Green Roof Assembly R Value

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces.

Green roof assembly r value.

Every construction design architect engineer a e knows a material s r value is an important factor when specifying insulation products with many regulations requiring minimum values for wall ceiling and roof assemblies. In an uninsulated house more heat is lost through the ceiling and roof than any other part of the house making the roof the top priority for insulation. You should of course see the manufacturer provided technical data sheet for the r value of specific products. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.

Determining insulation r value accuracy. Garden roof assembly hydrotech s garden roof assemblies combine the proven performance of our monolithic membrane 6125 roofing waterproofing with proven green technology. Pitched timber framed roof r 3 3. Extruded expanded polystyrene insulation is commonly used in inverted roof membrane assemblies irma.

R value is essentially a product s resistance to heat flow which means that the higher the product s r value the better it is at insulating the home and improving energy efficiency. You can find some of the examples here. Adversely u value measures the rate of heat transfer. For instance if you have a material with an r value of 12 attached to another material with an r value of 3 then both materials combined have an r value of 15.

Sprayed polyurethane foam spf will have an r value of 7 14 when it is newly installed. However a green roof does not provide additional insulation. What r value do i need. Completely dry growing media the dirt of the green roof so to speak has a minimal r value typically about 0 5 inch.

As we said before the r value measures the thermal resistance of a material. Replacing the impervious surface of a conventional roof with. Knowing what r value and u values mean is key to following energy codes and to selecting products that best suit the climate zone you are building in. Unlike conventional earth covered structures garden roof assemblies are lightweight and can be installed on a wide variety of new and existing structures.

Insulation thermal resistant r value requirements for the building should be integral to the roof membrane assembly below the vegetated roof components. The branz house insulation guide provides construction r values for common construction types. R value of various materials. Vegetated roof components and growing medium should not be relied upon for effective or consistent thermal resistance heat gain heat loss.

The amount shown is an average amount used for roof system r value calculations.