SPONGE RUBBER EXPANSION JOINT is produced to a uniform thickness and density from gray-colored, top-quality, blown sponge rubber. It is easily compressed and has a recovery of 95% or more of the original thickness and a density of not less than 30 pounds per cubic foot (480.56 kg per cubic meter).

The type of control joint and spacing used will vary with each project according to the type of structure, climatic conditions and anticipated stresses in the concrete. Thinner joints of 1/4” (6.35 mm), 3/8” (9.53 mm) or 1/2” (12.7 mm) spaced at frequent intervals offer greater control than thicker joints spaced at greater intervals. The basic objective is to provide ample room for the concrete to expand or contract without creating damaging stresses. Expansion joints should be positioned against forms at interrupting objects or columns and against abutting structures prior to the placement of the concrete. ASPHALT EXPANSION JOINT should be recessed 1/4” (6.35 mm) below the concrete surface. A sealant is not required. FIBRE, CERAMAR, SPONGE RUBBER, CORK and SELF- EXPANDING CORK EXPANSION JOINT should be recessed 1/2” (12.7 mm) below the concrete surface to accept the joint sealant. To isolate filler from sealant, use SNAP-CAP. (Refer to data sheet #324.)

SNAP-CAP should be installed flush with the surface. After removal of the top section of SNAP-CAP, the joint opening is ready for sealing with a suitable sealant from W. R. MEADOWS. NOTE: A joint sealer is not required for ASPHALT EXPANSION JOINT.

Suitable sealants for horizontal applications of CORK and SELF-EXPANDING CORK EXPANSION JOINT are #164, HI-SPEC, SOF-SEAL, GARDOX, DECK-O-SEAL® and SAFE-SEAL® 3405. GARDOX and DECK-O-SEAL are recommended for use with SPONGE RUBBER EXPANSION JOINT. The recommended sealant for vertical applications is DECK-O-SEAL GUN GRADE.