Extruded Polystyrene Insulation R Value Per Inch

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.

Extruded polystyrene insulation r value per inch.

Choose this option for areas that need a good amount of strength and water resistance. Lttr per can ulc s770 03. For a 1 in thick 4 8 panel. Some products have reinforced facing to make them sturdier.

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. Xps comes unfaced or with a number of different plastic facings. Performance of r 5 per inch. Extruded polystyrene xps easily recognized by its blue green or pink color falls in the middle of the three types of rigid foam insulation in both cost and r value used most in walls or below grade applications recyclable and at about r 5 per inch costs around 42 per sq.

2 vertical compressive strength is measured at 10 percent deformation or at yield whichever occurs first. Extruded polystyrene insulation product type minimum compressive strength of 15 psi. Expanded polystyrene foam eps is the cheapest and least used foam board product on the market. This product typically has an r value of 3 6 to 4 0 per inch of thickness.

Unfaced 1 in thick xps has a perm rating of around 1 making it semipermeable. 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. Also called styrofoam insulation this is the least expensive material. R value determined by astm c518.

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. Because of its strength and durability it is ideal for insulating below slab foundations or for below grade foundation walls. It provides r values that range from 3 6 to 4 2 per inch. 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.