Brick Wall to Frame Wall

to lav and avoids the cracking that might be caused by the shrinkage of the new mortar. ■

Backer rod

Backer rod

Large surfaces of materials that tend to expand after installation should be divided into smaller surfaces by a regular pattern of expansion joints.

1. This expansion joint accessory for plaster allows for the slight expansion in the curing plaster, as well as for subsequent moisture movement and movement in the underlying structure of the wall. The metal lath must be discontinuous along the line of the joint to allow for free movement. The expansion joint accessory is a simple metal or plastic bellows shape. At the time it is installed, it is closed with a plastic tape that prevents it from becoming clogged with plaster, which would be unsightly and would destroy its function. After the plaster has been applied, the tape is stripped away, creating a straight, clean, dark shadow line in the plaster surface. As with any joint, the pattern created by the expansion joints should be worked out and described to the builder in elevation view.

2. Long walls of brick masonry are subject to expansion as the bricks absorb moisture and require periodic expansion joints to relieve the pressure that this otherwise would cause. Any reinforcing in the brickwork should be discontinued across the joint. In masonry expansion joints, it is often important that a spline or tongue-and-£TOOvc feature be provided that will maintain the alignment of the wall while allowing for the necessary in-plane movement.

S. Expansion joints in any material should be located at lines of structural

0 0

Post a comment