Flat Roof Insulation Board R Value

Note from this chart that the ideal r value differs for each part of your home.

Flat roof insulation board r value.

Thermapink insulation with a variety of compressive strengths high resistance to water absorption and a stable long term r value of 5 per inch is an excellent insulation layer for use below single ply membrane roofi ng systems. Composite insulation reduces the need for a cover board when applying different membrane roof coverings. They keep your home at a comfortable temperature without the need to crank your heat. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed your attic to reach r 30 if you live in zones 2 or 3.

To convert rsi to r value multiply the rsi by 5 67826. For a very good introductory overview article on r value see r values over at the website of. 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. Rigid insulation is one of the best tools to reduce your energy costs.

Provides significantly more thermal insulation r value than wood fiber or gypsum boards. High quality rigid foam insulation that is properly installed will greatly improve ventilation eliminate drastic temperature fluctuations inside the home and protect from leaks. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. We recommend having at least 20 r value worth of material for optimal energy efficiency.

High r value 2 5 r. R value of various materials. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. This also means easy hoisting staging and maneuvering around the roof.

2020 insulation cost estimate foam board insulation prices the average cost of flat roof insulation is 0 67 per square foot for 1 inch thick polyiso with 6 r value. 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. Install it anywhere from the roof to the foundation. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. You can expect to pay about 55 100 sq ft. Rigid foam insulation also known as insulating boards provide high r values. It is top quality and the most cost effective product for your flat roof.

Composite insulation works in flat and low sloped roofs with a variety of roof coverings. For a 1 inch board equivalent of 6 r value.