Framing & StructuralQuestion 436 of 700
Under conventional framing rules, deep solid-sawn floor joists (such as nominal 2x10 or 2x12) generally require blocking or bridging installed at intervals not exceeding what maximum spacing?
a.4 feet on center along the joist span
b.8 feet on center along the joist span
c.12 feet on center along the joist span
d.No blocking is ever required for solid-sawn joists
Explanation
Deep joists whose depth-to-thickness ratio exceeds about six can twist or buckle, so blocking or cross bridging is required at intervals no greater than 8 feet along the span. 4 feet is stricter than the code minimum; 12 feet exceeds the limit and would leave the joists poorly restrained; claiming blocking is never required ignores lateral-stability rules for tall members.
Law Reference: 2025 CA Residential Code §R502.7Practice all 700 questions free — no signup required.
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