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.
Flat roof u value 2016.
Then simply adjust the thickness or the u value until you are happy and the calculator will do the rest.
The thermal transmittance or u value of the complete roof system is calculated in accordance with established international standards.
Providing you with instant calculations all day everyday with step by step options and hints and tips along the way the no jargon u value calculator takes you through your construction build up until each element is included.
Ecotherm s u value calculator is simple to use easy to tweak and provides an instant u value.
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.
The following table shows two different insulation options for an inverted roof in order to achieve a u value of 0 15w m 2 k.
State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1.
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.
U value has an inverse relationship to r value.
Check our library of roof u value calculations.
Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated.
Flat epdm roof description.
As with the chart the roof build up includes paving slabs a water controlling layer insulation 7 5mm holt melt waterproofing and a 200mm reinforced concrete deck.
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.
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.
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.
A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.
If you have a target u value in mind then the calculator will give you the thickness of insulation needed.
State only ca california 2016 building energy efficiency standards 2 r 25 3 r 25 4 r 30 5 r 30 6 r 30 state local co colorado 2012 iecc.
U value of a flat roof.
Column b is for other extensions upgraded existing thermal elements non exempt conservatories and conversion of unheated.
