TREMDrain NW is a two-layer drainage mat consisting of a polystyrene core and nonwoven, needle-punched polypropylene fabric. TREMDrain NW provides an economical solution for single-sided subsurface drainage applications requiring a typical non-woven filter fabric bonded to a lower compressive strength and moderate flow capacity formed core.
The use of a Tremco drainage mat provides the following advantages: 1. The water flow rate is equal to or better than the aggregate backfill.
2. Aggregate backfill needs to be trucked to the site and the dirt backfill hauled from the site. With drainage, both of these procedures are eliminated.
3. Aggregate adds additional weight-bearing to the foundation wall. Drainage mat does not.
4. Drainage mat allows for full head-to-footer flow of water.
5. Drainage mat can be fitted with outlets and drainage accessories to further move the water away from the structure.
Contractors have successfully used daubs of the Tremco membrane originally used to waterproof the foundation. Insulation hangers may be set into wet daubs of Tremco membrane. 3M Holdfast 70 M has been independently evaluated by 3M and Tremco below-grade waterproofing membranes are listed as compatible on their web site. Backfilling should commence as soon as possible after installation of the drainage mat.
Drainage mat is principally designed to reduce hydrostatic head pressure and direct water to a perforated drainage system. A protection course is a puncture-resistant material designed to minimize or prevent possible damage to the waterproofing membrane prior to or during concrete pour and backfilling.
