A guide to MGP10 vs MGP12 timber
With so many different structural timbers on the market these days, the right selection can get pretty confusing. With over 130 years of timber experience, so we have put together this helpful 'MGP10 vs MGP12 Guide' to make things easier for you.
Our guide will help you choose the right structural pine for Australian home building — along with understanding the main features, benefits, applications and selection criteria.
The main difference is stiffness. MGP10 clears a minimum Modulus of Elasticity of ~10,000 MPa; MGP12 clears ~12,700 MPa — about 27% stiffer, with bending strength jumping from 17 to 28 MPa. Both are the same seasoned plantation pine (i.e. radiata/slash/caribbean), machine-graded under AS/NZS 1748 with design properties from AS 1720.1. The only difference is measured performance, not species or appearance.
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Shop the SALE nowKey features and benefits of MGP10 vs MGP12
Our helpful guide will go through the various features and benefits to make understanding easier.
What is the difference between MGP10 vs MGP12 grades?
Choosing the right structural timber starts with understanding the differences between MGP10 vs MGP12. Machine-Graded Pine (or MGP) is the standard framing material for Australian residential construction, graded to AS 1748.
Machine Graded Pine (MGP) is the workhorse of Australian residential framing. MGP10 and MGP12 look almost identical on the rack, but they behave differently under load.
- MGP10 is the most widely specified grade that is suitable for wall frames, roof trusses, and general-purpose framing.
- MGP12 offers higher stiffness and is specified where greater spanning capacity or load performance is required, such as long-span floor joists or heavily loaded lintels.
Our guide explains in more detail what separates the two grades, where each earns its place in a build, and how to specify with confidence.
Understanding the technical terminology and differences between MGP10 vs MGP12 timber
MGP10 — Features, Benefits & Applications
MGP10 is the most widely used structural pine grade in Australian housing.
It is the cost-effective baseline that most everyday framing is designed around — reliable, readily available in every yard, and comfortably strong enough for standard spans and spacings.
Features
- Minimum stiffness of about 10,000 MPa (MOE) — the entry point of the MGP scale.
- Seasoned plantation pine with a clean, uniform, machine-graded appearance.
- Supplied in the full range of common framing sizes (70, 90, 120, 140, 190 mm depths in 35/45 mm thicknesses).
- Available in preservative treatment levels (e.g. H2 blue for internal framing, H3 for protected external use) — treatment is separate from structural grade.
Benefits
- Economy — the lowest-cost structural grade; ideal where the design does not demand extra stiffness.
- Availability — stocked everywhere, so lead times and substitutions are rarely an issue.
- Design support — AS 1684 span tables and manufacturer literature are built around MGP10, making it quick to size and certify.
- Workability — light, easy to cut, nail and fix by hand on site.
Typical applications
- Wall framing — studs, plates and noggings in load-bearing and non-load-bearing walls.
- Roof framing — rafters, ceiling joists, battens and general roof members at standard spans.
- Floor joists and bearers within span-table limits.
- General light-load framing, subframes and everyday residential carpentry.
MGP12 — Features, Benefits & Applications
MGP12 is the step up.
With roughly 27% more stiffness and markedly higher bending strength than MGP10, it lets a member span further, carry more, or be sized down for the same job. It costs more and is not stocked as deeply, so it is specified where performance genuinely earns its keep.
Features
- Minimum stiffness of about 12,700 MPa (MOE) — noticeably stiffer than MGP10.
- Higher characteristic bending, tension and compression capacities across the board.
- Same species and seasoned pine base as MGP10 — the difference is structural, not visual.
- Available in the same sizes and treatment levels, though stock depth varies by supplier.
Benefits
- Longer spans — greater stiffness means less deflection, so members reach further before hitting
- serviceability limits.
- Higher loads — better suited to concentrated or heavier loads such as floor systems and supporting members.
- Design flexibility — can allow a shallower or thinner section for the same span, freeing up ceiling height or reducing member count.
- Headroom — useful where deflection or bounce needs to be tightly controlled (e.g. stiffer floors).
Typical applications
- Floor joists and bearers on longer spans or heavier floor loads.
- Rafters and roof members where span or load exceeds comfortable MGP10 limits.
- Lintels and supporting members within engineered or span-table provisions.
- Situations where an engineer specifies the higher grade to control deflection or reduce member size.
Key Selection Criteria
Grade is only one of several decisions when specifying structural pine. Work through these together rather than in isolation.
| Criterion | What to look for |
| Structural demand (span & load) | Start here. Check the AS 1684 span tables or the engineer’s design for the member, size, spacing and load. If MGP10 spans it comfortably, there is rarely a reason to pay for MGP12. If it is marginal, MGP12 (or a deeper section) closes the gap. |
| Deflection & serviceability | For floors especially, stiffness governs bounce and feel. Where a springy floor is a risk, MGP12’s higher MOE is often the cleaner fix than upsizing. |
| The specification is binding | If the engineer, span table or certifier calls up a specific grade, match it. You may substitute MGP up for a compatible F-grade, but never substitute down or swap an MGP call-out for F-grade. |
| Durability & treatment (H-class) |
Structural grade and durability are separate. Match the hazard level to the exposure — H2 for protected internal framing, H3 for above-ground external, and higher for damp or ground contact. Untreated pine is unsuitable for exposed or damp locations. |
| Size & availability | MGP10 is stocked deeply in all common sizes; MGP12 stock varies by supplier and region. Confirm availability and lead time before designing around it. |
| Cost & overall economy | MGP12 costs more per length, but if it lets you use fewer or shallower members the total can be competitive. Weigh material cost against labour, member count and headroom. |
| Grade stamp & compliance | Only use timber that is clearly and legibly grade-stamped. The stamp is your evidence of compliance for certification — reject unmarked or illegibly marked structural timber. |
| Moisture & storage on site | Keep seasoned pine dry, stacked and ventilated. Poor storage causes movement, warping and checking that can compromise otherwise sound structural timber. |
Summary Comparison MGP10 vs MGP12 grades
The main points at a glance. Use this as a quick reference, not a substitute for the span tables or the engineer’s design. Always check with our Big River technical team to ensure you select the right structural timber material for your specific home building application.
Bottom line: Use MGP10 as your default for standard residential framing — it is cheaper, everywhere, and strong enough for most walls, roofs and joists. Reach for MGP12 when you need to span further, carry more, control deflection, or size a member down. Above all, when a grade is specified, match or exceed it — never substitute down.
| Aspect | MGP10 | MGP12 |
| Positioning | Residential default / baseline grade | Higher-performance upgrade grade |
| Stiffness (MOE) | ~10,000 Mpa | ~12,700 MPa (+27%) |
| Bending strength (f’b) | 17 Mpa | 28 MPa (+65%) |
| Relative strength | Strong enough for standard framing | Stronger & stiffer across the board |
| Best for | Walls, roof framing, general framing, standard joists | Longer-span joists/bearers, heavier loads, tighter deflection |
| Spans | Standard spans per AS 1684 | Longer spans or shallower sections for same span |
| Cost | Lower — most economical | Higher per length |
| Availability | Stocked everywhere, all common sizes | Varies by supplier / region |
| Nearest F-grade | » F7 | » F8 |
| Substitution rule | MGP may replace compatible F-grade; F-grade must NOT replace an MGP call-out |
As per MGP10 — always match or exceed the specified grade |
A guide to understanding MGP10 vs MGP12 timber
Product range
Structural Pine Framing
MGP10 and MGP12 structural pine for wall frames and roof trusses.
Residential and commercial framing