Roof Insulation Board R Value

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

Roof insulation board r value.

R value is used in the united states. Rsi r value système international is the metric equivalent. High r value 2 5 r. With firestone you get one source with everything needed for any roof design.

R value of various materials. Calculate percent improvement in r value. They keep your home at a comfortable temperature without the need to crank your heat. This insulation board is probably one of the most widely used foam board insulation products in the residential construction industry.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. Commercial roof insulation recommendations zones 1 3 pima recommended r value r 20 zones 4 6 pima recommended r value r 25 zones 7 and 8 pima recommended r value r 30 all of alaska in zone 7 except for the following boroughs in zone 8. Rigid foam insulation also known as insulating boards provide high r values. 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 in your attic to reach r 30 if you live in zones 2 or 3.

Install it anywhere from the roof to the foundation. Protector hd allows easy efficient scoring cutting and snapping which permits fast tight fabrication and all in a low dust environment. The increase r21 r3 exactly 18 the value by which you are increasing the r value. Extruded polystyrene foam xps also known as blue board or pink board comes in many different thicknesses and edge profiles.

To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. A higher r value means that the insulation will do a better job of holding in conditioned air whether that s heat in the winter or cool air in the summer. R3 r18 r21 total roof r value.

Xps has an r value of 4 5 to 5 0 per inch of thickness. 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. I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Understanding r value thursday december 13 2018 what does r value mean. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems. 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. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.