Short answer: Dutch timber sizes are given as thickness × width in millimetres, with the length separately in metres. A "5×15 beam" is roughly 50 × 150 mm. Houthandel Jan Sok in Meppel stocks beams from 38 × 89 to 80 × 200 mm, battens from 10 × 40 mm and posts up to 200 × 200 mm, in Douglas fir, spruce, pressure-treated pine, Okan and oak. All prices below: prices as of 5 October 2026, incl. VAT.
How to read timber sizes
- Thickness × width in mm, then the length in metres. Example: 45 × 95 mm, 3.00 m.
- Rough sawn timber keeps the sawn size and a coarse surface. Good for structures, fences and anything you stain later.
- Planed timber is smooth and a few millimetres smaller than the rough size. That is why you see sizes like 44 × 68 or 45 × 70 mm instead of 50 × 70 mm.
- Inch sizes are still used on site: 1 inch is about 25 mm. A "2 by 4" is about 50 × 100 mm, a "2 by 6" about 50 × 150 mm.
- SLS and CLS are Scandinavian and Canadian standard sizes in planed spruce with rounded edges, such as 38 × 89, 38 × 120 and 38 × 140 mm, used for internal walls, floors and battens.
Beams in stock
| Timber | Size and length | Price from |
|---|---|---|
| Douglas fir, rough sawn | 45 × 75 mm, 2.50 m | €6.65 |
| Douglas fir, rough sawn | 50 × 100 mm, 3.00 m | €11.10 |
| Douglas fir, rough sawn | 50 × 150 mm, 3.00 m | €15.90 |
| Douglas fir, rough sawn | 63 × 175 mm, 3.00 m | €24.15 |
| Douglas fir, rough sawn | 70 × 200 mm, 4.00 m | €41.00 |
| Douglas fir, planed | 45 × 70 mm, 2.50 m | €8.40 |
| Douglas fir, planed | 45 × 95 mm, 3.00 m | €13.05 |
| Douglas fir, planed | 45 × 120 mm, 3.00 m | €16.65 |
| Douglas fir, planed | 45 × 160 mm, 4.00 m | €29.60 |
| Spruce, planed | 38 × 89 mm, 3.00 m | €8.25 |
| Spruce, planed | 38 × 120 mm, 3.00 m | €11.25 |
| Spruce, planed | 38 × 140 mm, 3.00 m | €13.05 |
| Spruce, planed | 44 × 68 mm, 3.00 m | €7.95 |
| Spruce, planed, C24 | 58 × 156 mm, 3.00 m | €23.70 |
| Spruce, planed | 70 × 200 mm, 3.00 m | €35.70 |
| Pressure-treated pine, rough sawn | 50 × 150 mm, 3.00 m | €15.85 |
| Pressure-treated pine, planed | 44 × 95 mm, 3.00 m | €9.15 |
| Pressure-treated pine, planed | 45 × 145 mm, 3.00 m | €19.20 |
| Okan hardwood | 50 × 100 mm, 2.50 m | €20.90 |
| Okan hardwood | 50 × 150 mm, 3.00 m | €38.55 |
| Okan hardwood | 80 × 200 mm, 3.00 m | €82.80 |
| Oak, rough sawn | 70 × 150 mm, 3.00 m | €63.60 |
| Oak, rough sawn | 70 × 200 mm, 3.00 m | €88.85 |
The strength class (such as C24) is shown on the product where it is known. For load-bearing structures such as an extension, an upper floor or a large span, have a structural engineer do the calculation.
Battens
| Timber | Size and length | Price from |
|---|---|---|
| Spruce counter batten | 10 × 40 mm, 5.10 m | €2.80 |
| Spruce roofing batten | 20 × 50 mm, 3.00 m | €2.40 |
| Pressure-treated roofing batten | 20 × 45 mm, 3.00 m | €3.00 |
| Douglas fir roofing batten | 22 × 45 mm, 3.00 m | €3.90 |
| Pressure-treated pine, planed | 28 × 80 mm, 3.00 m | €5.85 |
| Pressure-treated pine, planed | 44 × 68 mm, 2.40 m | €5.30 |
| Pressure-treated pine, planed | 45 × 45 mm, 3.00 m | €4.50 |
| Douglas fir, planed | 45 × 45 mm, 3.00 m | €9.45 |
Battens are used behind cladding, as roofing battens or as a frame for sheet material. See also battens behind cladding.
Posts
| Timber | Size and length | Price from |
|---|---|---|
| Pressure-treated pine, planed | 68 × 68 mm, 1.80 m | €4.92 |
| Pressure-treated pine, planed | 88 × 88 mm, 2.40 m | €13.60 |
| Pressure-treated pine, planed | 120 × 120 mm, 3.00 m | €31.65 |
| Douglas fir, rough sawn | 100 × 100 mm, 3.00 m | €22.05 |
| Douglas fir, rough sawn | 120 × 120 mm, 2.50 m | €26.25 |
| Douglas fir, rough sawn | 150 × 150 mm, 2.50 m | €40.15 |
| Douglas fir, rough sawn | 200 × 200 mm, 3.00 m | €88.65 |
| Okan hardwood | 70 × 70 mm, 1.00 m | €7.20 |
| Okan hardwood | 100 × 100 mm, 3.00 m | €51.75 |
| Oak, rough sawn | 150 × 150 mm, 2.50 m | €113.60 |
Douglas fir is durability class 3 and does not belong permanently in the ground. Put Douglas fir posts on a concrete post base or choose hardwood or pressure-treated timber for ground contact. More: which timber can go in the ground?
Which size for which job?
| Use | Common size | Note |
|---|---|---|
| Battens behind cladding | 22 × 45 or 28 × 80 mm | At least 20 mm ventilation gap |
| Fence post | 68 × 68 to 100 × 100 mm | Above 1.80 m: 88 × 88 or heavier |
| Canopy or pergola post | 120 × 120 or 150 × 150 mm | On a concrete base for Douglas fir |
| Purlin up to 3 m span | 50 × 150 mm | Rule of thumb, not a calculation |
| Purlin 3 to 4 m span | 63 × 175 or 70 × 200 mm | Rule of thumb, not a calculation |
| Shed or summer house frame | 45 × 95 or 45 × 120 mm | Studs and rails |
| Internal wall | 38 × 89 mm (SLS) | Planed spruce |
Lengths and cutting to size
Most beams and battens come in 2.50, 3.00 or 4.00 m. If you need other lengths, we cut the timber to size in Meppel. That saves sawing and waste on site. See timber cut to size, or work out quantities first with the calculation tips.
Not sure about a size? Call +31 522 851 551 or send a sketch via the quote page.
Frequently asked questions
How do you read timber sizes?
In the Netherlands timber is sized as thickness × width in millimetres, with the length given separately in metres. A 50 × 150 mm beam of 3.00 m is 50 mm thick, 150 mm wide and 3 metres long. Planed timber is a few millimetres smaller than rough sawn timber of the same nominal size.
What is a 5×15 beam?
A "5×15" beam is roughly 50 × 150 mm. At Houthandel Jan Sok that is, for example, a rough sawn Douglas fir beam 50 × 150 mm of 3.00 m from €15.90, or a pressure-treated pine beam 50 × 150 mm from €15.85 (prices as of 5 October 2026).
What are SLS and CLS sizes?
SLS (Scandinavian Lumber Standard) and CLS (Canadian Lumber Standard) are planed spruce sizes with slightly rounded edges, used for internal walls, floors and battens. Typical sizes are 38 × 89, 38 × 120 and 38 × 140 mm; Jan Sok stocks these as planed spruce.
Which beam do I need for a 4 metre canopy?
As a rule of thumb for a Douglas fir purlin spanning 3 to 4 metres we use 63 × 175 or 70 × 200 mm. This is not a structural calculation: with snow load, a heavy roof or an attachment to the house, have a structural engineer check it.
Do you cut beams to length?
Yes. Houthandel Jan Sok cuts beams, battens, posts and sheet material to size from stock in Meppel. Send a list of sizes; a cutting list with a price indication is usually ready within 1 to 2 working days.