Minimum Roof R Value For Tapered Insulation

Since a tapered insulation system will increase thickness away from the low points the overall system r value will.

Minimum roof r value for tapered insulation.

R 20ci r 25ci r 25ci r 30ci r 30ci r 30ci r 35ci r 35ci question. For a very good introductory overview article on r value see r values over at the website of. R value of various materials. This bulletin presents the theory and calculation methods used to develop tables of effective r values for tapered insulation.

Tapered roof insulation systems are designed to provide a 1 savings vary. Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. How does this affect r values on a tapered insulation system. The r values shown above are the minimum r values required to meet code requirements.

One area where effective u values are commonly misunderstood is tapered insulation for low slope roofs or at the eaves of sloped roofs. Standard material is johns manville enrgy 3 tapered and flat polyisocyanurate roof insulation. When correctly installed tapered insulation helps eliminate problems due to ponding water and can extend the longevity of your low slope roofing system. 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.

Thermapink tapered roof insulation provides a thermally effi cient moisture resistant positive drainage slope for use under single ply or other types of roofi ng systems. Slope cross sections published feb. Find out why in the seller s fact sheet on r values. The goal of tapered roof insulation systems is to eliminate ponding standing water on a membrane when the roof deck does not provide adequate slope.

You should of course see the manufacturer provided technical data sheet for the r value of specific products. A properly designed tapered roof insulation system not only provides the necessary r value and the support for the roof system but it helps extend the. The standard tapered panel size is 4 x 4. It is readily available in the two most popular and efficient tapers 1 8 3 18 mm per foot 305 mm 1 and 1 4 6 35 mm per foot 3 18 mm 2.