MGP10SpanTables
The MGP10 library

MGP10 Span Table Guides

From what the grade means to reading the tables, deflection, load width, wind classification, and the mistakes that undersize a frame.

A length of pine stamped with the MGP10 stress gradeMGP10Machine Graded Pine — every piece is stamped with its stress grade

What Is MGP10? Machine Graded Pine Explained

MGP10 is a machine-graded pine stress grade used across Australian timber framing. Here is what the grade means, how it compares to MGP12, MGP15 and F-grades, and where it is used.

Diagram of a timber beam spanning between two supports under loadSpan (L)Load ↓  ·  Deflection (δ) · Support reactionsThe span is the clear distance a member bridges between supports

How to Read MGP10 Span Tables (Step by Step)

MGP10 span tables look intimidating but follow a clear logic. Learn the inputs you need — member, size, spacing, span type, wind class, load width — and how to find the right value.

Floor joists laid across two bearers at regular spacingFloor joists span across bearers, set out at regular spacing (e.g. 450 or 600 mm)

MGP10 Floor Joist Spans

How MGP10 floor joist spans work — the role of spacing, single vs continuous span, deflection and load, plus why decks are a different case. A practical orientation, not a number to copy.

A bearer on posts carrying floor joists, showing floor load widthFloor Load Width (FLW)Bearers carry the joists; their span depends on Floor Load Width and post spacing

MGP10 Bearer Spans and Floor Load Width Explained

Bearers carry the joists, and their span depends heavily on floor load width. Learn how bearers, joists and posts work together and how to approach an MGP10 bearer span lookup.

Roof rafters spanning from a ridge under roof loadRafters span from ridge to wall; sizing depends on Roof Load Width, roof mass & wind

MGP10 Rafter and Roof Member Spans

Roof members add roof load width, roof mass and wind into the mix. Learn how MGP10 rafter and roof beam spans are determined and which inputs you must get right.

A lintel spanning over a wall openingOpening (door / window)A lintel carries the load above an opening across to the supports each side

MGP10 Lintels and Beams

Lintels carry the load above doors and windows. Learn how MGP10 lintel spans are approached, why point loads change everything, and when you need an engineered beam instead.

Diagram showing beam deflection limited to a fraction of the spanδDeflection is limited to a fraction of the span (e.g. L/300)A member can be strong enough yet still fail the deflection (sag) check

Understanding Deflection in Span Tables

Span tables limit deflection, not just collapse. Learn why a 'strong enough' member can still sag or bounce, what limits like L/300 mean, and why stiffness drives many MGP10 spans.

Comparison of single span and continuous span membersSingle spanContinuous spanA member crossing three or more supports (continuous) can often span furtherthan the same member in a single span — the tables list them separately

Single vs Continuous Span

Span tables list single and continuous spans separately, and choosing the wrong column is a classic error. Learn the difference, why continuous members span further, and the catch.

A stylised map of Australian wind classification regionsN1–N2N3N4 / CWind classification (N1–N4, C1–C4) changes which span column you read

Wind Classification and Load Width in MGP10 Span Tables

Wind classification (N1–N4, C1–C4) and load width (FLW/RLW) are two inputs that quietly control your span. Learn what they are, how they're determined, and why they matter.

A specification checklist clipboard with ticked itemsConfirm every parameter before you cut — then have it checked

10 Common MGP10 Span Table Mistakes (and How to Avoid Them)

From reading the wrong grade to ignoring wind class and skipping the engineer, here are the most common MGP10 span table mistakes — and how to avoid building in a problem.