Flat Roof Insulation Board R Value

To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826.

Flat roof insulation board r value.

Rigid insulation is one of the best tools to reduce your energy costs. You can even place it under the foundation slab. Rigid foam insulation also known as insulating boards provide high r values. Composite insulation reduces the need for a cover board when applying different membrane roof coverings.

We recommend having at least 20 r value worth of material for optimal energy efficiency. For a very good introductory overview article on r value see r values over at the website of. 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. R value of various materials.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. Note from this chart that the ideal r value differs for each part of your home. 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. High r value 2 5 r.

It is top quality and the most cost effective product for your flat roof. For a 1 inch board equivalent of 6 r value. Combining different types of insulation to increase r value. To convert rsi to r value multiply the rsi by 5 67826.

High quality rigid foam insulation that is properly installed will greatly improve ventilation eliminate drastic temperature fluctuations inside the home and protect from leaks. This also means easy hoisting staging and maneuvering around the roof. You can expect to pay about 55 100 sq ft. They keep your home at a comfortable temperature without the need to crank your heat.

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. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. Install it anywhere from the roof to the foundation. 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.

For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. 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.