Wales new dwellings.
New flat roof insulation regulations.
You are making any structural changes to the roof.
The definition of a thermal element does not include windows doors roof windows or rooflights.
The performance of the new covering will be significantly different to that of the existing covering in the event of a fire.
If you are replacing more than 25 of the roofing area then you will also need to replace the thermal insulation.
A u value of 0 55 w m k is used for cavity insulation and 0 30 w m k for internal or external wall insulation.
Insulation can be placed between the ceiling joists.
You should fully consult the regulations and the approved document and if you are in any doubt seek advice before commencing work.
If you want to carry out repairs on or re cover less than 25 per cent of the area of a pitch or flat roof you will not normally need to submit a building regulations application.
You will need approval however if.
Ventilation is required for these roofs.
You carry out structural alterations the performance of the new covering will be.
Kingspan with a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same.
Cold deck this is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.
If the new roof covering is going to be different than the old one and this will affect the roof in the event of a fire.
You are replacing repairing more than 25 per cent of the roof area in which case the roof thermal insulation would normally have to be improved.
Summary of flat roof building regulations.
The below drawing shows the u value requirements set out for new properties in the building regulations for each element walls floors and roofs.
On new build or replacement pitched roofs the ideal build up would be insulation fitted over and then between the rafters giving a big boost for airtightness image credit.
Our guides to building regulations in wales adl1a 2014 building regulations.
This will also be reflected in the energy performance certificate for your property which is a requirement for all buildings.
Warm deck the type of insulation for this is usually of a rigid type and the thickness will vary depending on the manufacturer s specifications.
Since the government laid out new thermal and insulation regulations in 2010 it has emerged that warm roof systems are the best way to meet the required standards.
