Window/door flashing: install per manufacturer; where instructions absent, sill PAN FLASHING is required

Description

Flashing at exterior windows and doors must extend to the exterior finish OR a WRB-compliant surface for drainage. Mechanically-attached flexible flashings must comply with AAMA 712. Install per: (1) manufacturer's instructions; (2) a registered design professional's design; OR (3) other approved methods. Where manufacturer instructions don't address it, a SILL PAN FLASHING is required, sloped or sealed to direct water to the exterior wall finish / WRB.

Why this exists

Sill pan flashing is the detail that catches the inevitable small water intrusion at a window sill and drains it out before it rots the framing. Skipping it is a leading cause of sill rot in homes < 10 years old. Architects should call out the sill pan in the window detail — many manufacturers now sell pre-formed pan flashings designed for their products.

Categories

Applies to

• Jurisdiction: New York State

Source

Solver enforcement

Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.

Related directives

• Habitable space minimum ceiling height · IRC R305.1
• Wind design · IRC R301.2.1
• Seismic provisions · IRC R301.2.2
• Snow loads · IRC R301.2.3
• Floodplain construction · IRC R301.2.4