Metal Roof Foam R Value

It performs better than other insulation types.

Metal roof foam r value.

0 00 per inch of thickness. I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. Rsi r value système international is the metric equivalent. Contractors often use it to insulate under slabs ceilings walls and roofs.

It provides about r 5 per inch. I would like to add r value with 3 or 4 inches of rigid insulation on top off existing roof. The percentage increase increase increase original number 100. 6 6 per inch of thickness.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. Expanded polystyrene foam eps is the cheapest and least used foam board product on the market. Here are the r values of the most popular commercial roofing systems. The increase r21 r3 exactly 18 the value by which you are increasing the r value.

Choose this option for areas that need a good amount of strength and water resistance. On the outside is 1 rigid foam felt underlayment and asphalt shingles. R value of various materials. 0 24 per inch of thickness.

Urea terpolymer foam 4 48 rigid fiberglass 4 lb ft3 4 00 expanded polystyrene bead board 4 00. This material offers the highest r values about r 6 to 6 5. Open cell spray foam typically has an r value of 3 5 per inch and it should be noted that open cell does not form a tight air seal. The r value of closed cell foam is r 6 5 7 per inch.

This product typically has an r value of 3 6 to 4 0 per inch of thickness. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. Some products have reinforced facing to make them sturdier. 0 33 per inch of thickness.

R value is used in the united states. I have done quite a bit of research and believe the extruded closed cell polystyrene would be the way to go which would get about r5 in. For a very good introductory overview article on r value see r values over at the website of. It provides r values that range from 3 6 to 4 2 per inch.

Roofing materials asphalt shingles 0 44 wood shingles 0 97 windows single glass 0 91. R3 r18 r21 total roof r value. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. R value of building materials material r inch r thick ness fiberglass inch 3 00.

It performs much better than any form of batt for stopping air flow but it is not as complete of an air seal as closed cell spray foam. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1. Expanded polystyrene insulation is similar to the foam used for packing peanuts and it s typically used for insulated concrete forms also knows as icf s. 0 24 per inch of thickness.