Framing & StructuralQuestion 297 of 700
When wood structural panel subfloor or sheathing is installed, what approximate gap is customarily left at panel edges and ends for expansion?
a.No gap; panels must be tightly butted
b.3/4 inch
c.1/8 inch
d.1/2 inch
Explanation
Manufacturers and code commentary call for roughly a 1/8-inch gap at panel edges and ends so moisture swelling does not cause buckling. Butting tight invites buckling; 1/2 and 3/4 inch are far larger than needed and would leave unsupported spans and telegraph through finishes.
Law Reference: 2025 CA Residential Code §R503.2.1Practice all 700 questions free — no signup required.
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