Opening flashing

What opening flashing does

Openings interrupt the building envelope. Flashing, sill pans, drip edges, sealant joints, and compatible membranes must work together so water that reaches the opening is guided back out, not into the wall.

Why it matters for cost

Opening leaks usually appear after interior finishes are complete. That means a small missed detail can become paint repair, plaster removal, joinery damage, facade rework, and warranty conflict.

Common mistakes

• Sill details look neat but have no real drainage path.
• Sealant is used as the only defence instead of a layered flashing strategy.
• Flashing is interrupted by frame fixings, facade returns, or late field changes.

What to verify

• The sill and head details shed water outward.
• Ends, corners, and frame penetrations are treated as part of the system.
• Water cannot track behind cladding or into interior reveals.