Rigid Insulation R Values Roof

For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1.

Rigid insulation r values roof.

The thicker the foam core the slower the diffusion and thermal aging which is why the r inch increases with thicker board. 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. The r value for foamular xps insulation is provided from testing at two mean temperatures 40ºf and 75ºf and 180 day real time aged as mandated by astm c578. To convert rsi to r value multiply the rsi by 5 67826.

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. Steep slope or pitched roofs will almost never include insulation as a part of the roof assembly. 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. R value measures how well certain building insulation materials can resist heat.

Know exactly how much you need with our project calculators. 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. The higher the r value the greater the insulation performance. Most often used in roofing applications average cost of 70 per sq.

R value is used in the united states. With premium polyiso manufacturing atlas is able to produce the highest effective r values with minimal material thickness. Rsi r value système international is the metric equivalent. Rigid insulation is usually made up of fibrous materials or plastic foams.

When it comes to insulation performance the difference is in the details. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. 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 a 1 in thick panel may vary based on region standard r value of r 5 8 per inch the manufacturing process starts with liquid foam not recyclable has to be sprayed against a substrate to form a rigid panel so all iso panels are faced.

All products in the acfoam polyiso roof insulation family are closed cell rigid foam insulation board flat or tapered. When determining how much insulation you need don t guesstimate calculate.