Green Roof Assembly R Value

For a very good introductory overview article on r value see r values over at the website of.

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. 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. The branz house insulation guide provides construction r values for common construction types. Unlike conventional earth covered structures garden roof assemblies are lightweight and can be installed on a wide variety of new and existing structures.

Replacing the impervious surface of a conventional roof with. 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. 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. Garden roof assembly hydrotech s garden roof assemblies combine the proven performance of our monolithic membrane 6125 roofing waterproofing with proven green technology.

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. 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. As we said before the r value measures the thermal resistance of a material. The amount shown is an average amount used for roof system r value calculations.

Adversely u value measures the rate of heat transfer. Insulation thermal resistant r value requirements for the building should be integral to the roof membrane assembly below the vegetated roof components. R value of various materials. Plants need water to grow so the green roof is designed to retain some degree of moisture.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. However a green roof does not provide additional insulation. You can find some of the examples here. Pitched timber framed roof r 3 3.

What r value do i need. 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. Sprayed polyurethane foam spf will have an r value of 7 14 when it is newly installed. Determining insulation r value accuracy.

Vegetated roof components and growing medium should not be relied upon for effective or consistent thermal resistance heat gain heat loss.