R value of concrete block wall?

Question

i have a block construction home built in '48. the block is 4x8x12. it is not solid grouted. is there a standard R value for block? it alse has 3/4" of R-tech insulfoam under stucco on the exterior. any takers?

Answer 1

Block is not an insulating property, R value is nothing substantial. The problem with block or any other masonry product is it holds the hot/cold for long periods of time. A concrete block out in the direct sun all day will take several hours to cool off at night, the same for cold conditions.

Thus a block house soaks up the heat of a the first few days of a hot summer, but it never cools down much, thus you are trying to not only cool it down in the daytime, but also at night as it is still radiating heat.

There is granular insulation that you can pour in the block cores, however you must have access to top row of block.

They now can also drill holes in block and inject a foam insulation in the cores, this is a little pricey.

Answer 2

It is around .5 yes point five

Answer 3

R 0.71 for the 4 inch thick Concrete blocks

Boards,     Cork board is R3.70 per inch

                   Polystyrene is R3.60 per inch

                   Polyurethane  R5.90 per inch