Tolerances tables
In Build 156 Tolerances tables, we outlined some of the allowable construction tolerances for a quality result. We have now revisited this information and added some more for plasterboard and fibrous plaster, an area that can cause disagreements between contractors and clients.
A CONSTRUCTION TOLERANCE is an allowable variation in something that can be measured. This may be:
- the permitted variation from a given dimension or quantity
- the range of variation permitted in maintaining a specified dimension
- a permitted variation from location or alignment.
While these tolerances are a permitted deviation from perfect, the aim is always to be accurate when constructing and finishing a building. Taking everything to the outer tolerance limit may make achieving quality difficult for following trades.
References to MBIE in the tables refer to the MBIE Guide to tolerances, materials and workmanship in new residential construction 2015.
SITUATION | ACCURATE TO WITHIN: | REFERENCE |
---|---|---|
BUILDING SET-OUT | ||
Location on site | 15 mm of the specified location on a site plan | NZS 3604 Table 2.1 |
Deviation from vertical | 15 mm per 2-storey height (5 mm per 2.4 m) | NZS 3604 Table 2.1 |
CONCRETE SLAB ON GROUND | ||
Deviation from prescribed finished floor level | ±5 mm from finished floor level | NZS 3109 Table 5.2 |
Surface level | ±3 mm in any 3 m of length | NZS 3114 Table 3 |
ELEMENT | SITUATION | ACCURATE TO WITHIN: | REFERENCE |
---|---|---|---|
SUSPENDED FLOORS | |||
Piles | Concrete piles verticality | 13 mm per m of height (i.e. 1:75) | BRANZ |
Timber piles verticality | 10 mm of vertical in the first m above ground and within 20 mm of vertical over their total length | BRANZ | |
Driven timber piles | 15 mm of vertical for every m of length | NZS 3604 section 6.6.6.3 | |
Framing | Floor plane levelness | A slope of no more than 1:200 | MBIE |
Suspended floor deflection | 1/300th of span under service loads | NZS 1170.0 | |
1/360th of span maximum (where floors are tiled) | BRANZ |
SITUATION | ACCURATE TO WITHIN: | REFERENCE |
---|---|---|
TIMBER QUALITY | ||
Bow | 15 mm in a 2.4 m length of 50 mm thick framing (35 mm for a 3.6 m long member) | NZS 3631 Table 2 |
Crook | 10 mm in a 2.4 m length of 100 mm wide framing (15 mm for a 3.6 m long member) | NZS 3631 Table 3 |
Twist | 5 mm per 100 mm of width in a 2.4 m length of 50 mm thick framing (10 mm for a 3.6 m long member) | NZS 3631 Table 5 |
TIMBER ROOF FRAMING | ||
Vertical elements | Deviation of 5 mm for every 2.4 m rise in height | NZS 3604 Table 2.1 |
Horizontal elements | Deviation of 5 mm in lengths up to 10 m; 10 mm in total for any length over 10 m | NZS 3604 Table 2.1 |
TIMBER WALL FRAMING | ||
Deviation from: | ||
| 15 mm maximum | NZS 3604 Table 2.1 |
| 5 mm for lengths up to 10 m; 10 mm in total for lengths over 10 m | NZS 3604 Table 2.1 |
| 5 mm for lengths up to 10 m; 10 mm in total for lengths over 10 m | NZS 3604 Table 2.1 |
| ≤6 mm gradual bow at mid-height under 3 m long horizontal straight edge | NZS 3604 Table 2.1 |
Inter-storey relative displacement of loadbearing walls | 5 mm for vertical alignment | NZS 3604 Table 2.1 |
Permitted bow in studs at right angle corners | 2 mm in 2.4 m in both studs | NZS 3604 Table 2.1 |
Permitted bow in studs | ≤6 mm gradual bow in 2.4 m | NZS 3604 Table 2.1 |
Verticality of frames | 5 mm for every 2.4 m rise in height | NZS 3604 Table 2.1 |
Alignment of wall framing | 1.5 mm for every 1.3 m or 6 mm over 3 m using horizontal straight edge at mid-height | NZS 3604 Table 2.1 |
TIMBER FLOORING | ||
Finished floor | Slope no more than 1:200 | MBIE |
5 mm maximum deviation from level in any 10 m length; 10 mm in total for lengths over 10 m | MBIE | |
Flooring – individual sheets or boards | Flat and straight to within ±6 mm for every 3 m of length | MBIE |
SITUATION | ACCEPTABLE | REFERENCE |
---|---|---|
FIXINGS | ||
Popping visible from normal viewing at handover (level 4 or 5 finishes) | No | MBIE |
Popping that breaks the surface | No | MBIE |
Popping of fixings (outline visible under the finish) occurring over a period of time after handover but not visible from normal viewing position | Yes | MBIE |
FINISH | ||
Blistering or peeling of compounds to substrate or between coats | No | MBIE |
Finish of flush-stopped lining does not meet level of finish specified (level 4 is the default level of finish unless otherwise specified in the contract) | No | MBIE |
CRACKS | ||
Cracks visible from normal viewing position (level 4 and 5 finishes) | No | MBIE |
Fine cracks ≤0.5 mm not visible from normal viewing position (fine cracks may be expected within the first 12 months) | Yes | MBIE |
Unrepaired cracks >0.5 mm, (for example where stair stringer abuts wall lining) | No | MBIE |
JOINTS | ||
Joints between wall and ceiling and between ceiling linings – not the same level of quality as surrounding surfaces | No | MBIE |
Joints between sheets clearly visible from normal viewing position at handover in flush-stopped wall or ceilings of level 4 or higher finishes | No | MBIE |
Note: The normal viewing point for painted non-concrete wall surfaces is standing at a distance of ≥2 m (see MBIE’s Guide to tolerances, materials and workmanship in new residential construction 2015).
Note
This replaces the older Build 156 Tolerances tables.
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Articles are correct at the time of publication but may have since become outdated.