Rigid Insulation R Values Roof

R value measures how well certain building insulation materials can resist heat.

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. R value is used in the united states. 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. Most often used in roofing applications average cost of 70 per sq.

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. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. With premium polyiso manufacturing atlas is able to produce the highest effective r values with minimal material thickness. 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.

Rigid insulation is usually made up of fibrous materials or plastic foams. 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 two inches of extruded polystyrene with an r value of 11 has an rsi of 1. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826.

When it comes to insulation performance the difference is in the details. Rsi r value système international is the metric equivalent. The r value you have to achieve will be a big part of figuring out the type and thickness of the insulation you will install. 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. When new energy codes are adopted the required r value is often increased. The higher the r value the greater the insulation performance. To convert rsi to r value multiply the rsi by 5 67826.

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. Steep slope or pitched roofs will almost never include insulation as a part of the roof assembly.