Why does a large exterior louver bank need a sill pan flashing?

Field answer

Big louver banks can take real rain load. The bottom of the opening needs a way to collect and direct water back out. Raw concrete can absorb water and let it migrate into the wall or penthouse.

Before final setting, check the sill pan, end dams, drip edge, bed sealant, and weep path. If the pan is missing, hold the install and coordinate a proper metal sill pan or envelope detail before anchoring the frames permanently.

What to check first

• Look under the louver frame for a continuous sill pan/flashing.
• Check for turned-up end dams and front drip path.
• Verify the pan ties into the wall waterproofing.
• Make sure the pan drains to the exterior, not into the wall.
• Do not final-anchor the bank until base flashing is resolved.

Why it matters

Missing base flashing can create hidden water migration and structural wall damage.

Ask foreman

Text this wording

Related Field Rescue route

Open routeBack to Q&A

Final direction belongs to the foreman, approved drawings/specs, manufacturer instructions, pressure/material schedule, employer policy, and AHJ/code requirements.