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Apprentice Q&A · #254

How can you tell if an exterior intake louver is installed the wrong way?

2nd YearLouvers / Exterior IntakeRED · Stop / Verify

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.

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Plain-English answer

An exterior louver is not just a grille. It sheds rain, blocks debris, and directs air. If the blades pitch the wrong way, the louver can collect water and dump it into the wall, plenum, or mechanical room.

Verify the manufacturer orientation, drain sill, bird screen side, airflow direction, and wall flashing before cover. The likely fix is to pull and reinstall the louver correctly, then reseal/flashing per the approved exterior wall detail.

Field checklist

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?

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Verify before acting

Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.

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