R507.1
Exterior Deck Requirements
DECK CONSTRUCTION: Live load 40 psf, dead load 10 psf minimum. LEDGER: Use Table R507.9.1.3(1) for bolt sizing/spacing - typically 1/2" lag screws at 12-16" o.c. staggered. GUARDS: Required when deck >30" above grade - minimum 36" height (42" for commercial). PROPER FLASHING: Z-flashing or self-adhering membrane behind ledger, with drip edge.