Green Roof Thermal Insulation

Free ventilation area of attic ventilation for every 150 sq.

Green roof thermal insulation.

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. Thermal insulation in some cases a green roof may include thermal insulation typically a layer of extruded polystyrene.

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. 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. 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. A compressive strength of 300 kpa declared in accordance with en 13164 is suitable for both green roofs and roof gardens.

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. According to etag 031 xps insulation with a cs 10 y 300 designation i e. Polystyrene doesn t sound like a green material. In climate zones 10 12 and 13 with 1 sq.

The term r value has a very specific meaning. 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. Quieter environment indoors and outdoors. Despite their rising popularity studies on green roofs thermal insulation performance are however limited.

In fact it s a form of plastic. These all factors should include enhancing the thermal benefits from the green roofs. In the winter the heat regulating effect of a sedum roof is less than in the summer because a green roof retains moisture. 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.

Of attic floor area and where at least 30 percent of the free ventilation area. In addition to thermal insulation a green roof also has a sound insulating effect. The essence of the confusion lies in the difference between insulation and thermal mass. However a green roof with grasses or herbs contributes more to heat regulation because the substrate layer is thicker than for a sedum roof.

The r stands for resistance as in thermal resistance. 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.