Framing & StructuralQuestion 328 of 700
When a bird's-mouth seat cut is made where a rafter bears on the top plate, what limits how deep that notch may be cut?
a.It may be cut to any depth to fit the plate
b.It must remove exactly half the rafter
c.The remaining rafter depth above the notch must stay adequate; the seat cut should not over-notch the rafter
d.The notch must equal the plate width plus 2 inches
Explanation
A bird's-mouth seat cut removes material where the rafter sits on the plate, but enough rafter depth must remain above the notch to carry the load, so the cut is limited (commonly the notch does not exceed one-quarter to one-third of the rafter depth per design). Cutting to any depth, exactly half, or plate-width-plus-2 are not the governing limits.
Law Reference: 2025 CA Residential Code §R802.7Practice all 700 questions free — no signup required.
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