Flat Roof Extension Building Regs

The limiting u value the maximise u value which cannot be exceeded required under current building regulations for the roof is 0 20w m.

Flat roof extension building regs.

Insulating flat roof extensions. A roof is defined in bs 6229 as a flat roof if it has a pitch of 10 degrees or less. Flat roof 0 18 extensions to form conservatories the accepted definition of conservatory for building control purposes in hertfordshire is a ground level extension that is thermally separated see a. U value of a flat roof.

Building regulations for insulating a roof. Below from the dwelling and has not less than three quarters of its roof area and one half its exposed wall area made from. It must provide adequate protection against the elements keeping the buildings structure and interior dry. Flat roof 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.

Thickness varies according to the manufacturer s specifications. 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. A lower u value indicates better insulation properties hence u value requirements usually specify a maximum value. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines.

Flat roof this usually consists of felting which has a slight fall to allow rain water to drain off. To comply with part l of the building regulations flat roofs must achieve u values of 0 18 w m k or lower. Heat rises and therefore the building regulations requirements for heat loss through roofs are more stringent than those for walls. There must be a slope of 1 80.

Traditionally flat roofs were constructed with cold decks where the spaces between the joists were packed with mineral wool type insulation placed above the ceiling like a conventional loft. When installing or repairing a flat roof you must adhere to building regulations. On a basic level flat roof construction comes in the form of roofing timbers or joists as they are more commonly known or steels that are laid across two uprights walls in most cases. A flat roof must be strong durable and stable throughout its lifetime.

Part h of the building regulations regarding drainage state that water should drain to one or two edges. To enable compliance with the requirements of the building regulations to be demonstrated full details of the new roof will be needed including materials and their dimensions and performance properties.