ᐅ Sealing windows airtight

We are currently sealing our windows with butyl tape as instructed by the window installer. According to him, we only need to apply the seal on the sides because we have roller shutter cassette boxes. The boxes are flush with the ceiling-level lintels and have been filled with expanding foam. In his opinion, the plaster ensures the seal at the top.

Does anyone have experience with this topic? I prefer to be on the safe side and wonder whether we should also seal the bottom of the window with butyl tape.

We need to build as airtight as possible since we are installing a ventilation system.

Thank you!
Best regards,
NundE

That should be sufficient. The foam also seals airtight if it’s the right type. You could have used compression tape as well—a self-expanding sealing tape.

PS: Airtightness can also be tricky. 🙂 In the small rooms we have, you need to close the door slowly. Otherwise, overpressure builds up and the door won’t close properly.

Too bad I only found this post today ... :o
... but I think it's great that you relieved the window installers of the (certainly not easy) responsibility for the long-term airtightness of the building component connections!

This must have more than halved their related warranty risk ... 😀.

How did things proceed? Were or are there any moisture issues at the connections?

JOERG24 schrieb:

The foam also provides an airtight seal if it is the right type.

Which foam would you recommend for that purpose?

Hello,

nonsense, there is no foam that is airtight. If a representative tries to convince you otherwise, ask to see the test certificate. To my knowledge, there is no German certified institute that approves such a thing.

The thread starter's question is 5 months old!

There is no point in discussing it now, as it has probably already been resolved (otherwise, they would have followed up by now).