Question: Is the waterproofing material in your system specifically designed for green roofs or has it been adapted from another type of system?

Answer: The EnviroTech Roof System was designed specifically for green roof applications. The EnviroTech membrane incorporates a root barrier, a water retention system and waterproofing all in a single membrane. In conjunction with other specifically designed green roof system components, the membrane provides superior performance and excellent life expectancy.

Question: What root resistant standards does your membrane meet?

Answer: The EnviroTech System meets or exceeds all of today's standards set by the Din System (43k PDF) for root resistance and Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau (167k PDF) e.V. (FLL) testing for the root resistance of membranes and coatings for roof greening.

Question: How long has your Eco roof system been in use?

Answer: Green Roof systems have been used extensively in Europe for over 50 years. The EnviroTech roof system has been in use in Europe and Puerto Rico for many years. The individual components which make up our EnviroTech roof system have been used individually for a decade.

Question: Have your roofing system been exposed to any severe weather (snow, ice, freezing temperatures, droughts?)

Answer: EnviroTech roof systems have performed well in a wide range of environments. Locations of successful installations have ranged from Moscow with it's extreme cold to San Juan, Puerto Rico with it's tropical heat conditions.

Question: How complicated is the installation of your roofing system?

Answer: The EnviroTech roof system is installed in a similar fashion to most APP Modified Bitumen membranes. The convenience of having the waterproofing membrane that incorporates the root resistant material and water retention system all in one layer simplifies the installation process. Other systems require the waterproofing membrane to be installed first, then an additional layer is required for a root barrier and another layer for water retention before the soil substrate and plantings can be installed.

Question: Are the roofing details designed specifically with green roofing in mind?

Answer: Since EnviroTech green roof systems were designed specifically for green roof applications, all roofing details at penetrations, projections and terminations have been designed to take into account the plants growing on top of the roof. Our system provides all possible deterrents to keep plants and roots from growing into and behind the roofing flashings.

Question: Does your roofing membrane have root resistance built right into it? If so, what is it? Is it a chemical (i.e. herbicide)? Will the chemical leach out?

Answer: Our EnviroTech green roof system consists of two root resistant products. One is a copper foil which is laminated to the reinforcing scrim and becomes an integral part of the roofing membrane. Second, the modified bitumen contains copper exudes which will prevent the plants from penetrating the membrane. Since all the root resistant material is encapsulated in the modified bitumen, it is nearly impossible for it to leach out. Many competitive products employ a copper foil installed on top of the waterproofing membrane. This type of foil has the potential of leaching copper elements into storm water runoff and thus into ground water.

Question: What scheduled inspections and maintenance is required?

Answer: Routine inspections should be conducted similar to any other roofing system. Maintenance of the membrane should be less of an issue since most of the membrane is covered with the plants and soil. However, routine maintenance may be required for caulking of exposed edges and exposed base flashings.

Maintenance of the plantings will be determined by the type of plants used. Sedums are the most common type of plant, it is also the most maintenance free. Some clients however may choose to use a more decorative type of plant which may require additional maintenance as would be recommended by the horticulturist.

Question: Do other plants and weeds invade green roofs and do they have to be removed?

Answer: Like any ground cover, the potential for other plants and weeds to take root on the roof is present. They do not however have to be removed, unless the client finds them aesthetically undesirable. The thin layer of soil required for the EnviroTech system should discourage most weeds and unwanted plants. If other plants and weeds take root on the roof they do not threaten the integrity of the roofing system.

Question: How do you fix leaks in your system?

Answer: Maintenance of the EnviroTech roof system will be conducted similar to any other bituminous roofing system. First, the plants and soil mixture should be removed to expose the roofing membrane. Once the leaks are repaired, using conventional bituminous membrane repair methods, a layer of Famogreen RET CU P4 must be reinstalled. If vegetation mats were installed on the roof, they will be reinstalled prior to the soil and plants consistent with the original design.

Question: How thick is your membrane? How thick is the completed system?

Answer: The membrane itself varies in thickness depending on the base sheet and the cap sheet used. Our green roof system varies from a minimum of 7 millimeters in thickness to a maximum depending on the number of plies and the membrane selected. The thickness of the completed roof system can vary with the insulation required depending on location, the amount of soil needed for the type of plants selected and the plants themselves. Typically a completely saturated roof system creates a weight design consideration of approximately 15 lbs/sq ft.

Question: What is the modifier in your material?

Answer: The EnviroTech Green Roof System uses amorphous polyalphaolefin as the modifier in its membrane.

Question: Can your system be used on sloped roofs?

Answer: The EnviroTech Green Roof System is one of the few roof systems that is designed specifically to be used on extremely steep slopes, as well as low slope roofing. Typically our roof system can be installed on roofs with slopes up to 45 degrees. This is due largely to the use of a water retention system that is laminated to the top of the membrane, and vegetation mats that can be used to hold the plantings in place.

Question: How thick is the soil necessary or required in your system?

Answer: The thickness of the soil and the type of soil is dictated by the type of plants that a client would like to have installed on his roof system. The most common type of plant is the sedum variety, which is typically found in rock gardens. This plant variety is very drought and freeze resistant and requires a minimum amount of soil, as little as 1.2 inches in depth. The minimum amount of soil also helps reduce the structural load on the roof. This is an additional reason the sedum variety of plants are more popular in the United States.

Question: How much water is held in your system?

Answer: Completely saturated, the EnviroTech Green Roof System will store approximately 1.25 gallons of water/sq ft, which equates to 10.25 lbs/sq ft.

Question: What is the per square foot weight of your system fully saturated with water?

Answer: Typically the roof design and type of soil used will determine the per square foot retention rate of the system when fully saturated. Various soil mixtures will retain different amounts of moisture. Typically a roof system can be designed to weigh as low as 10.25 lbs/sq ft and hold approximately 1.25 gallons of water per square foot. As a design consideration we recommend 15 lbs. per square foot as the deadload requirement for a building structure.

Question: What amount of energy savings can be realized with the implementation of a Green Roof System?

Answer: It is very difficult to give a specific answer to this question because of the many different variables involved in the design of a roofing system. Typically, the insulation value of a roof will not be influenced by the use of a green roof system. As an example, if the energy code requirement for a roof system is R-20, that R value should be obtained by the use of rigid insulation similar to any other industrial commercial roofing system. Additional energy savings will be realized from the basic cooling effect of the green roof covering and the evaporative effect of retained moisture. The depth of the soil will provide some R value, but when it is saturated it cannot be calculated into an R value. The green roof itself by nature will absorb energy rather than reflect it due to the organic matter, color and openness of the plant medium. The cost to run mechanical equipment installed on the roof will be somewhat decreased due to the lower ambient temperature of the surface of a green roof. Surface temperatures are significantly less than those of a typical black bituminous industrial commercial roof system.

Question: How does the green roof compare in terms of cost to standard industrial commercial roofing systems?

Answer: Cost will vary depending on location of the project. Typically a green roofing system will include a variety of different layers normally not associated with commercial industrial roofing, such as a root resistant layer, a water retention layer, soil and plant layers. One of EnviroTech's unique advantages is our membrane incorporates a root resistant barrier, a water retention system and waterproofing layer all in one membrane. No additional labor is required to install additional system layers. Upon completion of the installation of the roofing system, the contractor simply installs the soil evenly over the roof and installs the plantings. The cost associated with our system is slightly higher than a typical roof system depending on the plant medium used for a particular project. However, when you consider the life cycle costing benefits of installing a green roof system you will realize over time that the green roof, which has a life expectancy of 40 years or more, is much more cost effective than any other alternative.

Question: Is there a chemical in EnviroTech Green Roof System that is banned in the US?

Answer: No chemical root barriers are included in our membrane. We use a copper foil as a root resistant barrier. Our system has written FLL approval.

Question: Is your system manufactured in the US?

Answer: Our membranes are the only product that are not. FAMOS is an ISO 9001 manufacturer with operations located in the US, and many of our products are manufactured in the US. The membranes are manufactured in Europe due to the availability of high quality asphalt and components. We can include recycled material such as granulated auto tires.