Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.
Green roof assembly r value.
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.
The branz house insulation guide provides construction r values for common construction types.
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.
Vegetated roof components and growing medium should not be relied upon for effective or consistent thermal resistance heat gain heat loss.
Plants need water to grow so the green roof is designed to retain some degree of moisture.
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.
Extruded expanded polystyrene insulation is commonly used in inverted roof membrane assemblies irma.
Pitched timber framed roof r 3 3.
For a very good introductory overview article on r value see r values over at the website of.
Determining insulation r value accuracy.
Completely dry growing media the dirt of the green roof so to speak has a minimal r value typically about 0 5 inch.
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.
Garden roof assembly hydrotech s garden roof assemblies combine the proven performance of our monolithic membrane 6125 roofing waterproofing with proven green technology.
However a green roof does not provide additional insulation.
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.
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.
The amount shown is an average amount used for roof system r value calculations.
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.
What r value do i need.
As we said before the r value measures the thermal resistance of a material.
Adversely u value measures the rate of heat transfer.
