ᐅ Wooden Decking – Which Type of Wood to Choose, or WPC Decking?

Actually, I thought that wood like larch shouldn’t be coated with paint because it doesn’t allow vapor diffusion. This causes the wood to rot much faster. In our area, untreated larch facades are quite common.

All or nothing, explosive. Either you paint all sides and seal the wood completely, or you don’t paint at all. Rotting at the edges is a well-known issue with wooden windows. I would never bother painting a terrace due to the effort involved. On boats, with constant water exposure, it’s a different situation. However, rot remains a persistent problem there as well. That’s why solid wood boats have practically disappeared. You either use plastic or, if wood, then two-component sealed, molded plywood. In commercial construction, it’s basically steel only.

Since we are currently planning the terrace, I’ll join the discussion here.
The terrace will be about 30m² (320 sq ft) in size; an additional one on stilts, approximately 8m² (86 sq ft), will be built next year.
The terrace faces southwest and will be uncovered.

I’m now considering the best type of wood for the surface.

The options are Douglas fir or larch, which have already been recommended here, or thermally modified pine. Has anyone had experience with the latter?

The decking boards will be laid parallel to the house wall with a slope away from the house, so they should be smooth, not grooved, to allow water to drain properly. Additionally, the substructure should prevent direct contact with the ground.

I’m not concerned about wood discoloration; in fact, I find it appealing. My bigger concern is splinters. Sellers of thermally modified pine often claim it is much less prone to splintering than larch. Does anyone have experience with one or both of these wood types? With a smooth surface, I imagine that if splinters form over time, I could simply sand off the top 1–2mm (0.04–0.08 inches), similar to sanding parquet, and then be fine again. Am I mistaken?

dertill schrieb:
Thermo pine

I can only compare my experience with thermo ash to thermo wood. The woods are quite similar after the thermal treatment.
- very dry ==> tend to crack during processing
- very smooth
- no splintering

Only sand if you are fastening from underneath. Otherwise, you will have hundreds of screw heads in the way on top...

Oh, and please pre-drill. The wood will appreciate it and is less likely to split.

nordanney schrieb:
- very smooth

Very smooth in a negative sense? So slippery when wet, more slippery than untreated larch/Douglas fir (without grooving)?

dertill schrieb:
Very smooth in a negative way? So slippery when wet, more slippery than untreated larch/Douglas fir (without grooving)?

In a positive sense. All woods tend to be slippery to some extent, especially if you walk on them with certain types of shoes or heels. It’s no different with grooved surfaces—in fact, those can be more prone to rotting in the grooves where water collects.

Very comfortable to walk on barefoot. My twins played on it from birth until they were 5 years old, and none of them ever complained about splinters.