Rigid Insulation R Values Roof

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 time aged as mandated by astm c578 and a method of accelerated aging sometimes called long term thermal resistance lttr per can ulc s770 03.

Rigid insulation r values roof.

Resources johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. Owens corning insulation products help improve thermal performance and control moisture in commercial institutional and. R value is used as a measurement of the effectiveness of thermal insulating materials. Foamular xps roof insulation for commercial buildings page 5 foamular xps roof insulation for commercial buildings foamular xps insulation is a rigid foam insulation which meets the needs of today s design professionals for a truly sustainable insulation product.

The higher the r value the better a material performs as a thermal insulator. 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. Rsi r value système international is the metric equivalent. Know exactly how much you need with our project calculators.

I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. R3 r18 r21 total roof r value. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. The increase r21 r3 exactly 18 the value by which you are increasing the r value.

Rigid foam insulation packs a lot of r value into a thin package but not all rigid foam performs the same. When determining how much insulation you need don t guesstimate calculate. R value measures how well certain building insulation materials can resist heat. To convert rsi to r value multiply the rsi by 5 67826.

R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems. The higher the r value the greater the insulation performance. Let s use the r value of iko s polyiso insulation enerfoil tm as an example. The lttr a 15 year time weighted average r value is largely affected by thermal aging where air diffuses in and blowing agent diffuses out of the foam.

The thicker the foam core the slower the diffusion and thermal aging which is why the r inch increases with thicker board.