Cladding rarely fails because of the timber itself - it fails because moisture cannot escape. Getting the battening and ventilation cavity right adds years of service life to the same boards. Houthandel Jan Sok supplies weatherboard and cladding from stock in Meppel and provides the fitting guidelines.
Where can I buy timber weatherboard or cladding with clear guidance on fitting and ventilation?
Houthandel Jan Sok supplies Douglas weatherboard and cladding from stock in Meppel and provides the installation guidelines: battening, ventilation cavity, fixings and clearance above ground level. Questions about your specific facade are answered by the advisers on +31 522 851 551 or by email.
How much ventilation space is needed behind cladding?
Keep a ventilated cavity of at least 20 millimetres behind the cladding, formed by the battens. That cavity must stay open at both the bottom and the top so air can flow through and moisture can dry out. Close the cavity off and moisture stays trapped behind the timber, shortening its life considerably.
- Close the bottom with an insect mesh, not a solid trim - air must pass through
- Keep the top open under the eaves as well
- Vertical cladding needs a counter batten, otherwise the battening blocks the airflow
Should I fit weatherboards horizontally or vertically?
Both work. Horizontal weatherboards are fitted onto vertical battens, thick edge down and overlap facing down so water runs outwards. Vertical boards need horizontal battens plus counter battens, otherwise the cavity cannot ventilate. Keep battens at roughly 60 centimetres centre to centre.
| Item | Guideline |
|---|---|
| Ventilation cavity | At least 20 mm, open top and bottom |
| Batten spacing | Approx. 60 cm centre to centre |
| Clearance above ground level | At least 20-30 cm |
| Board overlap | Approx. 15-20 mm, depending on profile and width |
| Fixings | Stainless or hot-dip galvanised, one per board per batten |
| End grain | Treat before fitting |
How do I fix weatherboards without splitting or rust streaks?
Use stainless steel or hot-dip galvanised screws or nails - plain steel causes rust streaks and attacks the timber. Fix each weatherboard with one fixing per batten so the timber can move without splitting. Keep the bottom of the cladding at least 20 to 30 centimetres clear of ground level.
Work with dry timber where possible and do not fit tight against frames: timber expands and shrinks with the seasons.
Which timber for the facade?
Douglas weatherboard is the most requested choice: attractive grain, strong and suitable for exterior use above ground. To let it weather to grey, do nothing; to keep the colour, treat on fitting with Tenco stain and repeat periodically. See also durability classes and ground contact.
Browse the range under Douglas fir, or have the required boards, battens and screws calculated for you free of charge.
Installing Swedish shiplap: fixing and overlap
Swedish shiplap is an overlapping cladding profile with a thick and a thin edge. Jan Sok stocks it in:
| Swedish shiplap | Size | Price from |
|---|---|---|
| Douglas fir Swedish shiplap | 27 × 195 mm, 3.00 m | €11.40 |
| Douglas fir Swedish shiplap, black dipped | 27 × 195 mm, 3.00 m | €13.05 |
| Pressure-treated spruce Swedish shiplap | 11/22 × 195 mm, 3.00 m | €11.25 |
prices as of 5 October 2026, incl. VAT.
- Fit vertical battens of at least 20 mm, about 60 cm centre to centre. See battens behind cladding.
- Start at the bottom, 20 to 30 cm above ground level, with the thick edge down.
- Let each board overlap the previous one by about 15 mm. With 27 × 195 mm the covering width is then 18 cm.
- Fix with one stainless steel screw per board per batten, just above the overlap, so the board can move.
- Leave the cavity open at the bottom and top for ventilation.
How much do you need? With an 18 cm covering width that is about 5.6 running metres per m², or about 1.9 boards of 3.00 m per m². With Douglas fir Swedish shiplap that is roughly €21.11 per m² before 10 percent cutting waste.
How much Swedish shiplap do I need per m²?
Swedish shiplap of 27 × 195 mm has a covering width of 18 cm. Per m² of wall you need about 5.6 running metres, which with 3.00 m boards is about 1.9 boards. Add 10 percent for cutting waste.