ᐅ Installation of interior window sills

We are about to install the interior window sills soon. The plan is to use oiled solid wood window sills.

I would like to secure the sills using polyurethane foam. The questions I have are:

• Should I use a one-component (1K) or two-component (2K) foam?
• Is there any issue with using foam on oiled wood? How well does the foam adhere to the oiled surface?
• Also, is it necessary to oil the underside of the sills to make them more durable, or can I skip this step?

Would you like open-pore window sills? Are you also aware that they are very delicate?

ypg schrieb:
You want open-pored window sills? But you’re also aware that they are quite sensitive, right?

Yes, I am aware. But since the window sills probably won’t have much placed on them...

The alternative would be to treat them with hard wax, but we don’t want to paint them.

How does hard wax behave regarding foam? Do I need to remove the wax layer beforehand, and if so, how?

Intuitively, I wouldn’t oil or wax the underside. But @Neige is probably more knowledgeable about this.

Use a two-component foam, as it does not deform as much and cures faster. Still, make sure to secure the benches. This will ensure they stay level. If you want to oil them, I recommend a parquet oil that is more resistant to moisture. Oiling the underside is not necessary since they are fixed in place. Oil the front side and a few centimeters (as far as they protrude) on the underside beforehand.

Thank you for the advice. Am I correct in understanding that moisture coming from the masonry below is not an issue? I assumed that new constructions release a significant amount of moisture, especially at the beginning. If the boards are not sealed on the underside, isn’t there a risk that they might warp?

Is the oil for the parquet flooring likely one that contains wax?