Gypsum Roof Deck R Value

R value of various materials.

Gypsum roof deck r value.

R value is used in the united states. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. Referred to as meps can have an r value that will vary from less than 4 00 to slightly more than 4 00. 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.

Does not consider internal convection effects. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. A u value incorporates the total system approach to insulation design. Extruded expanded polystyrene insulation is.

Rsi r value système international is the metric equivalent. Does not consider presence absence of reflective barriers. The tables show a u value r value and c value for several thicknesses of siplast roof insulation systems. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1.

The amount shown is an average amount used for roof system r value calculations. Gypsum board drywall inch 0 45 inch 0 56. As we said before the r value measures the thermal resistance of a material. 1 4 dens deck roof board.

The u value includes the thermal resistance values for roofing and both inside and outside air films in addition to the insulation material. You should of course see the manufacturer provided technical data sheet for the r value of specific products. The r 0 87 value for the first value in this air r value table subsection. 1 4 spans flute widths up to 2 5 8 flexural strengths parallel lbs.

They also have acoustical value and are oftentimes used in schools and restaurants. Densdeck roof boards can replace any generic type x gypsum board in any roof assembly in the ul fire resistance directory under the prefix. 40 178 weights nom. For a very good introductory overview article on r value see r values over at the website of.

R value of building materials material r inch r thick ness fiberglass inch 3 00. These fibrous decks generally have a gypsum like or cementitious binder and combine the functions of a roof deck thermal insulation and finished ceiling. Does not consider directions of heat flow up or down nor winter summer conditions.