Other materials may only have a fifty percent increase in r value when their thickness is doubled.
Foil faced rigid insulation r values.
Eps is suitable for ground contact and can be treated to resist insects.
They re much lighter and easier to work with than plywood sheets.
When used with iko aquabarrier tm tapes iko enerfoil can act as insulation air barrier and weather resistant barrier all in one.
Highest average r value per dollar about 4 6 r per inch costs the least while meeting or exceeding all required building and energy codes approved for ground contact below grade applications and can be treated to resist insects.
Ap foil provides exceptional heat moisture and air control and when installed correctly eliminates all major thermal bridges that cause heat loss.
One side has a reflective foil facer and the other side has a white non reflective foil facer to suit your building needs.
Enerfoil is lightweight easy to handle and can be sized with ease and has a high thermal r value r6 2 per inch that provides outstanding insulation protection which helps reduce energy costs.
As a foil faced polyisocyanurate foam insulation enerfoil tm s r value actually more than doubles when it is twice as thick as you can see from the chart above.
Polyiso is typically used with a foil facing and it has an r value of 7 0 to 8 0 per inch of thickness.
The foil facing also makes it very easy to seal with good quality foil faced tapes.
Eps has the lowest average r value of the three most common types of rigid foam insulation around r 4 per inch.
Johns manville ap foil faced polyiso foam sheathing boards are available in r values up to r 28 and offer a reflective foil facer on one side and a non reflective facer on the other.
Smaller sizes are also available.
This type of rigid foam usually comes with a reflective foil facing on both sides so it can also serve as a radiant barrier.
Johns manville ap foil faced polyiso continuous insulation board consists of a uniform closed cell polyisocyanurate foam core bonded on each side to a foil facer.
The reflective foil facing makes it an excellent insulation board when radiant heat is involved.
It also is the least expensive.
Products with foil facing help the panels resist moisture vapor.
Polyiso provides one of the highest r values per inch of any rigid insulation r 6 0 at 1 inch.
Highest r value per inch of any rigid board insulation does not melt when exposed to flame versus other types of rigid foam board astm e84 the low permeability of foil facing coupled with polyiso s high thermal performance make it ideal for controlling condensation in walls nominal size ranges from 47 75 to 48 25 by 95 75 to 96 25.
Known as polyiso for short polyisocyanurate foam has the highest r value per inch r 6 5 to r 6 8 of any rigid insulation.
So you need to know an insulation product s thickness as well as its r value in order to compare it to another product.