A multi-section louver leaks at the vertical mullion joint
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.
Do not smear silicone over the exterior face and ignore the internal water management path.
Check
Water-test or trace the leak path at the vertical joint.
Check manufacturer splice/mullion detail and weep path.
Inspect missing internal gutter/splice channel, failed sealant, or blocked weeps.
Coordinate with façade/waterproofing trade before exterior face caulking.
Retest after repair.
Steps
Water-test or trace the leak path at the vertical joint.
Check manufacturer splice/mullion detail and weep path.
Inspect missing internal gutter/splice channel, failed sealant, or blocked weeps.
Coordinate with façade/waterproofing trade before exterior face caulking.
Retest after repair.
Say this to your 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?