Flat Roof U Value 2017

Backstop u values table 1 maximum elemental u value 1 2 w m2 column 1 fabric elements column 2 area weighted average column 3 elemental u value individual element or section of element roofs pitched roof insulation at ceiling insulation on slope flat roof 0 16 0 16 0 20 0 3 walls 0 21 0 6 ground floors3 0 21 0 6 other exposed floors 0 21 0 6.

Flat roof u value 2017.

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. Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated. The thermal transmittance or u value of the complete roof system is calculated in accordance with established international standards. 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 local only az arizona no statewide mandated r values phoenix 2012 iecc yuma 2009 iecc tucson 2012 iecc flagstaff 2009 iecc 2 r 20 2 r 20 2 r 20 5 r 20 state only.

Roof coverings installed on low slope roofs roof slope 2 12 in accordance with section 1507 shall resist impact damage based on the results of tests conducted in accordance with astm d3746 astm d4272 cgsb 37 gp 52m or the resistance to foot traffic test in section 5 5 of fm 4470. U value has an inverse relationship to r value. 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. All structural metal roofing systems having a thickness equal to or greater than 22 gage and all.