Extruded Polystyrene Insulation R Value Per Inch

For a 1 in thick 4 8 panel.

Extruded polystyrene insulation r value per inch.

Lttr per can ulc s770 03. Expanded polystyrene foam eps is the cheapest and least used foam board product on the market. R value determined by astm c518. The r value at 180 day real time age and 75ºf mean temperature is commonly used to compare products and is the value printed on the product.

This product typically has an r value of 3 6 to 4 0 per inch of thickness. 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. 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. 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.

Extruded polystyrene made from foam that is extruded through a die extruded polystyrene or xps offers impressive compressive strength along with an r value of about 5 0 per inch. Choose this option for areas that need a good amount of strength and water resistance. Also called styrofoam insulation this is the least expensive material. It provides r values that range from 3 6 to 4 2 per inch.

Performance of r 5 per inch. 2 vertical compressive strength is measured at 10 percent deformation or at yield whichever occurs first. Because of its strength and durability it is ideal for insulating below slab foundations or for below grade foundation walls. Since styrofoam brand extruded polystyrene foam insulations are visco elastic materials adequate design safety factors should be used to prevent long term creep and fatigue deformation.

The three studies reported the in service r values per inch of extruded polystyrene xps and expanded polystyrene eps insulation installed under roads and airport runways with the time in service ranging from 1 to 31 years. Xps comes unfaced or with a number of different plastic facings. Extruded polystyrene xps easily recognized by its blue green or pink color xps falls in the middle of the three types of rigid foam insulation in both cost and r value about r 5 per inch. Some products have reinforced facing to make them sturdier.