SGM Southcrete™ CSWK Gray/White 1100 Crack Suppression & Waterproofing Membrane. SGM Southcrete™ 1100 Crack Suppression and Waterproofing is a two part, trowelable, thin, load bearing membrane system for use under thin set and thick bed mortar installations. Southcrete™ 1100 Crack Suppression and Waterproofing Membrane is a two-part, trowelable, thin, load-bearing membrane system for use under thin-set and thick bed mortar installations. Southcrete™ 1100 Crack Suppression and Waterproofing Membrane may be used to reduce transmissions of existing cracks through ceramic tile, marble, and terrazzo floors. It can also be used for residential and commercial applications where complete waterproofing is required. Applications include vertical or horizontal, both interior or exterior (over properly prepared concrete), mortar beds, cementitious backer units, APA exterior grade plywood (interior use only), existing ceramic tile, and drywall.