When using rigid insulation in residential and commercial properties the most common boards used would be polyiso polyisocyanurate eps or xps each type of insulation board are very different and carry different r values and compressive strength.
Type 3 type 4 rigid insulation.
R 15 scored squared edge rigid foam board insulation sheathing.
For a 1 in thick 4 8 panel comes unfaced or with a number of different plastic facings.
R 3 graphite radiant barrier wall insulation kit 9 sheets kit multipurpose high density insulation kit r10 2 3 8 in.
Greenguard type 4 xps insulation board comprises 1 2 to 3 thick closed cell polystyrene xps with a minimum compressive strength of 30 psi.
Products with a higher r value have a higher cost but have an increased capacity to resist heat flow and therefore provide greater insulation.
Foamular 250 3 in.
It provides r values that range from 3 6 to 4 2 per inch.
Also called styrofoam insulation this is the least expensive material.
Falls in the middle of the three types of rigid foam insulation in both cost and r value used most in walls or below grade applications recyclable and at about r 5 per inch costs around 42 per sq.
Each type comes with unique advantages.