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Finishesaka: joint sealantaka: caulking sealantaka: weatherseal

Sealant

In Plain English

A material applied to joints and gaps to prevent water, air, or fire from passing through.

Definition

A sealant is a flexible or semi-rigid material used to seal joints, gaps, and penetrations in building assemblies against air, water, sound, fire, or thermal transfer. Sealants differ from caulks in that they are engineered for specific movement capability and substrate compatibility. Common types include silicone, polyurethane, polysulfide, and intumescent sealants. Joint design must account for movement range to prevent sealant failure.

Example

The glazing contractor used a two-part polyurethane sealant at all curtain wall joints, rated for 50% movement capability.

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