American Hydrotech, Inc.,
303 E. Ohio Street, Chicago, IL 60611
Phone: 800-877-6125 Fax: 312-661-0731

Components/Parts...

The Garden Roof® Assembly combines Hydrotech's superior waterproofing technology with a system of drainage/water retention components. 

The following components are installed, working from the roof deck on up...

Roofing Membrane - Monolithic Membrane 6125EV® is a hot, fluid applied, rubberized asphalt produced with a minimum 25% recycled content. MM6125EV is the industry's premier waterproofing membrane, offering tenacious bond to substrate, no seams, simplified flashing details and self-sealing capabilities. MM6125EV is applied only by authorized, trained applicators. The MM6125EV is applied in two coats, with a layer of fabric reinforcement between layers, to a thickness of 215 mils.

Protection Course/Root Barrier - For extensive roofscapes Hydroflex 30 (our standard protection layer) and Root Stop work together to prevent roots from penetrating the waterproofing/roofing membrane. For intensive roofscapes Hydroflex RB a heavy-duty protection course/root barrier or Hydroflex 30 with Root Stop HD (our heavy duty root barrier) must be used. Hydroflex RB is intended for more intensive roofscapes or plaza decks which will be subject to high amounts of construction traffic or where plants with deeper and more aggressive root structures are to be planted.

Insulation/Air Barrier - Dow STYROFOAM® is a CFC free, closed cell, extruded polystyrene that exhibits high compressive strength and moisture resistance, while maintaining excellent long term insulation value. Use of insulation is optional, (not depicted) depending on the thermal value requirements of the structure.

Water Retention - Depending on the needs of the vegetation, additional water retention can be achieved through the use of a Moisture Retention Mat. Moisture Mat is composed of recycled, non-rotting, polypropylene fibers stitched through a polyethylene carrier sheet that is rolled out over the root barrier or insulation/air layer.

Drainage/Water Storage/Aeration - Gardendrain™ provides superior water drainage, water storage, and aeration to create a harmonious balance of air and water in the substrate soil. Gardendrain is available in a variety of profiles for use in extensive and intensive assemblies, and are lightweight panels of 100% recycled polyethylene, molded into specially designed retention cups and drainage channels. The unique design allows for the free drainage of excess water, achieving flow rates from 2.5 to 28 times higher than that of conventional drainage methods. At the same time, the system is engineered to promote irrigation through capillary action and evaporation into the soil/vegetation level. Gardendrain is installed loose-laid over the Moisture Retention Mat or insulation. It is easily cut to fit around penetrations, perimeters, and drains. In intensive applications, the retention cups are typically filled with mineral soil.

Filter Fabric - Systemfilter is a geotextile filter sheet made of non-rotting, non-woven polypropylene fibers. It is highly resistant to all natural acids and alkalis, and chemically neutral. Systemfilter is unrolled over the entire roof area completely covering the Gardendrain element in both extensive and intensive systems.

Soils - While the heart of the Garden Roof is the drainage/water retention elements, the most critical part of any green roof system is the soil. LiteTop® lightweight engineered soil provides a stable structure for the anchorage of the plants' root system, while remaining as light as possible to prevent excess loading of the roof structure. It also supplies essential nutrients, water and oxygen. Contact Hydrotech for soil specifics.

Vegetation - A wide variety of typical landscape/garden plants are suitable for a Garden Roof. The selection of the appropriate plants depends on the building construction, anticipated use of the roofscape, whether an extensive or intensive roofscape is desired and the local climatic conditions. Typical characteristics for plants utilized in Extensive Garden Roof assemblies include shallow root system, resistance to direct radiation, regenerative, and drought, frost and wind resistant. A much larger variety of choices are available for intensive roofscapes, including sod grass lawns, perennial flowers, shrubs and even small trees. 

Codes/Certification - Monolithic Membrane 6125EV has been approved by several testing and certification organizations, including Underwriters Laboratories (Class A rating), Factory Mutual (Class 1 Roof Cover), ISO 9001-2000 and the British Board of Agrement. Standards are currently being developed within the United States for green roofs and their components. Hydrotech's components are manufactured to be in conformance with various German construction standards (DIN, FLL, DDV) which are considered to be the benchmarks in the green roof industry.