Was the installation of our new building windows carried out professionally?

Hello forum,

Recently, the windows were installed in our new building. The inner sealing tapes were glued onto an existing bitumen membrane instead of the masonry. The bitumen membranes were there to protect the bricks from water. The window installer simply left them as they were and installed the windows. Our site manager says that this is not a big deal.

I fear that the sealing is not ensured because the bitumen membranes lie under the sealing tapes both inside and outside, so there is always a "gap" to the masonry. What do you think?

Attached are some pictures so you know what I mean.

Does sealing tape still need to be glued at all?

Regarding the question, I also find it questionable.

The internal sealing tapes were glued onto an existing bitumen membrane instead of onto the masonry.

Layman's opinion: That is not correct.

Tip: Have them tell you which sealing tape was used. Then ask the manufacturer of the sealing tape for the processing instructions. Of course, you can also simply report the defect to your contractor and demand rectification (in my opinion, that would not be a big deal at the moment). Depending on the response, you must then determine the further course of action.

Recommended reading (internet search engine of your choice): Properly sealing windows - ift Rosenheim (pdf).

It would be easier if linking were allowed here ...

The bitumen membrane does not seem to be glued, consequently it is definitely not sealing against the masonry. Therefore, he could basically have spared the Siga tape in that area! I therefore cannot imagine that this is professionally done. I would at least expect that the bitumen membrane is cut off at the frame and then a new tape is applied (provided the substrate is professionally prepared).

In the current condition, I would have serious doubts about the professional installation!

Would at least expect that the bitumen membrane is cut at the frame and then a new strip is glued

I would say: Take it out again and reinstall properly. At the current stage of construction, that doesn't hurt.

Of course, you can simply report the defect to your contract partner and demand rectification

Exactly. Better to have a rejected complaint than one that is not submitted on time. Although I have little doubt here that it could have been done professionally despite the initial appearance.

I would say: Go out again and reinstall properly. That doesn't hurt at the current stage of construction.

That should be the demand. Unfortunately, the market for window installation subcontractors is currently well supplied with unskilled and casual workers; accurate operators are rare.