Here are some of the main building regulations that apply to fibreglass flat roofing installations.
- The roof slope must have a minimum fall of 1:80
- Part H of the building regulations regarding drainage state that water should drain to one or two edges
- Waterproofing should extend up the adjacent walls at least 150mm from the roof surface
- Cold roofs should be adequately ventilated
- Warm roofs must have a vapour control layer
- Roofs must be constructed to be wind resistant and strong enough to walk on
Summary of flat roof building regulations
A summary of the main factors relevant to fibreglass flat roofing.
Roofing Insulation: For homes or permanent residences, an insulating layer of fibreglass, polystyrene, or other material should be added on top of the roof decking. This is called the "warm-roof" model and is more effective than the cheaper "cold-roof" model, which involves placing the insulation just above the ceiling inside the building. Both models provide insulation, but the warm-roof model is more effective.
Vapour Control Layer: To attain insulation requirements in warm flat roofs requires the installation of a Vapour Control Layer (VCL). This may be composed of polyethylene membrane, bitumen sheet, polymeric foil or a simple self-adhesive sheet.
Drainpipes and guttering: Under Part H of the Building Regulations, it's obligatory to install drainpipes and corresponding guttering on at least two sides of your flat roof to prevent water from collecting at the base of your own or neighbouring buildings and avoiding any potential damage to both your property and those of your neighbours.
Joists and noggins: Flat roofs on houses need to be designed and built to be strong, durable and wind resistant. The sizing of your joists and noggins will be determined by the weight of your flat roof.
Materials: The roof should be constructed to support the weight of an average man, in order to safely facilitate maintenance.
