Planed fir post
Planed solid fir post / batten, untreated — sections 7x7cm, 9x9cm, 11x11cm and 14x14cm. Lengths 200cm and 240cm. Class 2. Framing, bioclimatic pergola, partition. Interior and protected exterior. Sold individually.
Planed Fir Post – Sections 7x7cm to 14x14cm, Lengths 200cm and 240cm
This planed solid fir post is a square-section piece intended for load-bearing structures: pergola, carport, garden shed, fence, raised deck. Available in 4 sections — 7x7cm, 9x9cm, 11x11cm, 14x14cm — and in two lengths: 200cm and 240cm. The piece is delivered untreated, ready to be protected according to its use and exposure.
These planed fir posts cover a range from small sections (7x7cm) suited to framing battens and lightweight uprights, up to larger sections (14x14cm) for interior pergolas or covered structures. Planed fir offers sharp edges and smooth faces, suited to applications where the piece is visible.
Main characteristics
| Characteristic | Value |
|---|---|
| Species | Solid fir |
| Finish | Planed — untreated |
| Available sections | 7x7cm, 9x9cm, 11x11cm, 14x14cm |
| Available lengths | 200cm and 240cm |
| Use class | Class 2 — dry interior, covered exterior with appropriate treatment |
| Treatment | Untreated — to be protected according to exposure |
| Drying | Air drying — natural method |
| Conversion | Sold individually |
Key points
- ✓ 4 sections available — 7x7cm, 9x9cm, 11x11cm, 14x14cm
- ✓ 2 lengths — 200cm and 240cm, on-site cutting possible
- ✓ Planed solid fir — class 2 — dry interior, covered exterior with appropriate treatment
- ✓ Air dried — natural method preserving the wood's characteristics
- ✓ Untreated — to be protected according to use and exposure
- ✓ Sold individually
Which section to choose?
The choice of section depends on the post height, the load to be supported and the spacing between posts:
- ✓ 7x7cm — small lightweight structures, single-pitch carports, fences
- ✓ 9x9cm — standard pergola, garden shed, deck up to 3m span
- ✓ 11x11cm — heavy timber framing, gantries, major load-bearing structures
For structures subject to significant loads (snow, wind, spans> 4m), consult a structural timber engineer or carpenter for precise sizing.
Installation advice
Never bury an untreated post directly — even class 3 Douglas fir degrades rapidly in contact with damp ground. For buried posts, use stainless steel fixing plates anchored in concrete, or opt for class 4 (pressure-treated) timber. For posts set on a slab, use adjustable galvanised steel or stainless steel post bases. Apply protection to all faces before installation, paying particular attention to cut ends.
Maintenance and protection
In a dry interior, no treatment required. For a covered pergola or protected outdoor use, apply a fungicidal-insecticidal treatment before installation. Untreated fir is sensitive to moisture — do not expose to the elements without protection.
WoodUp tip
The smaller sections 7x7 and 9x9cm are suitable for interior framing battens and lightweight uprights. For an outdoor bioclimatic pergola, prefer 11x11 or 14x14cm sections and treat the wood before installation.
Important before purchasing: Planed fir has dimensions slightly below the nominal sizes (e.g. 70mm planed for a nominal 7cm section). Check the exact dimensions upon receipt for your assembly calculations.
Frequently asked questions
What section of post for a pergola?
For a standard residential pergola (3–4m span, lightweight roof), the 9x9cm section is generally sufficient for a height of 240cm. For a pergola with a green or heavy roof, or spans> 4m, choose a larger section. If in doubt, consult a carpenter or structural engineer.
Can this post be buried directly in the ground?
No. An untreated post must not be placed in direct contact with damp ground — even class 3 Douglas fir degrades in ground contact (class 4 required). Use a fixing plate anchored in concrete, or order class 4 pressure-treated timber for buried posts.
Does this post need to be treated before use?
Untreated fir is sensitive to moisture — a fungicidal-insecticidal treatment is recommended for any outdoor use. In dry interiors, no treatment is required.
What is the difference between a rough-sawn post and a planed post?
The rough-sawn post retains the natural sawn appearance with slightly irregular faces and nominal dimensions (e.g. 100x100mm). The planed post is machined on all 4 faces for smooth surfaces and precise dimensions, slightly below nominal. For exposed structures, planed offers a neater finish. For concealed or embedded structures, rough-sawn is equivalent.
Can these posts be painted or stained?
Yes. Lightly sand the faces (grit 80–120) before application. For exterior paint, apply a primer specially formulated for resinous wood. For stain or oil, apply directly to dry wood. Planed posts offer better adhesion for finishing products.
Complementary products
Rough-sawn fir post — same species, natural sawn appearance
Planed Douglas post — outdoor alternative
No customer questions for the moment.
Dispatch within 10 days when the product is in stock *.
* Except bespoke products
Dispatched within 6-8 weeks for personalised and made-to-measure products.
Payment in 1 or 3 instalments at no extra cost. Bank transfer, cheque or PayPal
Satisfied or refunded if returned within 14 calendar days (Sundays and public holidays included) following delivery.
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