9.1.3 Internal walls and ceilings
Internal walls and ceilings shall be built to appropriate tolerances and have an acceptable finished appearance. Issues to be taken into account include:
- plastering and dry lining
- walls
- ceilings
- skirtings.
Plastering and dry lining#
Plastered and dry lined surfaces should:
- not have board joints readily visible and be within a maximum ±3mm deviation, measured using a 450mm straight edge with equal offsets
- be viewed from a distance of 2m in natural daylight with no artificial light shining on the surface. Wall lights and/or uplighters should be switched off.
Walls#
Walls should:
- be reasonably uniform, although there may be minor textural differences around lights and other fittings
- have no visible gaps between fittings and the surface (eg around switch plates)
- have jointing tape fully covered and unobtrusive in the finished surface
- have flat walls and within a ±3mm deviation measured using a 2m straight edge with equal offsets
- be a maximum of 8mm from plumb for walls up to 3m high. Taller walls should be a maximum of 8mm from plumb per storey and 12mm in total.
Ceilings#
Ceilings should be:
- level within a 3mm deviation per 1m for ceilings up to 6m across (measured at the furthest points across the full width of the ceiling)
- a maximum of 20mm out of level for ceilings over 6m across
- flat within a ±5mm deviation, measured using a 2m straight edge with equal offsets.
Setting out of corners, duct casings, access covers and any associated framing should be:
- square
- neat and tidy
- provided with an appropriate decorative finish.
Figure 10: Tolerances for external corner details
Figure 11: Tolerances for internal corner details
Figure 12: Tolerances for boxings
Also note:
- in plastered walls and ceilings, some tooling marks may be visible
- some cracking (up to 2mm wide) may occur at wall, floor and ceiling junctions, due to shrinkage and differential movement of materials
- small cracks may occur in wall finishes which pass across floors (eg in staircase walls)
- where stair strings abut a wall, a crack of up to 4mm may appear as a result of shrinkage of materials.
Skirtings#
Where skirtings are installed:
- the gap between the floor finish (without coverings) and the bottom of the skirting should not exceed 5mm at the time of completion
- joints should present a continuous appearance when viewed from a distance of 2m in daylight (some initial shrinkage of the skirting may already be evident at completion of the property).
Also note:
- the gap between the floor finish and the skirting may increase due to normal drying out, shrinkage and/or deflection, particularly in timber floors
- gaps may appear at joints and corners due to shrinkage, and between the wall finish and skirting due to drying out, shrinkage and fixing position.
Last updated: 2nd January 2024