Concrete Expansion Joint Installation

Expansion Joints

• Expansion, or isolation, joints separate a slab from footings and walls, or driveways and patios from walkways, retaining walls and steps. The joints permit independent lateral and vertical movement between concrete masses, and reduce cracking.

Depth and Dowels

• Expansion joints are set to the full depth of concrete. Adjacent structures are often dowelled to each other with steel to prevent vertical movement, especially where soils have a high shrink-swell rate, such as clay. All expansion joints should be shown on the construction plans.

Filler and Sealant

• The joints are filled and sealed with special material. Joint filler is soft, made of flexible material such as fiber, cork or foam rubber, and reaches the full length of the joint. Joint sealant keeps the filler material in and water and debris out.