Eps is used under roofing over foundation walls and beneath siding.
Eps in attic.
It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation.
Eps is by far the most versatile of the three rigid insulation options.
To do that without creating soggy roof sheathing from wintertime moisture accumulation in us climate zone 6 you need a minimum of half the total r value to be on the exterior r25 in exterior foam out of a total code min r49.
This is the same stuff your disposable coffee cup and is made out of and it s used to protect fragile items in their packaging.
Eps is made of 98 trapped air and only 2 plastic making it an efficient insulator with a small amount of raw material.
This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses.
Use eps to increase r value in the attic within wall cavities or on the roof but avoid using this product below grade unless it s protected by a moisture resistant film or coating.
It can be applied on the roof floor and walls and it s most widely used in structural insulated panels and insulated concrete forms.
Let s have a look at what rigid foam is and the different types some tips on installing it and special considerations to keep in mind.
In new construction the best use of eps in attics would be to put in on the exterior of the roof deck making it a conditioned attic.