R Value Of Roofing Materials

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.

R value of roofing materials.

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. Click here to go to our calculator to understand the real r value of a ceiling system or wall system with gaps in the insulation. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. 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.

There are many websites on the internet which have imperial building material r value numbers but not so many with metric r value numbers. Material r inch r thick ness insulation materials fiberglass batt 3 14. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. The following table is in metric form.

Some of the possible material combinations may not be suitable for actual constructions i e. Additional r value for a masonry wall constructed using these materials needs to add the insulating value of additional wall components typically included such as 1 solid foam polyisocyanurate r 8 extruded polystyrene r 5 expanded polystyrene r 4 or 1 of perlite r 2 7 and for an exterior air film winter no wind r 0 17 an interior. To convert rsi to r value multiply the rsi by 5 67826. The average r value for some common roof materials include.

Eps based claddings directly fixed on timber framing. As we said before the r value measures the thermal resistance of a material. To calculate the r value of a roof system your contractor will take into account the underlayment coverboards adhesives insulation and even the membrane. It uses the iso thermal planes method the same method as used in nzs4214 2006.

Roofing materials asphalt shingles 0 44 wood shingles 0 97 windows single glass 0 91. This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values. R value of various materials. R value is calculated by more than just the insulation.

For a very good introductory overview article on r value see r values over at the website of. Torch down roofing peel and stick roofing asphalt roll roofing low slope roll roofing roll roofing mineral surface rolled roofing roll roofing roofing materials related products liberty 3 ft. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

R value of building materials material r inch r thick ness fiberglass inch 3 00 1 inch 4 00.