How to insulate a roof.
Flat roof insulation regulations.
The two variations of flat roof usually flat roof constructions are defined as either cold or warm depending on how the thermal insulation is positioned in the construction.
Cold roofs and warm roofs.
The limiting u value the maximise u value which cannot be exceeded required under current building regulations for the roof is 0 20w m.
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.
It is top quality and the most cost effective product for your flat roof.
You can expect to pay about 55 100 sq ft.
Ponding can lead to premature failures in the waterproofing system and the need to refurbish an area or the entire flat roof before the end of its intended design lifetime.
This means that your approach to insulation will differ from a standard pitched roof.
Tapered flat roof insulation a flat roof should always allow for water channelling and drainage to prevent issues such as ponding.
A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value.
Building regulations for insulating a roof heat rises and therefore the building regulations requirements for heat loss through roofs are more stringent than those for walls.
Laying flat roof insulation as a rule any roof with a pitch below 10 is classified as a flat roof.
In most cases there will not be a loft in a building that features flat roofing.
There are two types of flat roof.
The removal or alteration to any roof elements could.
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.
A flat roof must be strong durable and stable throughout its lifetime.
Warm deck this is where the insulation is placed on top of the rafters joists and the roof covering is then placed over the insulation.
We recommend having at least 20 r value worth of material for optimal energy efficiency.
Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling.
In this case ventilation is required and the roof can still become wet with condensation which may cause materials to decay.
It must provide adequate protection against the elements keeping the buildings structure and interior dry.
The roof thermal insulation would normally have to be improved.
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.
For a 1 inch board equivalent of 6 r value.
While expensive the best insulation is polyiso rigid foam.
