R Value Of Concrete Roof Slab

The following table is in metric form.

R value of concrete roof slab.

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. For a 6 inch slab r value would be between 0 6 and 1 2. Concrete block 4 inch hollow core. Some of the possible material combinations may not be suitable for actual constructions i e.

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. This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values. We would like to show you a description here but the site won t allow us. 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.

Insulated forms available. Values below are some of the more common r factors for surfaces found on buildings in the u s. It uses the iso thermal planes method the same method as used in nzs4214 2006. 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.

As we said before the r value measures the thermal resistance of a material. 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. For a very good introductory overview article on r value see r values over at the website of. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

Remember that a higher r value and a lower u factor both indicate better insulating properties. There are many websites on the internet which have imperial building material r value numbers but not so many with metric r value numbers. 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. By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.

R value of various materials. Concrete block 8. See citations at masonry below.