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:
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?
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Sackkarre20 Oct 2016 21:30garfunkel schrieb:
I installed my window sills using wooden shims for height adjustment and plenty of silicone because I found foam too risky due to the building conditions.
Later, I learned that door frame foam doesn’t expand or push out as much. Can anyone confirm this? If that’s true, it could be a good option for future projects. For height leveling and load-bearing stability, I also used shims and foamed them in place directly, spaced about 30-50cm (12-20 inches) apart. I placed one row on the window side and another roughly one third of the way in toward the room side. I used plastic wedges that can interlock to adjust the height.
In my opinion, the two-component (2K) foam was the perfect choice. As Neige mentioned, it cures very quickly, allowing for fast continuation of work. It also expands much less than the one-component (1K) foam, ensuring good filling of the cavity without lifting the window sills too much. For this task, I would always prefer 2K foam over 1K foam.