TinnerFlow logoTinnerFlow™
Apprentice answer

Why would rain leak through the center joint of a multi-section louver

3rd YearRoof Curbs, Louvers & Exterior AirCheck first

Multi-section louvers need the approved splice, gutter, sealant, and weep path. Do not rely on face caulk only when water is entering through the mullion joint.

Ask a jobsite questionBack to Roof Curbs, Louvers & Exterior Air

Plain-English answer

Wide louvers often come in sections. The joint between sections needs a proper internal splice/gutter/seal path, not just a bead of caulk smeared on the front.

Find where the water enters and where it should drain. Check the manufacturer louver detail for mullion splice, back pan, sealant, weeps, and flashing. Repair from the internal water path when possible so the joint drains instead of trapping water.

Ask Foreman

The multi-section louver at [location] is leaking down the vertical joint. I checked the mullion/splice and weep path. Do you want the internal splice/gutter detail corrected before more face sealant?

Verify before acting

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

Related questions in this category

Why does an uninsulated louver blank-off panel sweat in cold weather?3rd YearWhat happens if an outside-air intake louver is covered from behind?2nd YearHow should inactive sections of a louver be blanked off?2nd YearHow can you tell if an exterior intake louver is installed the wrong way?2nd YearWhy is water getting under a rooftop curb counter-flashing?3rd YearWhy is an upside-down exterior louver such a big problem?2nd Year