Flat Roof Insulation Board R Value

The average cost of flat roof insulation is 0 67 per square foot for 1 inch thick polyiso with 6 r value.

Flat roof insulation board r value.

Working with home insulation boards insulation panels typically come in 4x8 foot sheets. Minimum insulation r value requirements non residential above roof deck. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. Thickness inches r value in i p imperial rsi r value in metric 0 5.

For a very good introductory overview article on r value see r values over at the website of. R value measures how well certain building insulation materials can resist heat. Conditioned per atsm c1289 test method astm c5181 2. Closed cell polyisocyanurate foam technology provides additional insulation value r value of 2 5 with lightweight and low water absorption characteristics.

High quality rigid foam insulation that is properly installed will greatly improve ventilation eliminate drastic temperature fluctuations inside the home and protect from leaks. You should of course see the manufacturer provided technical data sheet for the r value of specific products. R value chart for enerfoil tm rigid foam faced insulation. You can expect to pay about 55 100 sq ft.

To convert rsi to r value multiply the rsi by 5 67826. The higher the r value the greater the insulation performance. For a 1 inch board equivalent of 6 r value. Combining different types of insulation to increase r value.

Here are the best insulation materials along with prices features and r values. Products with foil facing help the panels resist moisture vapor. We recommend having at least 20 r value worth of material for optimal energy efficiency. High density polyisocyanurate foam core.

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. Know exactly how much you need with our project calculators. This material offers the highest r values about r 6 to 6 5. 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. Smaller sizes are also available. For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. R value of various materials.

2020 insulation cost estimate foam board insulation prices. 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.