sips-spain
R-value of common building and insulation materials
R-value/inch (2.54 cm)
construction materials (approximate)
0.20...........................common brick
0.54...........................8 inch (20 cm) hollow clay tile
0.58...........................8 inch (20 cm) hollow concrete block
0.08...........................concrete
1.12...........................cast insulating roof concrete
0.02...........................stucco
0.79...........................wood siding
1.25...........................soft wood
0.45...........................1/2 inch (13 mm) gypsum drywall
0.33...........................3/8 inch (9.5 mm) built up roof
0.94...........................wood shingles
insulation materials (approximate)
3.60 - 4.0...................polystyrene foam, molded
5.00...........................polystyrene foam, extruded
6.20...........................polyurethane foam, expanded
3.70...........................cellulose
2.70...........................Perlite
2.20...........................Vermiculite
examples:
1) A double 8 inch thick (20 cm) wall made of hollow clay tile has a total R-value of 8.64 (2 x 8 .54). Stucco adds .04 (2 x .02). The total R-value of the stucco and insulating concrete is R-8.68.
2) A standard SIPs wall panel is a 5.5 inch (14 cm) slab of polystyrene foam with an R-value of about 3.90/inch for a total of R-21.45. The foam is clad on each side by 1/2 inch (13 mm) Oriented Strand Board (OSB) with an R-value of about .5 per side or R-1 total. External siding adds 0.8 and drywall another 0.45. To get the full R-value of the wall, add the values: 21.45 + 1 + .8 + .45 = R-23.7.
Discussion
We see that the insulating capacity of the masonry wall is 2.73 times that of the masonry wall. Actually, the effective insulating value is more because moisture and air do not pass through the SIPs panels as they do in masonry construction. Further, convection currents are practically eliminated. The effective R-value of the SIPs wall would be 3-4 times that of the masonry wall, making it an ideal construction/insulating material for passive solar heat house construction.