at resisting wind uplift?

Answer: Hip roof

Hip roofs slope on all four sides, which distributes wind loads more evenly, eliminates large gable end surfaces prone to uplift, and creates a more aerodynamically stable form.

A home inspector notices that the main carrying beam (girder) in a basement spans between steel columns. One column has a significant lean. This is most significant because:

Answer: A leaning column may have reduced load-bearing capacity and could indicate foundation movement

A leaning steel column has eccentric loading that can buckle the column and may indicate the base plate or footing has shifted, reducing overall structural capacity.

What condition is indicated when a home inspector observes stair-step cracking in the mortar joints of a brick veneer wall?

Answer: Foundation movement causing differential settlement of the veneer

Stair-step cracks follow the mortar joints in a diagonal pattern and are a classic sign that differential foundation settlement is causing the masonry to shift and crack along its weakest path.