R Value For Flat Roof Insulation

For a 1 inch board equivalent of 6 r value.

R value for flat roof insulation.

It is top quality and the most cost effective product for your flat roof. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state local mo missouri 2012 iecc 4 r 25 5 r 25 state only mt montana 2012 iecc 6 r 30. We recommend having at least 20 r value worth of material for optimal energy efficiency. Recommended insulation levels for retrofitting existing wood framed buildings.

R value of various materials. Know exactly how much you need with our project calculators. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1. You can expect to pay about 55 100 sq ft.

Fm approved subject to the conditions of approval as a roof insulation when installed as shown in the current edition of the factory mutual research approvals guide. Existing 3 4 inches of insulation. The higher the r value the greater the insulation performance. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. R value measures how well certain building insulation materials can resist heat. R value is calculated by more than just the insulation. Add insulation to attic.

Flat expanded polystryene eps roof insulation is suitable for use with all roofing membrane materials flat eps roof insulation is compatible with loose laid and attached single ply membranes conventional built up roofing or modified bitumen systems. Minimum insulation r value requirements non residential above roof deck. To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. 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.

While expensive the best insulation is polyiso rigid foam. 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. See the department of energy s doe ranges for recommended levels of insulation below. For a very good introductory overview article on r value see r values over at the website of.

Rsi r value système international is the metric equivalent. The average r value for some common roof materials include. Flat expanded polystryene eps roof insulation provides high long term r value of eps and labor saving face laminates. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness.

R value is used in the united states.