Floor Slab Isolation Joint

What is the difference between a contraction joint isolation joint expansion joint construction joint and a cold joint.

Floor slab isolation joint.

Expansion joints which are really isolation joints permit differential settlement of the wall and the floor. For a cleaner looking isolation joint the top part of the preformed filler can be cut off and the space filled with elastomeric sealant. Maximum joint spacing should be 24 to 36 times the thickness of the slab. For a cleaner looking isolation joint the top part of the preformed filler can be cut off and the space filled with elastomeric sealant.

Concrete isolation joints or expansion joints separate or isolate the concrete from other parts of the building structure like walls footings columns and piers. When using joint groove for contraction joints the joint should be a minimum depth of thickness of the slab. 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. 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.

Isolation joint material should go all the way through the slab starting at the subbase but should not extend above the top. Some proprietary joints come with removable caps to form this sealant reservoir. The perimeter joint prevents this problem. The joint free slab.

Isolation joint material should go all the way through the slab starting at the subbase but should not extend above the top. Joint spacing that is greater than 15 feet require the use of load transfer devices dowels or diamond plates. 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. Isolation joints also sometimes functioning as expansion joints.

Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness. Joint spacing in meters. Expansion joints are used in pavements to provide for thermal and moisture induced movement of the slab. The idea is to reduce restraint so your slab doesn t crack.

Some proprietary joints come with removable caps to form this sealant reservoir. 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. Joints should be spaced about 10 feet and a maximum of 15 feet. Joint spacing in feet contraction joints may be tooled into the concrete surface at the time of placement.

Saw cut joints should be done within 4 to 12 hours after the concrete has been finished.