Reflective Roof Systems:
Cool Roofs have been Green Roofing's biggest step forward in the area of solar reflectivity by reducing radiant heat gains through the choice of solar reflective surfaces. Through studies, large sprawling cities like Atlanta have become known as “heat islands” because of the amount of radiant heat that is absorbed from the sun by its structures, streets and parking lots. When chosing a roofing system the exterior surface of that roofing system can determine whether or not your buildings going to absorb or reflect the sun’s rays. In the last few years light colored TPO, PVC and Granulated Modified BUR roofing membranes have increased their market share significantly based on their reflective quality, and have become known as “Cool Roofs.”
Reflective Roof Coatings:
For existing smooth or granulated Built-Up-Roofs, a good quality final coat of “Aluminizer” (silver in color) not only offers excellent reflection of the sun’s rays, but will also slow the depletion of oils from the roofing system’s membrane, extending the life of the roof and lowering the radiant heat gain, reducing cooling costs.
Existing single ply roofs - mechanically attached and fully adhered systems - can be clean then coated with reflective coverings reducing radiant heat gains.
The emergence of new Roof Coatings are being driven by the immediate impact coatings can have on reflecting solar rays, reducing radiant heat gains. A building owner can immediately reduce their cooling costs and help reduce their communities heat gain by simply coating their existing roof with a good quality reflective surfacing without the expense of re-roofing their building.
Garden Roofs offer environmentally safe and helpful qualities. Garden roofs reduce heat absorption as well as reduce water run-off. In cities where rain can turn into flash flooding because of their massive amounts of hard surface areas (parking lots, large buildings, and streets), garden roofs can be used to absorb precipitation. One of the more impressive benefits to a garden roof is the water run-off that does occur has been tested and found to be less toxic, carrying with it fewer pollutants than what drains from traditional roofs, aiding the environment. When done correctly garden roofs require special layers of materials to protect the roofing membrane and the drainage system. When required, root barriers, drainage & retainage mats, as well as filter fabrics and perforated sheet-metal trim & components help protect the roofing and drainage system from the garden roof's media (overburden) by containing the soil and plants and allowing the entire assembly to drain correctly.
“Extensive Garden Roofs" have soil depths (media or medium) of 5-inches or less; anything above 5-inches is called an “Intensive Roof Garden." Plant stock comes in clippings, plugs or sod.
"Tray Systems" come complete with all the components necessary for a garden roof; they are simply installed side by side in different widths and lengths (2’ x 2’, 2’ x 4’ as well as others) but are typically 4-inches deep. Tray systems are based on the thought that should you ever have a problem with your roof you can remove the trays more easily than other roof garden systems to inspect the roofing/waterproofing.
The most important component of a properly designed roof garden is a quality roofing system under it. The garden means nothing if you’re tearing it up while trying to find leaks. Boone Brothers has installed extensive, intensive and tray systems successfully. Allow your roofing contractor to oversee the garden portion of your garden roof, or, at the very least allow your roofing contractor to oversee your garden contractor to insure the roof is protected at all times (from shovels etc) and you’ll have your priorities in their proper order.
Differing designs of Garden Roofs are as endless as the weight your building can support. The type of Garden Roof right for your building depends on the weight load that your structure is rated for. Always consult a professional engineer if you are unaware of your structures limitations before beginning design.