Roof Insulation R Value Per Inch

Building science corporation bsc and others have been examining this difference.

Roof insulation r value per inch.

To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. Provides high r value per inch in built up modified bitumen metal roof and single ply roof systems and utilizes a zero ozone depletion blowing agent that provides high thermal insulation performance. Insulation r values vary based on the type thickness and density of the insulation material. A higher r value means that the insulation will do a better job of holding in conditioned air whether that s heat in the winter or cool air in the summer.

In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. To convert rsi to r value multiply the rsi by 5 67826. Some types of insulation will have different r values for the same thickness due to differences in density and some will even increase in r value per inch as the total thickness increases. Insulation ratings are measured in r values per inch of thickness.

Contractors often use it to insulate under slabs ceilings walls and roofs. It has one of the highest r values per inch of thickness among common insulations. It performs better than other insulation types. Asbestos corrugated paper pipe insulation.

Thermal conductivity k 0 15. An r value tells you how well a type of insulation can keep heat from leaving or entering your home. Understanding r value thursday december 13 2018 what does r value mean. Used in roof wall floor below grade structural geofoam applications used most widely in insulated concrete forms and structural insulated panels highest average r value per dollar about 4 6 r per inch costs the least while meeting or exceeding all required building and energy codes.

Polyisocyanurate insulation is a common commercial and residential roof and wall insulation. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. Asbestos cement shingle siding. The r value depends on the type of material its thickness and its density.

Asbestos cement board r value. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. The r value of closed cell foam is r 6 5 7 per inch. Asbestos loose packed fibers powder.

As a benchmark one inch of solid wood has an r value of 1. Closed cell polyisocyanurate foam core. However labeled r value differs from in service r value for many insulations. All these have r values ranging from r 3 2 to r 3 8 per inch.