Tolerances tables

By - , Build 156

In Build 155 Within tolerance, we outlined some of the allowable tolerances to work within for a quality result. Here, we’ve summarised that information into convenient tables.

This article has now been updated and replaced by Tolerances tables in Build 184.

A CONSTRUCTION TOLERANCE is an allowable variation in something that can be measured. These 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.

Table 1
SITUATIONACCURATE TO WITHIN:REFERENCE
BUILDING SET-OUT  
Location on site 15 mm of the specified location on a site plan NZS 3604
Building footprint 1/200th of the length, up to maximum of ±5 mm of the specified dimensions NZS 3604
Location of walls within building 1/200th of the length, up to maximum of ±5 mm of the specified dimensions NZS 3604
Deviation from vertical 15 mm per 2-storey height (5 mm per 2.4 m) NZS 3604
CONCRETE SLAB ON GROUND  
Deviation from prescribed finished floor level 10 mm in any one room or space NZS 3109
Surface level ±3 mm in any 3 m of length NZS 3109
Table 2
ELEMENTSITUATIONACCURATE TO WITHIN:REFERENCE
SUSPENDED FLOORS   
Piles Concrete piles verticality 15 mm per m of height 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
  Bearers and joists to horizontal 5 mm for every 10 m; 10 mm in total for lengths over 10 m NZS 3604
Framing Bearers and joists straightness ±5 mm per 1 m BRANZ
  Bearers and joist parallelity ±5 mm per 3 m BRANZ
  Floor plane levelness A slope of no more than 1:200 MBIE
  Suspended floor deflection 1/360th of span maximum BRANZ

References to MBIE in the tables refer to the MBIE Guide to tolerances, materials and workmanship in new residential construction 2015, this is available from www.building.govt.nz.

Table 3
SITUATIONACCURATE 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
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
Twist 5 mm per 100 mm of width in a 2.4 m length of 50 thick framing (10 mm for a 3.6 m long member) NZS 3631
TIMBER ROOF FRAMING  
Vertical elements Straight to within ±5 mm for every 2.4 m rise in height NZS 3604
Horizontal elements Straight to within ±5 mm in lengths up to 10 m; 10 mm in total for lengths over 10 m NZS 3604
TIMBER WALL FRAMING  
Deviation from:    
  • position on plan
15 mm maximum NZS 3604
  • line in plan
5 mm for lengths up to 10 m; 10 mm in total for lengths over 10 m NZS 3604
  • horizontal
5 mm for lengths up to 10 m; 10 mm in total for lengths over 10 m NZS 3604
  • a flat plane across face of wall
±6 mm for every 3 m in any direction NZS 3604
Inter-storey relative displacement of loadbearing walls 5 mm for vertical alignment NZS 3604
Permitted bow in studs at corners 2 mm in any 2.4 m length NZS 3604
Permitted bow in studs 6 mm gradual bow permitted NZS 3604
Verticality of frames ±5 mm for every 2.4 m rise in height NZS 3604
Alignment of wall framing 1.5 mm for every 1.3 m or 6 mm over 3 m using horizontal straight edge NZS 3604
FLOORING  
Finished floor Slope no more than 1:200 MBIE
  5 mm maximum deviation in any 10 m length; 10 mm in total for lengths over 10 m BRANZ
  Level to within ±5 mm within a single room or space BRANZ
Flooring – individual sheets or boards Flat and straight to within ±6 mm for every 3 m of length BRANZ

Note

This article has now been updated and replaced by Tolerances tables in Build 184.

Download the PDF

Articles are correct at the time of publication but may have since become outdated.

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