Sealing tape for the window frame

As always, here are ignorant half-truths.

There is a standardized RAL installation for windows, and construction foam has no place in it. If my window installer showed up with construction foam, he would be sent home immediately.

And this installation method has not existed for just a few months but for many years. The appropriate compression tapes come in various designs for every conceivable window recess.

The problem, as always, is the cost. Naturally, much higher than with construction foam. But the best windows are useless if they are not installed properly. Because that is what matters.

The compression tape also includes a window connection tape, diffusion-open on the outside, not diffusion-open on the inside. This connection tape is then plastered in.

Construction foam is not excluded, but both the sealing and the soundproofing are like night and day. People buy windows at astronomical prices and then save a few euros on installation costs.

I once commissioned a carpenter to install windows at one of my properties. That was a complete disaster. I then installed my windows myself. That way I don’t have to get annoyed by any bunglers.

By the way, every proper bricklayer plasters the window reveals before window installation. Why not?

By the way, the compression tape (multi-function sealing tape) we used didn't care if the wall opening had a 10 mm gap at the top, 20 mm in the middle, and 15 mm at the bottom. It fills up to 50 mm without any problems.
If it's cold, it just takes longer.

Yes. You did it that way because you don't care that the stuff costs 4 times as much as one that expands to 15 mm.
For the window installer who buys the stuff in large quantities and has to make a living and pay employees, it doesn't matter to him, he saves wherever he can.

And then it's suddenly 17 mm instead of 15. Suddenly, the homeowner has a 2 mm air gap between the interior and exterior plaster.

I have already talked to several experts. They all say:
Compression tape is better than foam, if it is installed 100% correctly. And precisely this 100% correct installation is rarely the case nowadays.

As always, here are ignorant half-truths.

There is a standardized RAL installation for windows and expanding foam has no place there. If my window installer showed up with expanding foam, he would have to go home immediately.

Show me where it says that. RAL only prescribes that you must not work with expanding foam only. If a window connection tape is used on the inside and a rainproof plaster strip on the outside, expanding foam is okay in between, even according to RAL.

Half-knowledge, yeah yeah...

PS: By the way, the "better" but more complicated approach is my experience from 12 years as an electrical engineer in special system construction. The "better" solution is often the worse one because it is much more complex, prone to errors, more expensive... and above all, it must be installed with a level of care that you rarely achieve even in precision mechanical engineering...

I slowly believe that something is wrong with my RAL "Guideline for Planning and... Installation of Windows..." Edition 2020. It does not mention anything about wind braces and that construction foam is prohibited. Besides many other permissible methods, there is also a chapter about multifunctional sealing tapes ("3D compressible tapes") that are watertight on the outside against driving rain and airtight on the inside.

and don't forget, there are probably also significant quality differences with the Kompribänder!

if possible, it should be "imprägnated Kompriband".