What Is MGP10? Machine Graded Pine Explained

Updated 2026-01-10 · MGP10 Span Tables

If you have spent any time around Australian timber framing, you have seen "MGP10" stamped along the face of a length of pine. It is one of the most common structural grades in the country — but what does it actually mean, and how does it relate to all those span tables? Here is the plain-English version.

What MGP10 actually means

MGP stands for Machine Graded Pine. The 10 is the stress grade. Rather than a person eyeing each board, machine grading runs the timber through equipment that measures its stiffness and predicts its structural properties, then stamps it accordingly. The MGP family runs MGP10, MGP12 and MGP15, in increasing order of strength and stiffness.

MGP10 is the most widely used of the three — the everyday workhorse grade for house framing. Because each grade has different characteristic properties, each grade has its own span tables. That is the single most important thing to understand before you start looking anything up.

Seasoned softwood

MGP10 is a seasoned (kiln-dried) softwood, typically radiata pine. "Seasoned" means it has been dried to a reference moisture content, so it is dimensionally stable and behaves predictably in service. Building in timber that is much wetter than the reference can lead to shrinkage and movement — one reason a moisture check is worthwhile.

MGP10 vs MGP12, MGP15 and F-grades

• MGP10 / MGP12 / MGP15: the same machine-graded pine system, getting stiffer and stronger as the number rises. Step up to MGP12 or MGP15 when a member needs to span further or carry more in the same size.
• F-grades (F5, F7, F8…): a separate stress-grading system that can apply to various species. AS 1684 publishes span tables for both systems. They are not interchangeable — an F7 table is not an MGP10 table.

Where MGP10 is used

In residential timber-framed construction, MGP10 commonly appears as:

• Wall studs and plates
• Floor joists and bearers
• Roof rafters, ceiling joists and some roof beams
• Lintels over modest openings

For bigger openings, heavy point loads or long spans, MGP10 may not be enough and an engineered product (such as LVL or glulam) or a specific engineering design is used instead.

A note on treatment

MGP10 is a grade, not a treatment. For exposure to weather or ground contact, the timber must be preservative-treated to the right hazard level — for example H2 for internal framing in some regions, H3 for outdoor above-ground (like a deck frame). Grade and treatment are two separate decisions you make for every member.

Where to go next

Now that you know what the grade means, the next step is learning to read the tables correctly. Start with how to read MGP10 span tables, then use the Span Spec Builder to assemble the exact parameters for your lookup. To kit out for the work itself, see our framing tools & reference picks.

Frequently asked questions

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