Polystyrene Roof Insulation R Value

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

Polystyrene roof insulation r value.

Rigid foam insulation packs a lot of r value into a thin package but not all rigid foam performs the same. For a very good introductory overview article on r value see r values over at the website of. Expanded polystyrene foam eps is the cheapest and least used foam board product on the market. Dees dated august 1984.

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. This product typically has an r value of 3 6 to 4 0 per inch of thickness. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The r value performance for eps insulation is discussed in the report report on expanded polystyrene insulation for use in built up and single ply roofing systems by rene m.

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. 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. Expanded polystyrene eps extruded polystyrene xps styrofoam tm. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

Insulfoam taper is cut from the same high quality eps as our flat insulroof products and meets or exceeds the requirements of astm c578 standard. Choose rigid insulation wisely and consider the effect its characteristics will have on the performance of the your project overall product cost and the best way to get the bang for your buck. Products provide superior insulating properties. Flat tapered eps roofing insulation insulfoam taper is an engineered insulation consisting of a superior closed cell lightweight expanded polystyrene eps.

The r value for foamular xps insulation is provided from testing at two mean temperatures 40ºf and 75ºf and from two aging conditioning techniques 180 day realtime aged as mandated by astm c578 and a method of accelerated aging sometimes called long term thermal resistance lttr per can ulc s770 03. The report shows that samples of eps insulation had no deterioration in r value. Insulfoam i vii ii ix xiv and xv. Dupuis and jerome g.

Foamular extruded polystyrene xps rigid foam insulation offers foamular extruded polystyrene xps rigid foam insulation offers a comprehensive line of products choose the strength you need from 15 to 60 psi and exceptional moisture resistance.