Gypsum Roof Deck R Value

R value is used in the united states.

Gypsum roof deck r value.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. The tables show a u value r value and c value for several thicknesses of siplast roof insulation systems. Extruded expanded polystyrene insulation is.

R values 28 tested in accordance with astm c518 spannings. Does not consider presence absence of reflective barriers. 1 4 dens deck roof board. To convert rsi to r value multiply the rsi by 5 67826.

As we said before the r value measures the thermal resistance of a material. The u value includes the thermal resistance values for roofing and both inside and outside air films in addition to the insulation material. Does not consider directions of heat flow up or down nor winter summer conditions. These fibrous decks generally have a gypsum like or cementitious binder and combine the functions of a roof deck thermal insulation and finished ceiling.

Carpet fibrous pad 2 08 rubber pad 1 23 roofing materials asphalt shingles 0 44 wood shingles 0 97 windows single glass 0 91 w storm 2 00 double insulating glass inch. They also have acoustical value and are oftentimes used in schools and restaurants. The amount shown is an average amount used for roof system r value calculations. Does not consider internal convection effects.

A u value incorporates the total system approach to insulation design. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. Gypsum board drywall inch 0 45 inch 0 56. 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 example two inches of extruded polystyrene with an r value of 11 has an rsi of 1. R value of various materials. 40 178 weights nom. R value of building materials material r inch r thick ness fiberglass inch 3 00.

Densdeck roof boards can replace any generic type x gypsum board in any roof assembly in the ul fire resistance directory under the prefix. Rsi r value système international is the metric equivalent. For a very good introductory overview article on r value see r values over at the website of.