TinnerFlow™2nd YearYELLOW · Check FirstFailed Perimeter Sealant
Exterior louver joints need the right sealant joint shape. Remove failed caulk, add backer rod where required, and tool an approved exterior sealant system.
A perimeter seal is not just a smear of caulk. If the joint is too deep or bonded on three sides, movement and heat can split it open quickly.
Clean out failed sealant, install the right backing material where the joint calls for it, then apply the approved exterior-grade sealant with the proper profile. Coordinate with the waterproofing/envelope detail so the sealant works with the flashing, not instead of it.
Do not fill a deep exterior louver joint with cheap interior caulk and call it weatherproof.
A failed perimeter joint lets rain bypass the louver frame and enter the wall.
Final direction belongs to the foreman, approved drawings/specs, manufacturer instructions, pressure/material schedule, employer policy, and AHJ/code requirements.