Roof Insulation R Value Chart

The following table provides typical r values and rsi for various materials these r values were taken from manufacturer technical data sheets and are the reported r values per inch of actual products.

Roof insulation r value chart.

Recommended home insulation r values. The common denominator among varieties of insulation is the r value. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. The table below shows what levels of insulation are cost effective for different climates and.

Polyiso is the industry s premier roofing 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. You should of course see the manufacturer provided technical data sheet for the r value of specific products. In q4 2013 jm will modify its packaging to reflect lttr values by both test methods.

R3 r18 r21 total roof r value. For a very good introductory overview article on r value see r values over at the website of. 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. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value. Jm s wall sheathing line ap foil and ci max are not governed by lttr test methods and have different r value measurement standards. R value is a measure of insulation s ability to resist heat traveling through it. Tapered polyiso minimizes the negative.

Insulation level are specified by r value. To learn more about r value see roof online s r value page. Understanding r value thursday december 13 2018 what does r value mean. As a benchmark one inch of solid wood has an r value of 1.

I calculate insulation resistance to heat loss or r percentage improvement always as relative to the original number. The increase r21 r3 exactly 18 the value by which you are increasing the r value. Polyiso insulation thickness r value chart. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and.

Calculate percent improvement in r value. Achieving greater r values in attics. It can be attached using a variety of methods and is compatible with all of carlisle s single ply systems. Carlisle s tapered insulation helps promote rooftop drainage while providing excellent insulating value.

Jm sheathing r values will not change. As an example a 1 board label will include information from lttr s770 03.