As my article states you need a minimum of about 1 5 inch of eps 1 inch of xps or 1 inch of polyiso.
2 inch layer foam roof.
Foam is especially good at the following.
All these have r values ranging from r 3 2 to r 3 8 per inch.
Spray polyurethane foam closed cell per inch of thickness.
Installed on the roof exterior foam makes the living space below more comfortable and reduces the likelihood of ice dams.
Slate roofing 3 4 inch slates.
The roofing installation team will then apply a durable outer layer to protect the foam from the elements.
Slate roofs national slate association 1926.
Foamular 150 1 in.
Slate roofs national slate association 1926.
Contractors often use it to insulate under slabs ceilings walls and roofs.
Only xps foam to be greenguard gold certified and the first xps foam certified by scientific certification systems scs to contain a minimum of 20 recycled content.
Foam board insulation is easy to use and is a great diy way to add some insulation.
R 7 7 rigid foam insulation.
In the summers here in phoenix that means that foam does a good job insulating your home and preventing heat from getting into the living spaces of your home.
The illustration shows two layers of osb or plywood roof sheathing.
Standing seam metal 0 032.
This foam is applied over the top of the membrane that came down from the roof deck catching the wall control layers.
One of the keys to over roofing is to tie the air control layer of the roof assembly to the air control layer of the wall assembly.
Note the 2 lb ft3 spray polyurethane foam enhancing the air seal around the extended rafters.
R 5 scored square edge rigid foam board insulation sheathing.
Magzo window ac foam seal tape 2 inch wide x 1 2 inch thick open cell adhesive foam tape high resilience foam insulation tape total 6 5 feet 6 5ft x 1 roll 4 7 out of 5 stars 245 13 58 13.
If you want to install rigid foam above your roof sheathing in climate zone 3 then 1 2 inch of rigid foam board is not ideal this rigid foam layer needs a minimum r value of r 5 and that s impossible with 1 2 inch of foam.
Rmax r matte plus 3 1 2 in.
R 3 2 polyisocyanurate rigid foam insulation board.
The r value of closed cell foam is r 6 5 7 per inch.
Some types of thicker foam board insulation are available but they may need to be special ordered.
More product details close rmax r matte plus 3 1 2 in.
Closed cell spray foam has a far better r value per inch than other less effective insulations like cellulose fiberglass or even open cell foam.
R 3 2 polyisocyanurate rigid foam insulation board.