A ventilation gap usually 50mm should be provided between the top of the insulation and underside of the roof covering to allow the air to flow across.
Roof insulation thickness for building regulations.
Uk building regulations stipulate that a minimum depth of 270mm is required to adequately protect your home.
The thickness of insulation required will vary depending on the material you decide to use and the manufacturer s specification.
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.
This also details the thickness.
The amount of insulation has not changed over the last 14 years though so it seems an increase in the recommended amount will most likely come shortly.
Used within a bauder waterproofing system our products meet current uk building regulations part b for fire protection.
Summary of flat roof building regulations.
If you are installing loft insulation as part of a roof renovation project where more than 25 per cent of the roof is being renewed then the level of insulation should meet the standards required by building regulations approved documents.
Roof insulation thickness for building regulations will vary depending on the type of insulation used.
If you are replacing more than 25 of the roofing area then you will also need to replace the thermal insulation.
And wish to renew more than 25 of your roof space your loft insulation must also meet the standards required by these regulations.
Walls are defined by regulation 2 3 of the building regulations 2010 as being thermal elements.
The limiting u value the maximise u value which cannot be exceeded required under current building regulations for the roof is 0 20w m.
Building regulations standards set the levels of thermal insulation required when carrying out building work either for new build or refurbishment projects.
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.
Insulation can also help to limit condensation and contribute to acoustic insulation depending on the type of insulation used.
The government try to ensure the correct levels of insulation are used though building regulations specifically part l which you can access by clicking here.
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.
Different insulants have different efficiencies and performance levels which affects the thickness required to meet building regulations.
These are expressed as a u value which needs to be achieved.