Expansion Joint Filling: Sealing the Gaps Buildings Are Meant to Have
Buildings expand and contract with temperature, which is exactly why they have expansion joints. The problem: those same gaps are an open path for water unless they’re sealed with a material that can flex.
Why ordinary filling fails
A rigid filler in a moving joint cracks within a season. Expansion joint filling uses a flexible polyurethane sealant over a backer rod, so the seal stretches and compresses with the building instead of tearing.
How it’s done
- Clean out the joint and remove any old, failed filler.
- Insert a backer rod to set the correct sealant depth and support.
- Apply flexible sealant evenly along the full length of the joint.
- Tool the sealant smooth so it bonds well and flexes with movement.
Where it matters
- Roof and podium expansion joints
- Joints in large concrete slabs
- Junctions between building blocks
- Parking decks and terraces
Because joints often coincide with cracks, this pairs naturally with crack repair & PU filling and full terrace waterproofing.
FAQ
Why does my expansion joint keep leaking? It’s likely sealed with a rigid material that cracked. A flexible sealant over a backer rod solves it.
J.K. Enterprise seals expansion joints on roofs and podiums across Gujarat. Get a free assessment.
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