What insulation thickness for building regulations?
It depends on the element and the target U value, not a fixed number. As a guide, modern rigid PIR board in a wall might be 100mm or more, while loft insulation is commonly 270mm or greater. Always design to the required U value.
Building Regulations set a target U value for each element rather than a fixed thickness, so the insulation needed depends on the product used and the construction. As a rough steer, achieving a wall target with rigid PIR board often needs 100mm or more, while a mineral wool loft is commonly insulated to 270mm or beyond.
The right answer always comes from a U value calculation for the specific build up and the current regulations, so treat these figures as indicative only.
Otis helps a customer choose a suitable board or roll thickness for their target, works out the quantity for the area, checks stock and prices it for the account.
General guidance for the trade. Always follow current Building Regulations, manufacturer instructions and the specifics of the job.
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