Waterproof protection for joists that prevents rotting of structural timber under exterior floors, such as patios and balconies. The joist guard is a 0.6 mm self-adhesive waterproofing membrane made of elastomeric SBS bitumen and a polyethylene film on the surface. The underface is composed of a silicone film easily detachable.
 
Benefits
Substantially extends the service life of patios at low cost
Barely visible between the boards
Self-sealing around screws and nails