When railings are required
Most codes require guardrails on decks 30 inches or more above grade.
- 36–42 inch rail height common
- 4-inch max baluster gap for child safety
- Graspable handrails on stairs
Railing materials
Wood, aluminum, cable, and glass each meet code when installed to spec.
- Cable rails need proper tension
- Glass panels need tempered safety glass
- Post attachment to framing, not decking only
Permits and inspection
Permitted decks protect resale and insurance. Inspectors check footings, ledger attachment, and guards.
- Ledger flashing to the house
- Call 811 before digging footings
- Final inspection before furniture load
Guards versus handrails
A guard keeps people from falling off the edge. A handrail is what you grab on the stair. Cable and glass can meet guard rules and still fail as a stair handrail if there is nothing graspable. Do not assume a pretty top rail is legal on the stairs.
- 4-inch sphere rule for openings is the usual child-safety test
- Stair handrails need a profile you can actually close a hand around
- Measure finished deck height, not the height before the new boards
Where railings fail inspection
Posts lagged only through composite boards, missing ledger flashing, and stairs with uneven risers. Inspectors also catch footings that ignored underground utilities. Call 811 before you dig.
- Attach posts to the joist or blocking per the railing manufacturer
- Tempered glass is not optional on a glass infill
- Final inspection should happen before the furniture and grill go on