The short version: use untreated MGP10 pine for internal framing and general work that stays dry, and use treated pine where the frame will live outdoors above ground and needs protection from termites, rot and decay. Sydney Timber Supply stocks both, sold in set board lengths so you order exactly the sticks you need. This guide covers what MGP10 means, what H3 treatment actually does, where treated pine's limits are, and how STS sizes and lengths work.
What MGP10 means
All STS structural pine is MGP10: machine-graded structural pine. Machine grading means each piece has been graded for structural performance rather than assessed by eye, and MGP10 is the resulting stress grade. When your plans or your builder call for MGP10 framing, this is the product that answers it. Grade and treatment are separate questions: MGP10 tells you about structural performance, while treatment tells you about protection from biological attack. You need to get both right for the job at hand.
When untreated pine is fine
Untreated MGP10 is the standard choice for internal framing and general work: wall frames and similar applications inside the building envelope, where the timber stays dry in service. Inside a closed, dry structure, untreated pine does its structural job without needing preservative protection, and it is the more economical way to frame. STS stocks untreated MGP10 in 90 x 35 mm and 90 x 45 mm; see the untreated pine collection for current lengths and pricing.
What H3 treatment protects against
According to manufacturer technical guidance, H3 treatment protects timber against termites, rot and decay for above-ground outdoor use, and LOSP is a common H3 treatment type. That makes H3 treated pine the framing choice once the timber moves outside the dry interior of a building: outdoor structures and exposed above-ground framing where weather and insects come into play.
The same guidance is clear about the limit: H3 is not rated for in-ground contact. It is an above-ground treatment level. If your design puts timber into the ground, H3 treated framing pine is not the answer, and you should specify accordingly.
At STS, the treatment level of treated pine is confirmed on your quote and delivery paperwork, and our 140 x 45 mm treated pine is evidenced H3. If you need the treatment level documented for a job, that paperwork is where it lives.
STS pine products at a glance
| Product | Size | Treatment | Typical use |
|---|---|---|---|
| Untreated MGP10 pine | 90 x 35 mm | None (untreated) | Internal framing, general work |
| Untreated MGP10 pine | 90 x 45 mm | None (untreated) | Internal framing, general work |
| Treated MGP10 pine | 90 x 45 mm | Treated (level confirmed on quote and delivery paperwork) | Outdoor above-ground framing |
| Treated MGP10 pine | 140 x 45 mm | Treated, evidenced H3 | Outdoor above-ground framing |
Browse the treated pine and untreated pine collections, or start from the shop timber page to see the full range.
How STS sells pine: set lengths
Unlike our hardwood decking, which is sold per linear metre in random lengths, pine framing is sold in set board lengths. On each product page the variant you pick is the length, and the price is that length multiplied by the LM rate. That makes take-off simple: work out your cutting list, pick the lengths that suit it with the least waste, and order the exact count of each length. If your job needs pack or bulk quantities, go quote-first through bulk and pallet orders, and regular buyers can set up a trade account.
Storing pine before installation
A few general good-practice habits protect your framing timber between delivery and installation:
- Store it flat, well supported, so boards stay straight.
- Keep it dry before installation; do not leave packs exposed to the weather.
- Let it acclimatise on site before you fix it.
These apply to treated and untreated pine alike. Treatment protects against termites, rot and decay in service; it is not a reason to store timber badly.
FAQ
Can I use H3 treated pine in the ground?
No. Manufacturer technical guidance states H3 is not rated for in-ground contact. H3 covers above-ground outdoor use only.
Can I use untreated pine outdoors?
Untreated MGP10 is intended for internal framing and general dry work. For outdoor above-ground framing, use treated pine, which is protected against termites, rot and decay per manufacturer technical guidance.
How do I know what treatment my order has?
The treatment level is confirmed on your quote and delivery paperwork. Our 140 x 45 mm treated pine is evidenced H3.
Is MGP10 a treatment level?
No. MGP10 is a machine-graded structural grade. Treatment (such as H3) is a separate property, which is why STS lists treated and untreated MGP10 side by side.
Talk to us
Not sure which pine your job calls for? Send your framing list through the request a quote page and we will confirm sizes, lengths and treatment. Pickup is available from West Gosford, and we deliver to Sydney Metro, the Central Coast, Newcastle and the Hunter, and Wollongong and the Illawarra; see delivery and pickup for details.
Sydney Timber Supply team
Technical details drawn from supplier specification sheets; reviewed 19 July 2026.