Flat Roof U Value 2015

Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated.

Flat roof u value 2015.

To comply with part l of the building regulations 2010 all roofs to rooms except those in unheated buildings should be thermally insulated to a maximum u value of of 0 18 w m k. The thermal transmittance or u value of the complete roof system is calculated in accordance with established international standards. These can be supported with a detailed report. The easiest way of getting a u value calculation is by using our free online u value calculator.

R value of various materials. Flat epdm roof description. 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. 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 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. You should of course see the manufacturer provided technical data sheet for the r value of specific products. Non residential above roof deck. Check our library of roof u value calculations.

For a very good introductory overview article on r value see r values over at the website of. 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. Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated. 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.

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 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. 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.

U value of a flat roof. U value has an inverse relationship to r value. 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.