Louver perimeter caulk cracks because there is no backer rod
Exterior louver joints need the right sealant joint shape. Remove failed caulk, add backer rod where required, and tool an approved exterior sealant system.
Do not fill a deep exterior louver joint with cheap interior caulk and call it weatherproof.
Check
Look for cracked, pulled, or sunken perimeter sealant.
Check whether backer rod or joint backing is missing.
Confirm sealant type is exterior-rated for the wall/louver materials.
Make sure weep paths are not sealed shut.
Tool the joint so it can move without tearing.
Steps
Look for cracked, pulled, or sunken perimeter sealant.
Check whether backer rod or joint backing is missing.
Confirm sealant type is exterior-rated for the wall/louver materials.
Make sure weep paths are not sealed shut.
Tool the joint so it can move without tearing.
Say this to your foreman
The louver perimeter seal at [location] split open and there is no backer rod. Do you want the joint cleaned out and rebuilt with approved backing and exterior sealant?