Minimum Insulation On A Flat Roof

Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling.

Minimum insulation on a flat roof.

Cold roofs and warm roofs. The target should be to achieve a u value of 0 25w m2k or better. The definition of a flat roof according to bs 6229 is having a pitch less than 10 o to the horizontal. 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.

Flat roof hello there s a lot of good material in this post for comment. We recommend having at least 20 r value worth of material for optimal energy efficiency. Gropius and le corbusier in the 20s sought to capture the machine age by using industrial style roofs. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.

It is top quality and the most cost effective product for your flat roof. However some in the industry would consider up to 15 o as their definition of a flat roof. Minimum insulation r value requirements non residential above roof deck. While expensive the best insulation is polyiso rigid foam.

For a 1 inch board equivalent of 6 r value. If you are upgrading the roof to meet current thermal requirements then the thickness of insulation will vary depending on its thermal conductivity. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. In this case ventilation is required and the roof can still become wet with condensation which may cause materials to decay.

13 july 2017 kingspan insulation uk. U value of a flat roof 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 typical u value of an existing uninsulated flat roof is 1 5w m2k. 120mm of kingspan tr26 or similar will make the.

Let me just mention that the flat roof as a motif certainly predates 1933. There are two types of flat roof. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation.