Bridge joints span over a gap with a flat band of sealant or a preformed silicone extrusion bonded on both sides, with bond breaker tape in the middle so the band can flex. They are used when the original joint cannot be cut out, when it is too narrow, or over failed joints during repairs. The band bonds to weathered faces, so adhesion there decides how long the repair lasts.
Joint's too tight to cut out, so we'll do a bridge joint with the silicone extrusion over bond breaker tape.
Run pull tests on the faces where a bridge joint will bond, because weathered paint or coating often fails under it before the sealant does.
Also heard as
- bridge seal
- overband
Related terms
Band-aid
A bridge joint applied over an existing sealant joint as a repair, without removing the old material.
Bond breaker
A tape or material at the back of a joint that sealant will not stick to, preventing three-sided adhesion.
R&R
Remove and replace: cutting out old sealant completely and installing new sealant in the cleaned joint.
Field adhesion test
A test that cuts a tab of cured sealant from an installed joint and pulls it to see whether it lets go of the substrate.