Tech Update: Tolerances in Internal Walls, Ceilings, Junctions and Floors

Earlier this year we looked at acceptable tolerances in brickwork, detailing some of our technical guidance for bricks blocks and masonry. In our latest Tech Update we’re continuing with Tolerances, but this time we are going to be looking at the acceptable tolerances for several key components to the interior structure of your construction.

Walls and Ceilings

There should be no severe difference of more than 4mm in any 300mm flatness of a wall. The maximum deviation is +/- 5mm from a 2m straight edge with equal offsets, horizontally and vertically, for all wall and ceiling surfaces.


The image illustrates the maximum deviation for walls and ceilings.


Whenever there are alterations made in the construction materials used due to shrinkage and the differential movement of materials; small cracks (up to 3mm wide) may become visible in the surface at wall, floor and ceiling junctions.


Floors which are up to around 6m across can be a maximum of 4mm out of level per metre and a maximum of 25mm overall for larger spans. The effects of normal drying shrinkage on screeded floors could cause some fracturing.
It is important to note that shrinkage of timber floors and staircases is a natural occurrence when drying out and that this could result in the squeaking of materials as they move against each other. This again is a natural occurrence and cannot be eliminated entirely.


The image illustrates the maximum deviation for floors

For further information on Acceptable Tolerances you can download Chapter 1 of our Technical Manual:

The information used in this article is taken from Version 8 of the LABC Warranty technical Manual and is provided as guidance in meeting our technical standards. If working on an LABC Warranty site please check which standards apply.


Please Note: Every care was taken to ensure the information in this article was correct at the time of publication. Any written guidance provided does not replace the reader’s professional judgement and any construction project should comply with the relevant Building Regulations or applicable technical standards. However, for the most up to date LABC Warranty technical guidance please refer to your Risk Management Surveyor and the latest version of the LABC Warranty technical manual.


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