MGP Grades
MGP10 vs MGP12: What the Grades Actually Mean
If you have ever stood at a rack of framing pine, you have seen MGP10 stamped along the timber, and if you have read a set of plans, you may have met MGP12 too. The two names raise the same questions over and over: what the numbers mean, whether one is better, whether the timber is treated, and what happens if it gets wet. Here are the straight answers, and whichever grade your plans call for, Allmat can quote it.
What does MGP mean?
MGP stands for Machine Graded Pine. Rather than a grader eyeballing each stick, every length runs through a machine that bends it and measures how much it resists, grading the actual timber rather than its appearance. That is why MGP grades are so consistent, and why the same stamp means the same performance whether the stick was milled in Mount Gambier or imported.
The number is the stiffness. MGP10 is graded to a stiffness of around 10,000 MPa, and MGP12 to around 12,700 MPa. MGP12 also carries higher strength values. If you want the back story on where the pine itself comes from, our guide to where Australian structural pine comes from covers it.
So which one does your job need?
For most residential framing, the answer is MGP10. It is the standard grade Australian houses are built from, it is what merchants stock in depth, and it is a good structural grade, not a budget one. Walls, roof framing and general structural work on a standard home are overwhelmingly MGP10 territory.
MGP12 is a specified product. It turns up when a building designer or engineer wants extra stiffness from the same size of timber, often on longer spans or tighter deflection limits, and it says so on the plans. If your plans say MGP12, that is what the job needs. If they say MGP10, there is nothing to gain by second-guessing it.
One rule worth knowing: it is accepted practice that a higher grade can stand in for a lower one in the same size and treatment, because it meets everything the lower grade promises. The reverse is never true. So MGP12 can go where MGP10 was called for, with your designer’s nod on an engineered job, but MGP10 must never go where the plans say MGP12.
And on spans: sizing members is span-table and engineering territory, which belongs with your designer or engineer, not a merchant’s article. What we can tell you quickly is price and availability for whichever grade the plans call for.
Grade and treatment are two different things
A lot of the confusion around MGP10 comes from mixing it up with treatment. The MGP grade describes how strong and stiff the timber is. The H rating describes what the timber is protected against. They are separate axes, and one stick carries both: you can buy untreated MGP10, H2 treated MGP10, or H3 treated MGP10, all the same strength grade.
So a question like "MGP10 vs H3" is really asking about two different things at once. If the timber is staying inside the building envelope, untreated or H2 MGP10 is the usual answer. If it lives outside, protected and above ground, it wants H3. For the full rundown of H ratings and treatment types, see Treated Timber Explained.
The same logic answers the wet-weather worry: framing that cops rain during the build is normal and dries out, but timber that stays exposed needs the right H rating. No MGP grade is waterproof, because grades were never about water.
Where to buy MGP10 in Adelaide
In Adelaide, the answer is Allmat. We stock MGP10 in untreated and H3 across the common framing sizes, along with H4 treated pine posts, and we can get MGP12 and H2 in for specified or bulk jobs. The full size list lives on our MGP10 page.
Framing list ready? Send it through and we will price it, or fold it into a job-lot quote with the rest of your materials. The sizes and treatments we carry are on the MGP10 page.
Allmat: framing pine without the guesswork
The name Allmat comes from All Materials, and framing pine is the bread and butter of it. MGP10 on the rack, MGP12 when the plans call for it, and straight answers on grades and treatments when the stamp on the timber is not making sense. Whether you are a builder, a hardware store or framing your own shed, send us the list and we will quote it.
MGP Grade FAQs
MGP is Machine Graded Pine, and the 10 points to the grade’s stiffness, around 10,000 MPa. Every length is machine tested for stiffness as it is graded, which is what makes MGP grades so consistent: an MGP10 stick performs as MGP10 wherever it was milled.
It is stiffer and stronger, not better. MGP10 is a good structural grade and it frames most Australian houses. MGP12 earns its place where the design needs the extra stiffness, which is a call your building designer or engineer makes, not an upgrade you need to seek out on a standard job.
Generally yes. It is accepted practice that a higher grade can take the place of a lower one in the same size and treatment, since it meets everything the lower grade promises. If the job is engineered, confirm the substitution with your designer. The reverse is the one that matters: never put MGP10 where MGP12 is specified.
MGP10 comes both ways. Untreated MGP10 is the everyday framing stick. The same grade is also sold treated, commonly H2 (termite protection for inside the envelope, the blue framing pine) or H3 (for outside, protected above-ground use). The grade describes strength and the H rating describes treatment: one stick of timber carries both.
The grade has nothing to do with weather. A frame getting rained on during construction is normal and it dries out, but timber that stays exposed needs the right treatment, not a grade: H3 MGP10 for protected outdoor work above the ground. Untreated MGP10 belongs inside the building envelope.
They come from different grading systems. F grades are an older stress-grading system still used for hardwoods and some products, while MGP replaced them for machine-graded pine framing. The two do not convert neatly one-to-one, so if plans mix them, have your designer confirm the right member rather than swapping on a rule of thumb.
From Allmat. We stock MGP10 in untreated and H3 across the common framing sizes, plus H4 treated pine posts, and we can get MGP12 and H2 in for specified or bulk jobs. Send us the framing list and we will quote it.
Get a Framing Quote
Send us your framing list with sizes, grade and treatment, and we will get pricing and availability back to you.