Green Roof Thermal Insulation

In addition to thermal insulation a green roof also has a sound insulating effect.

Green roof thermal insulation.

The term r value has a very specific meaning. Despite their rising popularity studies on green roofs thermal insulation performance are however limited. The essence of the confusion lies in the difference between insulation and thermal mass. To save energy from green roofs depend on many factors such as the depth and composition of the substrate the climatic conditions plant type type of irrigation type of green roof and design insulation.

Insulation with a thermal resistance of at least 0 85hr ft2 degree f btu or at least 3 4 inch air space is added to the roof deck over an attic or 7. However a green roof with grasses or herbs contributes more to heat regulation because the substrate layer is thicker than for a sedum roof. Yet polystyrene is a fabulous insulator with r values that range from r 3 8 to r 4 4 per inch of thickness and so it s considered green because it helps save so much energy source. Unfortunately the ability of a green roof to control the flow of heat energy cannot and should not be described only by an r value not even an adjusted equivalent or approximate r value.

While this can be positioned below the roof deck installation above the waterproofing known as an inverted green roof is preferred as it further protects the membrane from condensation and physical damage. In the winter the heat regulating effect of a sedum roof is less than in the summer because a green roof retains moisture. A compressive strength of 300 kpa declared in accordance with en 13164 is suitable for both green roofs and roof gardens. Free ventilation area of attic ventilation for every 150 sq.

Rather than keeping heat from migrating through the roof assembly the green roof acts as a heat sink that soaks up and retains thermal energy. Department of energy polystyrene insulation comes in rigid foam boards that make it easy to insulate any part of a building. So you can also save on your heating bills in the winter. The basic anatomy of a green roof consists of vegetation growing medium filter membrane drainage layer waterproof root repellant layer roofing membrane support for plantings above thermal insulation vapor control layer and structural roof support.

The thermal mass effect is the most important energy related benefit of a green roof. However it cannot be used to assess eps insulation for green roofs due to the current limited history of use in green roofs and roof gardens. Quieter environment indoors and outdoors. The r stands for resistance as in thermal resistance.

In fact it s a form of plastic. Thermal insulation in some cases a green roof may include thermal insulation typically a layer of extruded polystyrene. In climate zones 10 12 and 13 with 1 sq. These all factors should include enhancing the thermal benefits from the green roofs.

Polystyrene doesn t sound like a green material. The most common request i get from architects and engineers is for the r value of a green roof system.