Drainage composites relieve hydrostatic pressure on below-grade walls and move water off plaza decks to drains. The fabric keeps soil out of the flow channels while the core keeps an open path. They double as membrane protection. They must connect to a footing drain or deck drain, or they simply collect water against the membrane.
Drainage composite runs down to the footing drain, so don't let the fabric fold over and block the outlet.
Also heard as
- drain mat
- drainage board
- dimple board
- geocomposite
Related terms
Protection board
A rigid sheet laid over a finished membrane so backfill, rebar and foot traffic cannot puncture it.
Hydrostatic pressure
Pressure from standing groundwater against a wall or slab, rising with the depth of water above that point.
Plaza deck
A waterproofed structural slab over occupied space, topped with pavers, soil, planters or a wearing slab.
Positive side
The face of a wall or slab that touches the water source, where waterproofing works best.