In a pine size such as 90 x 45, the first number is the width and the second is the thickness, both in millimetres. H3 means the timber is treated for use outdoors, above ground, where it gets wet from time to time. H3 is not for in-ground contact. We list H3 treated pine framing in 70 x 35, 70 x 45 and 90 x 35, plus treated 90 x 45 and 140 x 45. Which section a structural member needs comes from your plans, the AS 1684 span tables or your engineer. This guide does not give spans or loads.
The sizes we list
| Section (mm) | Grade and treatment | How it is sold |
|---|---|---|
| 70 x 35, dressed all round | MGP10 / F7, H3 | Per linear metre |
| 70 x 45, dressed all round | MGP10 / F7, H3 | Per linear metre |
| 90 x 35, dressed all round | MGP10 / F7, H3 | Per linear metre |
| 90 x 45 | MGP10, treated (level confirmed on quote and delivery paperwork) | By the board, set lengths |
| 140 x 45 | MGP10, H3 | By the board, set lengths |
Grades and treatment are as shown by our supplier. For the three linear-metre sizes, you order the total linear metres and the lengths supplied are confirmed with your order. Their online prices are for loose lengths; full-pack pricing is by quote. Each product page shows current availability. We also list untreated MGP10 pine for dry, internal work; see treated vs untreated pine framing for that choice.
Reading the two numbers
- 70 or 90 is the width. In a wall frame it sets the depth of the frame. A 90 mm stud makes a deeper wall than a 70 mm stud.
- 35 or 45 is the thickness. It changes the face you fix into and how much timber is in the section.
- Sizes are the listed section. The three linear-metre sizes are dressed all round (smooth on four faces). If an exact finished dimension matters to your detail, ask us to confirm it before you order.
WoodSolutions' Lightweight Timber Framing Guide describes residential studs as typically 90 x 35 or 90 x 45 machine-graded pine, and joists in standard raised timber floors as usually 90 x 45 MGP10. It also says member sizes and spacings are governed by AS 1684. Treat those as descriptions of common practice, not as a size for your job.
What H3 covers, and what it does not
Under the AS 1604 hazard classes, as summarised by Business Queensland, H3 is for timber kept off the ground but exposed to weather or periodic wetting, and is designed to reduce the likelihood of attack by insects (including termites) and decay. Higher classes also suit the conditions of the lower ones, so H3 also meets H1 and H2 conditions.
- Not for in-ground contact. Ground contact or continually damp positions call for H4 or above; our guide to H3 vs H4 treated pine covers the difference.
- Close to the ground, check with your designer. WoodSolutions guidance asks for more durable or more highly treated framing in decks close to the ground; see deck subframes.
- Treatment is not the grade. H3 is about protection; MGP10 and F7 are stress grades, explained in MGP10, MGP12 and F7. Your plans specify both.
Check the brand, seal the cuts
- Look for the treatment brand. Business Queensland's summary of AS 1604 says treated wood should carry a brand showing the treatment plant number, the preservative code and the H class. Pieces over 15 mm thick are branded on the piece or with a sticker; some small sections can carry the brand on the bundle or delivery docket.
- Re-seal cut ends. WoodSolutions guidance is that cut ends, drill holes and rebates in treated timber are re-coated on site with a suitable preservative or primer.
- Use compatible fixings. Check that fasteners suit the treatment and the exposure; WoodSolutions lists hot-dip galvanised or stainless steel for copper-based treatments.
Ordering
For 70 x 35, 70 x 45 and 90 x 35, enter the total linear metres you need. For 90 x 45 and 140 x 45 treated, pick the length on the product page and order the number of boards. Our guide to turning a framing cutting list into a pine order works through both. If your job needs packs or a mix of sections and lengths, send the list through request a quote or see bulk and pallet orders. None of our pine framing carries a pack-opening fee.
FAQ
Can H3 treated pine go in the ground?
No. H3 is for above-ground exposure. In-ground use needs a higher hazard class or a durable hardwood, as your designer specifies.
Should I use 70 x 35 or 90 x 45?
Your plans, the AS 1684 span tables or your engineer set the section for each structural member. We supply the section you specify; we do not give span or load advice.
What do MGP10 and F7 mean on the same product?
Both are stress grades. Our supplier lists these three profiles as MGP10 / F7. Check which grade your plans call for.
How do I know the treatment level of my order?
Look for the brand on the timber or its pack, as above. For 90 x 45 treated, the treatment level is confirmed on your quote and delivery paperwork.
Do you sell H2 or H4 pine?
Not as listed products. Sizes and treatments we do not list can be quoted; send the details through request a quote.
Talk to us
Send your framing list, the section and grade from your plans, and your delivery postcode or a request to collect, through request a quote, and we will confirm availability, lengths and price.
Sydney Timber Supply team
Product details from our supplier's price list and specification sheets; treatment and framing references from Business Queensland and WoodSolutions. Reviewed October 2026.