ᐅ Exterior window sill / compressible sealing tape

Hello,
before the warranty period ends, I would like to clarify a few points.

The first point concerns the plastering of the exterior window sills.
After some plaster chipped off at the end of a window sill, I noticed that a thin metal spring strip can be inserted quite far in that spot, see photos.
This seems to contradict what I believe I once read.

Isn't it the case that before plastering, a compression tape (Kompriband) must be applied over the end of the window sill, running above and down the sides?

Hello,

I would really appreciate it if someone could take the time to give even a very brief reply.

Happy holidays!

alive&kicking schrieb:

Isn't it the case that before plastering, a compressible sealing tape must be applied above and down the sides over the end part of the window sill?

Yes, that is the usual practice.
Do you have any photos from the construction phase?

Thank you, nordanney,

sorry for the late reply, Christmas and all that!

Unfortunately, I don’t have any photos of this, as I wasn’t on the construction site at that time.
So the matter with the compressible sealing tape is clear.

Is a second sealing layer required below this type of window sill, and does the cavity beneath it need to be foam-filled without exception?

Thanks and best regards

In timber frame construction, these are always present. Solid construction (or with ETICS) is only necessary if a wind-driven rain-tight installation cannot be ensured. With ETICS and slip sheets, as well as backer rods and proper installation (for example, no service penetrations in the corner or professionally sealed), you don’t need them.

Whether foam insulation is used also depends on the installation situation. For ETICS, there are sloped base insulation options that eliminate the need for foam completely. However, this really depends on the specific installation conditions.

In my DIY project, I used foam insulation under the bench and also to bond the bench in place.

Thank you for the incredibly quick information!

We used solid construction. I still need to check the trade hole; we definitely don’t have wedges, so I need to see what’s underneath.

Thank you very much for your helpful answers, nordanney!