Setting blocks, usually EPDM, neoprene or silicone of a set hardness, sit under the glass at quarter points or eighth points of its width and are sized by the glass weight. They center the glass, keep it from contacting metal and leave room for drainage. The block material must be compatible with the sealants, especially in structural silicone glazing.
Setting blocks walked to the middle and the lite is sitting on the frame, that's why it cracked.
Also heard as
- setting blocks
- glazing block
Related terms
Lite
A single pane or unit of glass in a window, door or curtain wall opening.
Compatibility test
A lab check that a sealant and the materials it touches do not react, discolor or lose adhesion together.
Heel bead
A sealant bead at the inside edge of the glass where it meets the frame, forming a continuous air and water seal.
SSG
Structural silicone glazing, where glass is held to its frame by silicone instead of exterior caps or stops.