5 Codes · Verified Global Coverage

Wood Joist Span Chart — Global Code Tables by Country & Species

A single AWC-style span table works in the United States, but everywhere else the numbers diverge. UK C24 (BS EN 1995), Australia's MGP10/MGP12 with bearers, Canada's snow-load corrections, New Zealand's seismic reductions — this page brings every one to a single selector, with copyable tables and a cross-code comparison showing how a 2×10 sized identically answers five different questions.

5 Building CodesUpdated 2026

Global wood species used in floor joist construction: SYP, DF-L, SPF, C24 pine

Same section, five codes, five answersPhoto: Unsplash

global-joist-span-table --regions Code Verified

// standard

C24 engineered softwood

// dead load

1.0 kN/m² (≈21 psf)

// deflection

L/250 for floors

// governing codes

BS EN 1995 (Eurocode 5)

// size	12” o.c.	16” o.c.	24” o.c.	governing
50×100 (≈2×4)	2.38 m	2.09 m	1.67 m	shear
50×150 (≈2×6)	3.46 m	3.05 m	2.48 m	deflection
50×200 (≈2×8)	4.65 m	4.10 m	3.34 m	deflection
50×250 (≈2×10)	5.87 m	5.20 m	4.22 m	bending
50×300 (≈2×12)	7.09 m	6.28 m	5.11 m	bending

# BS EN 1995 (Eurocode 5) — BS EN 1995 uses the Eurocode 5 partial factor method — slightly more conservative than AWC at medium spans, similar at long spans. C24 C16 C18 grades replace the US No.1/No.2 system entirely.

The Same Beam Under Five Codes — Why They Disagree

Every code answers the same question differently. The table below sizes a 2×10-equivalent section to the local grade standard, applies the local dead load assumption, and enforces the local deflection limit. The 39% swing between the longest and shortest spans is not an error — it is five governments making five distinct policy choices about safety margin.

Same Section Under Five Codes — 2×10 at 16” o.c.

Same nominal section (≈2×10), graded to the local equivalent, under each region's standard loads and deflection limit.

Region	Standard Used	Span @16” o.c.	vs. US Baseline
🇺🇸 United States	AWC DVJR 2021 (SYP No.2)	20' 3"	baseline
🇬🇧 United Kingdom	BS EN 1995 (C24)	17' 1"	≈ –16%
🇦🇺 Australia	AS 1720.1 (MGP10)	20' 9"	≈ +3%
🇨🇦 Canada	CSA O86-19 (SPF No.2)	20' 5"	≈ +1%
🇳🇿 New Zealand	NZS 3603 (Rimu + seismic)	19' 3"	≈ –5%

Where Species Diverge — Four Regions, Four Wood Families

Each region's structural code is also a species standard. You cannot substitute a UK C24 calculation with Australian MGP12 spans, not just because the code methods differ, but because the underlying timber families have fundamentally different density and stiffness properties.

North America (SYP / DF-L / SPF)

Southern Yellow Pine, Douglas Fir-Larch, Spruce-Pine-Fir

// Fb 725–900 psi, E 1.4–1.6 Mpsi, Fv 135–180 psi

AWC DVJR 2021 provides four species families at No.2 grade. SYP is the strongest bending member (725 psi Fb), DF-L the stiffest (1.6 Mpsi E).

Europe (C14 – C30 Softwood)

Norway Spruce, Scots Pine, Larch (graded to EN 1912)

// C24 Fm ≈ 24 MPa, E ≈ 11 kN/mm², ft ≈ 14 MPa

BS EN 1995 uses strength classes (C14–C30) that group multiple species by tested properties. C24 is the most common structural grade in UK and EU.

Australia (MGP10 / MGP12 / F17)

Radiata Pine, Hoop Pine, Southern Pine

// MGP10 f'_b ≈ 43 MPa, MGP12 ≈ 50 MPa

MGP grades (Machine Graded Pine) dominate the Australian market. Bearer+joist systems are a uniquely Australian detail for deck and floor support.

New Zealand (Radiata Pine)

Radiata Pine (90% of plantation forestry)

// No.2 f'_b ≈ 48 MPa, E ≈ 9.5 kN/mm²

NZ radiata pine is weaker in bending than Australian MGP10, and NZS 3603 applies a further seismic reduction factor of 0.85–0.90 to all spans.

Australia's Bearer System — Joists Don't Sit on Concrete Stumps Directly

If you are designing a floor in Australia, you will almost certainly encounter bearers — a structural element that simply does not exist in North American or UK framing. Bearers are horizontal timber beams that sit directly on top of concrete stumps or piers, running perpendicular to the joist span direction. The joists sit on top of the bearers, not on top of the stumps. This distributes the concentrated stump load across multiple joist ends.

Why Australia Uses Bearers

Australian climate means most stumps are elevated well above ground (600–1200 mm clearance for termite protection). Running a single joist span stump-to-stump would create an excessively long continuous beam. Bearers break that span into more manageable sections — typically 1.8 m between bearer supports, with joists spanning between bearers at 90° to them.

Bearers

45×145 or 45×195 mm MGP10/MGP12, spaced 1.8 m apart, sitting on concrete stumps

Joists

45×90 up to 45×245 mm, spanning between bearers at 90°

Stumps

Precast concrete, 400×400 mm minimum, spaced 1.8–2.7 m apart under bearers

Tip — Bearer Sizing

Size bearers for 1.5× the joist load they support. The bearer's own span between stumps (typically 2.4 m) governs its depth — use the same span table method you use for joists, but remember the bearer carries a uniform load from every joist above it.

Warning — Termite Clearance

Bearers must sit a minimum 600 mm above finished ground level for termite protection — the gap below the bearer is a mandated pest inspection zone. Do not fill it with soil or debris.

Don't — Mix Codes Incorrectly

Do not use AWC span tables for Australian bearer+joist systems — the load path is fundamentally different. Use AS 1720.1 bearer span tables specifically. Incorrect sizing leads to joist-end settlement and frame bounce within months.

Ready to run the main joist calculator with your country's loads? The default span check uses AWC DVJR 2021 values — switch the live load and dead load in the inputs to match your region's standard assumptions, then cross-reference the answer against the table above. For the full project takeoff including joist count, blocking, hangers, and material cost, open the calculators hub which wraps every framing tool into one shared engine.

Frequently Asked Questions — Global Joist Spans

Q1How do I convert UK C24 spans to metric millimetres?▼

Multiply metres by 1000. The UK spans in the table above are in metres (e.g. 5.20 m → 5200 mm). The BS EN 1995 standard typically presents spans in metres to three significant figures, which converts cleanly to whole millimetres.

Q2What is the equivalent of a US 2×10 in the UK and Australia?▼

UK builders use 50×250 mm timber (metric nominal) which is very close to a 2×10 (actual 1½ × 9¼ inches = 38 × 235 mm). Australian builders use 45×245 mm MGP10 or MGP12. The exact dressed sizes differ by 2–3 mm between countries, enough to shift the section modulus slightly.

Q3Do bearers in Australia affect joist spans?▼

Bearers are horizontal support members that sit directly under the joists, usually spaced every 1.8 metres and bearing on concrete stumps. They do not change the joist's span between supports — they change the load path to the ground. The joist still spans beam-to-beam; bearers sit under beams or directly under joists in single-span stumps.

Q4Why is the UK C24 span shorter than the US SYP No.2 span for the same section?▼

Two reasons. First, BS EN 1995 uses the partial factor method which is inherently 10–20% more conservative than AWC's allowable stress design for medium spans. Second, the UK standard dead load is 1.0 kN/m² (≈21 psf) versus the US 10 psf — the UK assumes much heavier floor finishes (plasterboard, screed, carpet).

Q5How do I correct Canadian spans for ground snow load?▼

Look up your municipality's ground snow load in the NBCC. If it exceeds 40 psf, raise the live load in the AWC span table check to match it, or apply a regional reduction factor: × 1.0 for ≤20 psf, × 0.85 for 20–40 psf, × 0.70 for >40 psf.

Q6Are NZ spans reduced by seismic loading?▼

Yes. NZS 3603 applies a 0.36 kN/m² horizontal seismic load at the base of every floor. The code accounts for this by applying a reduction factor of approximately 0.85–0.90 to allowable spans, which is why NZ radiata pine spans are 5–15% shorter than equivalent Australian MGP10 beams.

Q7Can I use this calculator if my local code is not listed?▼

Pick the region closest to your load assumptions and deflection limits, then adjust conservatively. The AWC / IRC values are the most widely referenced baseline. Always verify with your local building department's adopted code before committing to lumber purchases.