R Values Of Roofing Materials

An insulating material s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or r value defined as ft f hr btu.

R values of roofing materials.

3 85 per inch polyiso. The higher the r value the greater the effectiveness of the insulation. Pitch angle of roof the pitch of the roof angle can be a considerable factor when replacing your roof. The material offers the highest r value on the market and has no fasteners in the surface to allow thermal bridging.

Because the system is spray applied and adheres directly to the roof surface no fasteners are required. Other materials can be reflective including restoration coatings and most single ply systems but this is not the same as being a good insulator. The higher the r value the greater the insulation performance. The r value depends on the type of material its thickness and its density.

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. Or area temperature difference time heat loss. 10mm 13mm 07 077. R value per inch ft f hr btu rsi per millimeter k m w r value for typical installed thickness not per inch source.

Air film interior ceiling 14. R value measures how well certain building insulation materials can resist heat. Air film interior wall 14. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation.

In construction the r value is the measurement of a material s capacity to resist heat flowfrom one side to the other. 5 0 per inch eps insulation. When determining how much insulation you need don t guesstimate calculate. Material thickness r value m2k w permeability 50pa notes.

R value of building materials material r inch r thick ness fiberglass inch 3 00 1 inch 4 00 inch 6 00 extruded polystyrene inch 3 75 1 inch 5 00 1 inch 7 50 foil faced polyisocyanurate inch 5 40 1 inch 7 20 1 inch 10 80. Without a doubt sprayed polyurethane foam will provide the highest r value and best insulation for your flat roof replacement. R value of roofing materials and building insulation. Built up roof membrane gravel surfaced membrane and gravel only 0 33.

Here s a useful r value calculator for roofs. National roofing contractors association. The average r value for some common roof materials include. Know exactly how much you need with our project calculators.