Flat Roof U Value 2015

Check our library of roof u value calculations.

Flat roof u value 2015. Here s my 2 cents and insulation guide for a cold flat roof concrete slab floor internal stud wall and to find out what type and thickness of insulation. Non residential above roof deck. Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated. The easiest way of getting a u value calculation is by using our free online u value calculator.

Reference table for u values u value is the coefficient of transmission i e the transmission of heat through the materials which compose the building s envelope or outer shell. 0 25 column a is for extensions where the existing dwelling s walls and roof u values are worse than 0 70 w m k in the walls and worse than 0 25 w m k in the ceiling. For example a building with material with an r value of r 11 converts to an u value of 0 09 1 r or 1 11 0 09. You should of course see the manufacturer provided technical data sheet for the r value of specific products.

The thermal transmittance or u value of the complete roof system is calculated in accordance with established international standards. U value has an inverse relationship to r value. 0 25 column a is for extensions where the existing dwelling s walls and roof u values are worse than 0 70 w m k in the walls and worse than 0 25 w m k in the ceiling. Flat epdm roof description.

Epdm rubber roof covering 19mm ply 50mm ventilated air layer protect vp400 plus lr membrane sip at specified thickness protect vc foil ultra insulating a vcl 25mm service void 50mm gyproc thermaline super. For the majority of flat roofs built up in a series of material layers each of a consistent thickness and performance the most appropriate calculation type is the combined method detailed in bs en iso 6946. U value of a 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.

For more information see our articles and how to videos below. We provide u value calculations to show compliance with current building regulations standards and best practice. R value of various materials. R value state local al alabama 2015 alabama commercial energy code 2 r 25 3 r 25 state local ak alaska 2012 alaska building energy efficiency standard 7 r 35 8 r 35 9 r 40.

Here s a handy r value table that covers most types of roof coverings building insulation and a few other materials. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. These can be supported with a detailed report.