What is the minimum nib size for fire doors?

For a fire door to be fire rated, it must be fitted to a fire rated wall construction and adhere to the correct nib sizes.

The wall manufacturers will usually have minimum requirements for their wall constructions such as the minimum size nib around, between, above and below a fire rated door. These are set out in their guidance such as British Gypsums best practice guidance paper.

One of the key challenges is the layouts are usually done at Riba Stage 3, before a door manufacturer has been consulted, and this becomes very hard to change on site when the walls are being built, concrete frame poured etc.

So we’re running a Getting It Right CPD to help educate the market and ensure specifiers and contractors are building walls suitable for fire rated doors.

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