R Value Of Roofing Materials

When determining how much insulation you need don t guesstimate calculate.

R value of roofing materials.

Rsi r value système international is the metric equivalent. 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. R value measures how well certain building insulation materials can resist heat. Some of the possible material combinations may not be suitable for actual constructions i e.

When buying various insulation materials you will almost always see an r value quoted for the material. Types of roof insulation. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. Asphalt shingles wood shingles and shakes metal roofing concrete clay and fiber cement tiles natural and.

The r value of a material is its resistance to heat flow through the material. R values and heat loss. R value table for roofing materials and building insulation. The higher the r value the better a material performs as a thermal insulator.

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. The higher the r value the more insulation the material provides by limiting airflow between outside and inside the building. In construction the r value is the measurement of a material s capacity to resist heat flowfrom one side to the other. Eps based claddings directly fixed on timber framing.

R value is used as a measurement of the effectiveness of thermal insulating materials. In general higher r means more resistance to heat loss and therefore lower heating or cooling bills for the building. There are many websites on the internet which have imperial building material r value numbers but not so many with metric r value numbers. It s important to think about r value when considering your roof project because by increasing the r value you allow your roof to keep warm air in during the winter and out during summer.

In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation. It uses the iso thermal planes method the same method as used in nzs4214 2006. In this guide we ll cover the following most common roofing options. To convert rsi to r value multiply the rsi by 5 67826.

The following table is in metric form. Know exactly how much you need with our project calculators. 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 siding materials hardboard inch 0 34. The higher the r value the greater the insulation performance.