Vegetated Green Roof Drainage Mat Enka Retain & Drain 3111

EnkaRetain & Drain 3111 is one of a new generation of products designed specifically for vegetated roofs. This multi-function composite consists of a 50% post-industrial recycled polypropylene drainage core of fused, entangled filaments and a specially formulated water retention fabric bonded to one side. The entangled filaments are molded into a square waffle pattern that maintains the flexible design of other Enkadrain products. The composite water retention fabric consists of a 8 oz/yd² - 100% post consumer recycled non-woven polyester fabric mechanically bonded to a 12 oz/yd² layer of synthetic hydrophilic (water) absorbent mat. The absorbent mat is designed to hold 10 to 12 times its unit weight of water. It is a very strong, durable composite that is extremely resistant to puncture and tearing. The composite is inert to biological degradation and naturally encountered chemicals, alkalis, and acids. This product can help contribute up to 2 LEED points when used in conjunction with other recycled content products. As a part of a green roof it can contribute towards additional LEED points by reducing storm water runoff, heat islands and energy consumption.

EnkaRetain & Drain 3111 Recommended Applications

Extensive green roofs
Intensive green roofs
Exterior & interior planters
Landfill caps

EnkaRetain & Drain 3111 Features and Benefits

Excellent durability
Protects waterproofing during and after placing of planting media
Conforms to irregular surfaces and offsets
Waffle design creates open flow path - even during loading of planting media
Long rolls reduce installation costs by reducing butt seams and eliminating interlocking
Recycled content polymer in core and fabric contributes towards LEED points
Provides superior water holding capacity
Reduces runoff volume in green roof applications
3" fabric overlap flap

Roof Gradient

Problems

Solutions

Steep

5-20° (9-36%)

· Runoff increases with roof gradient

· Water runs off too quickly on steep slope, growing substrate can become dry especially near the top of the roof

· Risk of sliding of green roof materials on the roof at high gradients

· Use thin profile Enkadrains (0.25”) to slow down runoff and allow time for the rain to soak into the growing substrate

· Use EnkaDrain&Retain to retain water and compensate for higher runoff

See Selection of Enkadrain products for a sloped roof here

Physical Properties

Flow Rates

Fabric Properties

Polymer Properties

Polypropylene has excellent resistance to organic solvents, degreasing agents, acids, and alkalines. It has tensile strength superior to high density polyethylene. It is has a low moisture absorption rate, is resistant to staining, and is very light weight.