Rigid Foam Insulation R Value Per Inch

Eight inches of poor quality insulation may have a higher and better r value than one inch of top quality insulation.

Rigid foam insulation r value per inch.

This product typically has an r value of 3 6 to 4 0 per inch of thickness. Rigid insulation is usually made up of fibrous materials or plastic foams. For a 1 in thick 4 8 panel comes unfaced or with a number of different plastic facings. Because rigid foam plastic insulation products are not all aged in accordance with the same standards it is useful to publish comparison r value data.

The time of testing. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. 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 real. 4 8 7 21.

So you need to know an insulation product s thickness as well as its r value in order to compare it to another product. 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. 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. 8 3 4 4 8 2 20.

Phenolic foam spray insulation. Some products have reinforced facing to make them sturdier. 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. It provides r values that range from 3 6 to 4 2 per inch.

It provides about r 5 per inch. Corrosion problems when in contact with steel roofing moisture. R 0 77 30 phenolic foam insulation r values. Unfaced 1 in thick xps has a perm rating of around 1 making it semipermeable.

Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. Traditional loose fill insulation such as fiberglass or cellulose has an r value between r 2 0 and 3 5 per inch of thickness. For example a wall with 3 fiberglass batting r value of 10 8. The same insulation will hold more heat the thicker it is installed.

Also called styrofoam insulation this is the least expensive material. Choose this option for areas that need a good amount of strength and water resistance. 4 5 21. Rigid insulation r value by comparison usually ranges from r 4 0 to 6 5 and may get as high as r 8 7 depending on the insulation material.