Necessary Insulation Thickness For Roof

See the department of energy s doe ranges for recommended levels of insulation below.

Necessary insulation thickness for roof.

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 higher the r value the better the thermal performance of the insulation. With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. R value of various materials.

Insulate your attic to the recommended level including the attic door or hatch cover. You should of course see the manufacturer provided technical data sheet for the r value of specific products. The table below shows what levels of insulation are cost effective for different climates and locations in the home. If you think you re among the 90 of us homes that are under insulated 1 performing a simple insulation inspection will help you determine your insulation needs.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. R value is a measure of insulation s ability to resist heat traveling through it. This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses. 2 insulation priorities it is most important to.

Continuous insulation zones ashrae 90 1 ashrae 189 1 igcc ibc iecc 2004 2007 2010 2013 2016 2009 2011 2014 2012 2015 2009 2012 2015 0 25 1 15 20 2 15 20 25 3 15 20 25 4 15 20 302535 5 15 20 302535 6 15 20 3035 7 15 20 3540 25 8 20 3540 25 minimum r value non residential above roof deck. It takes into account the size of the sample and the overall change of temperature over time so that you can compare thermal conductivity of materials tested with plates of different temperatures or even that were tested by other methods. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation. For a very good introductory overview article on r value see r values over at the website of.

Eps is used under roofing over foundation walls and beneath siding. It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation. Having the correct amount of attic insulation can help you maintain a comfortable temperature throughout your home and help save money on your energy bills plus prevent major issues like ice dams in the winter. However if we do not include removal of old roofing you are looking at about 7 50 to 9 00 per foot of roofing plus about 2 50 to 3 00 per foot of 5 thick insulation say about 10 12 per square foot.