How to read these tables: Select your load category, then choose your profile size. For joist-only builds, use the Joist Span column. For bearer + joist builds, cross-reference your joist span with the bearer span. Values shown as simply supported / continuous*. Minimum back span = 4× overhang. Joist spacing: 450mm centres (400mm for educational facilities).
2.0 kPa / 1.8 PL — Standard Residential
Approx 200 kg/m² — light occupancy, private residential use. Joists at 450mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 950mm / 1050mm* | 220mm |
| 60×60mm | 1700mm / 1890mm* | 420mm |
| 120×60mm | 2990mm / 3300mm* | 770mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 970mm / 1300mm* | 220mm |
| 1000mm | 820mm / 1090mm* | 220mm |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1780mm / 2390mm* | 420mm |
| 1000mm | 1500mm / 2010mm* | 420mm |
| 1200mm | 1410mm / 1900mm* | 420mm |
| 1500mm | 1310mm / 1760mm* | 420mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 3270mm / 4390mm* | 770mm |
| 1000mm | 2760mm / 3700mm* | 770mm |
| 1200mm | 2590mm / 3480mm* | 770mm |
| 1500mm | 2410mm / 3230mm* | 770mm |
| 1900mm | 2230mm / 2980mm* | 740mm |
| 2100mm | 2150mm / 2890mm* | 710mm |
2.5 kPa / 1.8 PL — Span Table Guide (Standard Residential)
~3 people per m². Joists at 450mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 700mm / 800mm* | 250mm |
| 60×60mm | 1150mm / 1300mm* | 350mm |
| 120×60mm | 2000mm / 2200mm* | 550mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 750mm / 875mm | 250mm |
| 1000mm | 680mm / 800mm | 250mm |
| 1200mm | 680mm / 800mm | 250mm |
| 1500mm | 680mm / 800mm | 185mm |
| 1900mm | 680mm / 800mm | 185mm |
| 2100mm | 620mm / 800mm | 185mm |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1150mm / 1300mm | 350mm |
| 1000mm | 1100mm / 1250mm | 350mm |
| 1200mm | 1100mm / 1250mm | 350mm |
| 1500mm | 1050mm / 1200mm | 300mm |
| 1900mm | 1000mm / 1150mm | 300mm |
| 2100mm | 950mm / 1100mm | 300mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 2000mm / 2200mm | 550mm |
| 1000mm | 1900mm / 2100mm | 550mm |
| 1200mm | 1800mm / 2000mm | 550mm |
| 1500mm | 1700mm / 1900mm | 500mm |
| 1900mm | 1600mm / 1800mm | 500mm |
| 2100mm | 1500mm / 1700mm | 500mm |
4.0 kPa / 1.8 PL — Higher Occupancy Loading
Commercial load — balconies/roof decks. Approx 400 kg/m². Joists at 450mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 870mm / 1050mm* | 220mm |
| 60×60mm | 1600mm / 1890mm* | 420mm |
| 120×60mm | 2940mm / 3300mm* | 770mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 790mm / 1060mm* | 220mm |
| 1000mm | 670mm / 890mm* | 220mm |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1450mm / 1950mm* | 420mm |
| 1000mm | 1230mm / 1650mm* | 410mm |
| 1200mm | 1150mm / 1550mm* | 380mm |
| 1500mm | 1070mm / 1440mm* | 350mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 2670mm / 3580mm* | 770mm |
| 1000mm | 2250mm / 3020mm* | 750mm |
| 1200mm | 2120mm / 2840mm* | 700mm |
| 1500mm | 1970mm / 2640mm* | 650mm |
| 1900mm | 1810mm / 2390mm* | 600mm |
| 2100mm | 1720mm / 2280mm* | 570mm |
2.5 kPa / 2.7 PL — Standard Low Height Deck
~250 kg/m². Joists at 450mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 950mm / 1050mm* | 190mm |
| 60×60mm | 1700mm / 1890mm* | 360mm |
| 120×60mm | 2990mm / 3300mm* | 670mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 910mm / 1220mm* | 190mm |
| 1000mm | 770mm / 1030mm* | 190mm |
| 1200mm | 700mm / 850mm* | 190mm (guide) |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1670mm / 2240mm* | 360mm |
| 1000mm | 1410mm / 1890mm* | 360mm |
| 1200mm | 1330mm / 1780mm* | 360mm |
| 1500mm | 1230mm / 1650mm* | 360mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 3070mm / 4120mm* | 670mm |
| 1000mm | 2590mm / 3470mm* | 670mm |
| 1200mm | 2440mm / 3270mm* | 670mm |
| 1500mm | 2260mm / 3030mm* | 670mm |
| 1900mm | 2090mm / 2800mm* | 670mm |
| 2100mm | 2020mm / 2710mm* | 670mm |
3.5 kPa / 2.7 PL — Educational Facilities
~350 kg/m². Joists at 400mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 940mm / 1060mm* | 190mm |
| 60×60mm | 1710mm / 1900mm* | 360mm |
| 120×60mm | 3000mm / 3310mm* | 670mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 820mm / 1100mm* | 190mm |
| 1000mm | 690mm / 930mm* | 190mm |
| 1200mm | 700mm / 800mm* | 190mm |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1510mm / 2030mm* | 360mm |
| 1000mm | 1280mm / 1710mm* | 360mm |
| 1200mm | 1200mm / 1610mm* | 360mm |
| 1500mm | 1110mm / 1500mm* | 360mm |
| 1900mm | 1030mm / 1380mm* | 340mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 2780mm / 3730mm* | 670mm |
| 1000mm | 2340mm / 3140mm* | 670mm |
| 1200mm | 2210mm / 2960mm* | 670mm |
| 1500mm | 2050mm / 2750mm* | 670mm |
| 1900mm | 1890mm / 2540mm* | 630mm |
| 2100mm | 1830mm / 2420mm* | 610mm |
4.5 kPa / 3.6 PL — Podium Decks & Walkways
Joists at 450mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 840mm / 1020mm* | 140mm |
| 60×60mm | 1540mm / 1890mm* | 330mm |
| 120×60mm | 2840mm / 3300mm* | 610mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 760mm / 1020mm* | 140mm |
| 1000mm | 640mm / 860mm* | 140mm |
| 1200mm | 610mm / 700mm* | 140mm |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1400mm / 1880mm* | 330mm |
| 1000mm | 1180mm / 1590mm* | 330mm |
| 1200mm | 1110mm / 1490mm* | 330mm |
| 1500mm | 1030mm / 1390mm* | 330mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 2580mm / 3460mm* | 610mm |
| 1000mm | 2170mm / 2910mm* | 610mm |
| 1200mm | 2040mm / 2740mm* | 610mm |
| 1500mm | 1900mm / 2540mm* | 610mm |
| 1900mm | 1710mm / 2260mm* | 570mm |
| 2100mm | 1630mm / 2160mm* | 540mm |
5.5 kPa / 5.0 PL — Public Areas with Trolley Access
Disability walkways. Joists at 450mm centres.
| Profile | Joist-only span | Cantilever |
|---|---|---|
| 30×60mm | 730mm / 870mm* | 100mm |
| 60×60mm | 1450mm / 1890mm* | 290mm |
| 120×60mm | 2670mm / 3300mm* | 540mm |
30×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 720mm / 960mm* | 100mm |
| 1000mm | — | — |
60×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 1320mm / 1770mm* | 290mm |
| 1000mm | 1110mm / 1490mm* | 290mm |
| 1200mm | 1050mm / 1400mm* | 290mm |
| 1500mm | 970mm / 1300mm* | 290mm |
120×60mm — Bearer Spans
| Joist span | Bearer span | Cantilever |
|---|---|---|
| 600mm | 2420mm / 3250mm* | 540mm |
| 1000mm | 2040mm / 2740mm* | 540mm |
| 1200mm | 1920mm / 2580mm* | 540mm |
| 1500mm | 1750mm / 2310mm* | 540mm |
| 1900mm | 1560mm / 2060mm* | 520mm |
| 2100mm | 1490mm / 1970mm* | 490mm |
* Continuous Span. Simply supported span is the lower value. Minimum back span = 4× overhang length. These tables are general design guidance only. Site-specific engineering may be required. PS1 certification available on request — contact ShadowDeck on 0800 742 369. Designed to NZ Building Code (AS/NZS 1170:2002, AS/NZS 1664:1997). Certified by EQ Struc Limited, Rodney Stokes CPEng 186730.