Window interior sealing with sealing tape

Hello everyone,

the windows were installed by the window installer, and after I was somewhat shocked by the quality of the workmanship, I also had an expert sent over who found various defects.

Unfortunately, I only have a negative example from my construction site. So the question is, what does proper sealing tape installation look like? The expert said it should be sealed airtight on the inner reveal. Does that mean the tape runs continuously on each side and lies absolutely flat against the wall?
In my case, it looks more like this:


The good thing is that the window installer apparently understands that this is not acceptable. How to correct this now without removing all the windows again (some of which were installed with a crane) will be something we try to clarify on the construction site tomorrow. Would it be an option to apply another layer of tape overlapping?

I would be grateful for any tips.

Everything has been done correctly. It doesn't look very nice visually now, but functionally it fits.

There are self-adhesive sealing tapes that are also breathable. This tape seems more plastic-like. The adhesive was just applied a bit too thickly on the wall. It doesn't seem to be self-adhesive. However, since this tape will be plastered over, it will disappear under the plaster. If you want to put another overlapping layer on top, the plasterer will probably get upset because the plaster won't hold.

Leave it as it is. Except at the transitions, you could do some touch-up work and cover the gaps with tape. Otherwise, leave it like that and coordinate best with the plasterer. As mentioned, it already seals because it seems to be properly glued to the window profile.

I would say remove all the windows, stick new sealing tape to the frames, and then fully seal with the proper adhesive to the masonry.

Everything has been done correctly. It doesn't look very nice visually now, but in terms of functionality, it's fine. (...)

With all due respect, anyone who calls this correct has never seen professionally installed windows in their life. This is sheer nonsense; the patching with expanding foam alone already shows that this is everything but airtight.

Take a look at a video from Hornbach on YouTube to see how this is done properly. It definitely does NOT look like this afterwards.

So the sealing tape is definitely self-adhesive. What is oozing out is excess mounting foam. The expert also criticized that. I think the segmentation of the tape in the upper area of the windows is due to the fact that the windows were probably installed first and then the mounting boxes, for whatever reason. I am pretty sure that the window installer will not agree to a complete reinstallation (almost) of all windows. What would be an acceptable repair? Remove the sealing tape from the reveal, remove the excess foam and then either fix the tape with adhesive or apply another layer of tape over it?

You have an expert. What are you paying them for if you have to ask for the proper repair in an internet forum? I know it like this: Stick sealing tape onto the frame, there it is self-adhesive. Then a thick bead is applied to the reveal, e.g. adhesive from Illbruck, and the sealing tape is pressed in. If you've ever held a cartridge like that in your hand, you can already see from the nozzle that a really thick layer of adhesive must be applied, which has nothing to do with those 3mm gaps you know from silicone. Masonry is not a 100% even surface, how could self-adhesive tape ever be airtight there? At best, it compensates 0.1mm, if at all. Foam has no place there.