Floor Slab Isolation Joint

A concrete expansion joint is also used to separate a concrete driveway or patio from a garage slab sidewalk stairway light pole or any other point or restraint.

Floor slab isolation joint.

Joint spacing that is greater than 15 feet require the use of load transfer devices dowels or diamond plates. Isolation joint material should go all the way through the slab starting at the subbase but should not extend above the top. Isolation joints are generally formed by casting against a compressible preformed filler material eg self expanding cork over the full depth of the joint to provide a complete separation. Joint spacing in meters.

What is the difference between a contraction joint isolation joint expansion joint construction joint and a cold joint. Joints should be spaced about 10 feet and a maximum of 15 feet. Isolation joint material should go all the way through the slab starting at the subbase but should not extend above the top. Saw cut joints should be done within 4 to 12 hours after the concrete has been finished.

The joint free slab. Also the floor and the wall usually shrink at different rates and the difference in amount of shrinkage is likely to cause the floor or wall to crack if they interlock. Expansion joints are used in pavements to provide for thermal and moisture induced movement of the slab. And rectangular dowels and for diamond shaped load plates are provided in aci 302 1r 04 guide for concrete floor and slab construction or aci 360r 06 design of slabs on ground.

The perimeter joint prevents this problem. Isolation joints also sometimes functioning as expansion joints. Concrete isolation joints or expansion joints separate or isolate the concrete from other parts of the building structure like walls footings columns and piers. For a cleaner looking isolation joint the top part of the preformed filler can be cut off and the space filled with elastomeric sealant.

Some proprietary joints come with removable caps to form this sealant reservoir. Most details we ve seen recommend not placing the slab directly on the footing but if you ve got enough vertical clearance we think a inch layer of sand would work better than isolation joint material. Maximum joint spacing should be 24 to 36 times the thickness of the slab. Expansion joints which are really isolation joints permit differential settlement of the wall and the floor.

Some proprietary joints come with removable caps to form this sealant reservoir. When using joint groove for contraction joints the joint should be a minimum depth of thickness of the slab. If you don t have the clearance a layer of 30 pound roofing felt should work. A contraction joint is formed sawed or tooled groove in a concrete structure to create a weakened plane to regulate the location of cracking resulting from the dimensional change of different parts of the structure.

For a cleaner looking isolation joint the top part of the preformed filler can be cut off and the space filled with elastomeric sealant.