R Value Of Concrete Roof Slab

By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.

R value of concrete roof slab.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. For a 6 inch slab r value would be between 0 6 and 1 2. Exterior walls with siding exterior walls with siding concrete block 8 r value concrete block 8 2 with foam insulated cores 20 with 4 on unisulated stud wall 4 3 with 4 insulated stud wall 14 brick 4 r value with 4 uninsulated stud wall 4. Calculating the inverse of that 1 r would give you a u factor in the range of 1 67 to 0 83.

The following table is in metric form. See citations at masonry below. There are many websites on the internet which have imperial building material r value numbers but not so many with metric r value numbers. This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values.

The r value of an uninsulated 8 inch thick basement wall built using normal weight concrete is 1 35 based on data from the 1993 american society of heating refrigeration and air conditioning engineers handbook. 8 thick concrete slab or foundation wall has an r value of about 1 04 30 while lightweight aggregate filled 8 thick concrete has an r value of about 2 18 30. For instance if you have a material with an r value of 12 attached to another material with an r value of 3 then both materials combined have an r value of 15. A reasonable r value for a normal concrete slab can be estimated using an r value the thermal resistance per inch of thickness between 0 1 and 0 2 and multiplying it times the slab thickness.

For a very good introductory overview article on r value see r values over at the website of. We would like to show you a description here but the site won t allow us. It uses the iso thermal planes method the same method as used in nzs4214 2006. Click here to go to our calculator to understand the real r value of a ceiling system or wall system with gaps in the insulation.

Eps based claddings directly fixed on timber framing. Some of the possible material combinations may not be suitable for actual constructions i e. Values below are some of the more common r factors for surfaces found on buildings in the u s. R value of various materials.

Concrete block 4 inch hollow core. Concrete block 8. As we said before the r value measures the thermal resistance of a material.