Static field route #19079

What do I do when an exterior louver is installed upside down or backwards?

Equipment Connections: RTU, AHU, VAV, Fans & Louvers🟥 STOP / VERIFYV190 answer-gap expansion

📖 Verified core answer

Stop before siding/sealing finishes. Louvers have drainage/weather orientation; verify label/blade direction and reinstall per manufacturer/detail if water can be driven into the building.

Open in Field Rescue Open category

Field verification checklist

Check blade slope, drain sill, weep path, bird screen side, and orientation labels.
Look from outside to see whether rain would shed out or funnel inward.
Verify exterior wall flashing and sealant sequence.
Stop adjacent finish work if the louver has to be removed.
Photo the condition before correction.

Ask foreman

This exterior louver at [location] appears oriented wrong; the blades/drain path look like they could direct water inward. I checked labels and bird screen side. Do you want it pulled and reinstalled per the manufacturer/wall detail before finish work continues?

Text to foreman

Route options

AMake the field correction only if it is within your assignment and the approved method.

BHold and document the condition if the fix affects airflow, access, life safety, pressure class, rated assemblies, equipment, or another trade.

CBring the foreman/detailer the location, what you checked, and what decision you need before cover, startup, or rework.

Do not do this

Do not seal around an upside-down louver and hope caulk keeps rain out.

Why this matters

A reversed louver can cause serious water intrusion, wall damage, equipment damage, and callbacks after the first storm.

Verification basis

Approved drawings/specs, project coordination drawings, manufacturer instructions/submittals, shop standards, foreman/detailer direction, employer policy, and AHJ/code requirements.