Seal around Windows?

Deco99 · 24-01-2021 1:57am #1

Hi, new windows installed. House replastered. I don't see any noticeable gaps between the plaster and window frame. Just wondering, aside from caulking the window board, do I still apply sealant to the rest of the windows/doors

WildCardDoW · 24-01-2021 2:00am

Deco99 wrote: »

Hi, new windows installed. House replastered. I don't see any noticeable gaps between the plaster and window frame. Just wondering, aside from caulking the window board, do I still apply sealant to the rest of the windows/doors

No, hopefully the plasterer (or someone) sealed the windows if they weren't already. You'd seal from the window to the concrete and put the plasterboard or plaster over this. That's usually how you get an airtight seal at windows!

Deco99 · 24-01-2021 10:53am

WildCardDoW wrote: »

No, hopefully the plasterer (or someone) sealed the windows if they weren't already. You'd seal from the window to the concrete and put the plasterboard or plaster over this. That's usually how you get an airtight seal at windows!

Ah right. Ya, there was expanding foam put around them when being installed.

Evd-Burner · 24-01-2021 11:34am

I bought a house over a year ago and noticed bad drafts at the front of the house where there is a cavity wall. I was going to replace the windows and also have the cavity pumped. Insulation guy said pvc windows were good this his work would seal them, recommending just a service.

He insulated the cavity between the bricks/blocks and between plasterboard and inner leaf. A huge amount of insulation was coming out around the external windows. I don't think there was any sealing at all, all of huge came out after the guy made a large effort to block up holes and cracks etc.

There is virtually no drafts now!

listermint · 24-01-2021 11:37am

Expanding foam doesn't provide an airtight seal. It never will it's a middling replacement for airtight tape.

If anyone's getting windows installed they should prepurchase airtight tape and when windows are done put the tape on something like contega SL which can be plastered to easily.

Foam and caulk are a poor replacement for above. But are better than none .

jaykayphd · 04-10-2022 9:18am

Hi,

We hope to replace the windows in our 1980's Semi-D. The couple of windows installers we have spoken to to-date don't/won't install airtight tape. One made a point that in such a house there are probably many other air leaks and that foaming would be fine. We are also having EWI installed. I assume as the window reveal brickwork will be accessible I should ensure that tape is used? Brickwork is un-plastered cavity-block. Plasterboard is dot-and-dabbed to this. Thanks

10-10-20 · 04-10-2022 5:58pm

https://www.boards.ie/discussion/comment/119698639#Comment_119698639

Given that you're installing EWI, I'd probably be 50/50 in agreement with the installer here. If it was just windows alone and no EWI I'd have to fully agree with him. For completeness-sake, I'd prefer to have them taped. In a lot of these retrofits they don't always do a good job of sealing in the windows as the gaps are too narrow for the foam, leaving cavities. The tape would take care of a lot of this.

Let's see what others think.

monseiur · 05-10-2022 10:05am

Can I butt in and ask a quick question as I will be replacing windows next year- Where exactly does the tape go, is it on the inside where the window frame meets the internal wall of cavity ?

10-10-20 · 05-10-2022 10:12am

https://www.boards.ie/discussion/comment/119703336#Comment_119703336

Yes, see images here for example:

https://www.prodomo.ie/2019/04/05/best-practice-for-taping-around-windows/

GreeBo · 05-10-2022 4:25pm

https://www.boards.ie/discussion/comment/119701066#Comment_119701066

I think if I was just doing the windows I'd want them taped as maybe I'd address the other issues at some point in the future and it would be painful to try and fix the windows then.

If taping is the right thing to do, then its always the right thing to do imo!

10-10-20 · 05-10-2022 4:55pm

https://www.boards.ie/discussion/comment/119705235#Comment_119705235

There's a balanced and fair opinion.

But the taping of said windows isn't the window-installers job, OP.

jaykayphd · 05-10-2022 5:38pm

Thanks for the replies. I have two options with the installation. The window installers have quoted for replastering the reveals and new window boards. I could either install the tape myself with YouTube help prior to them making good, or contract someone else to tape and make good the reveals. But will defo go for taping.

MicktheMan · 10-10-2022 9:18pm

https://www.boards.ie/discussion/comment/119698639#Comment_119698639

In addition to taping the windows internally ...

The best approach when replacing windows AND installing EWI is to move the new windows out to be flush with the original walls to allow the new ewi overlap the window frames reducing significantly the thermal bridging. Not done regularly but much better result.

jaykayphd · 13-10-2022 10:39am

https://www.boards.ie/discussion/comment/119727951#Comment_119727951

Thanks Mick

Yeah I have requested this from the window installers and all have no problem doing this. None knew what I was talking about when I referred to hanging the windows on the external leaf to be fully within the EWI as mentioned on this site.

Seal around Windows?

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