Roof Insulation R Value

The percentage increase increase increase original number 100.

Roof insulation r value.

National roofing contractors association. 135 divided by k value 0 04 r value 3 37. The table below shows what levels of insulation are cost effective for different climates and locations in the home. Built up roof membrane gravel surfaced membrane and gravel only 0 33.

Insulation level are specified by r value. This is simple terms r value is measured in meters squared kelvin per watt m2k w for example let s say we have aerolite insulation that is 135mm thick and the insulation has a k value 0 04. Insulation r values vary based on the type thickness and density of the insulation material. R value per inch ft f hr btu rsi per millimeter k m w r value for typical installed thickness not per inch source.

Products can be used on wood steel framing or concrete walls. The higher the insulation r value the greater the insulating power. R value of roofing materials and building insulation. Add the results for all the materials together to get the total r value for the roof assembly.

The products are easy to handle score cut and install and no special tools are needed. What r value do i need. I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. So if the roof insulation is 145mm thick you will multiply 145 k value r value.

To calculate the total r value of a roof assembly find the total thickness in inches of each type of insulating material within the system. A higher insulation r value usually means a higher price point as well. Products provide superior insulating properties. Proper commercial roof insulation is important especially with ever increasing thermal performance requirements.

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. Insulation is identified and labeled by r value. The increase r21 r3 exactly 18 the value by which you are increasing the r value. For each different material multiply the thickness by the standard r value per inch for that material.

R value is a measure of insulation s ability to resist heat traveling through it. R stands for resistance to heat flow. 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. Recommended insulation levels for retrofitting existing wood framed buildings.

The higher the r value the better the thermal performance of the insulation. You ll see insulation r values indicated on product packaging and often on the product itself.