Airtightness tape for windows and doors

[Adsibob]

Apologies if this has been covered before, but the few recent threads I found linked to products whose links had broken.  What tape do people recommend for ensuring the junction between aluminium windows/sliding doors are airtight. The only tapes I have found are really expensive (over £3 a linear metre) and are much wider than I need, at about 60mm or 75mm wide. I have very narrow framed windows so probably can do with much narrower tapes than that. Or am I missing something here - is wider better?

[SuperJohnG]

Not sure about width but a lot of people order from Germany. This is a good thread. 

 

 

[SimonD]

They are expensive, no getting around that. I've been using Gerband tapes for my 1st floor timber frame from Passivhaussystems.co.uk You can get window tapes from Siga at airtighttapes.co.uk and Green Building Store sell Tescon Vana and others.

 

One other alternative that I'm using around all my wall to floor junctions and around the window reveals in the old masonry part of the house is Saudatight LQ liquid membrane which can also be used with a geotextile tape for large gaps. I've been buying mine from Platinum Chemicals - Soudatight LQ - Geotextile

[Iceverge]

@Adsibob

 

What are you taping the windows to? Brick? 

[Dudda]

The tapes are supposed to be 60 to 75mm wide (even more) around windows. You're looking for the double split tapes where about 15mm sticks to the window frame and the remaining 45mm gets stuck to the internal airtight layer or wider 100mm tape is used and 85mm is stuck to the brick / concrete / blockwork structure which wouldn't be as smooth as the window frame and therefore needs to be wider to get a better adhesion and allow for plastering over.  

[Moonshine]

5 minutes ago, Dudda said:

The tapes are supposed to be 60 to 75mm wide (even more) around windows. You're looking for the double split tapes where about 15mm sticks to the window frame and the remaining 45mm gets stuck to the internal airtight layer or wider 100mm tape is used and 85mm is stuck to the brick / concrete / blockwork structure which wouldn't be as smooth as the window frame and therefore needs to be wider to get a better adhesion and allow for plastering over.  

 

i have been looking at the illbruck ME508 Duo tape (200mm) to be stuck onto the inside of the windows frames before they go in to the recess, like this

 

 

best price i can find it for is here

 

https://www.sealantsonline.co.uk/ProductGrp/illbruck-me508-duo-membrane-ew-f

 

[Dudda]

The only issue I see with that product is where you've a company doing the airtightness and another fitting the windows. If using normal airtighness tape the airtight company can come at a later date and airtight the whole building. If you're doing the airtightness yourself and are around when the windows are getting fitted that's great.

[Moonshine]

5 minutes ago, Dudda said:

If you're doing the airtightness yourself and are around when the windows are getting fitted that's great.

 

kind of, the window installers have agreed to put the tape on the frame prior to installation, but won't do any other airtightness work which is fair enough and is on me.

 

how do you do the airtightness of a window frame that is already fixed in place?

[Mr Blobby]

2 hours ago, Dudda said:

.. wider 100mm tape is used and 85mm is stuck to the brick / concrete / blockwork structure which wouldn't be as smooth as the window frame and therefore needs to be wider to get a better adhesion and allow for plastering over.  

 

Does anyone ever apply a primer to the blockwork reveal so that the airtight tape has better adhesion?  Like blowerproof paint or even a parge coat before sticking the tape down?

 

 

[Declan52]

10 minutes ago, Mr Blobby said:

 

Does anyone ever apply a primer to the blockwork reveal so that the airtight tape has better adhesion?  Like blowerproof paint or even a parge coat before sticking the tape down?

 

 

The tape I used from gerband required a type of glue that you applied like silicone into y the block work. It was a flexible adhesive and very very sticky.

https://passivehousesystems.co.uk/product/winflex-i-airtight-window-tape/

https://passivehousesystems.co.uk/product/gerband-fortax-6400-airtight-sealant/

 

[Dudda]

2 hours ago, Moonshine said:

how do you do the airtightness of a window frame that is already fixed in place?

You stick the 15mm part of the split tape onto the face of the window frame. This ends up getting covered and hidden by plasterboard or plaster and therefore isn't seen when finished.

[Moonshine]

10 minutes ago, Dudda said:

You stick the 15mm part of the split tape onto the face of the window frame. This ends up getting covered and hidden by plasterboard or plaster and therefore isn't seen when finished.

 

cheers, so ordering the ME508 duo will cover me for if its installed inside the gap, or on the window surface.

[riboid]

I have always used the tescon vana and it comes either split or whole along the 50mm width.  Great stuff and sticks like shit to a blanket.  

[Adsibob]

17 hours ago, riboid said:

I have always used the tescon vana and it comes either split or whole along the 50mm width.  Great stuff and sticks like shit to a blanket.  

So this is the tape I'm looking at, in the 60mm width. @IcevergeI am sticking either to concrete reveals that were cast three months ago, or in most cases to timber frames. The company selling the tape is hitting me with "You may also need this primer" (https://www.ecologicalbuildingsystems.com/product/tescon-sprimer). Do i, or is this just upselling?

[Iceverge]

A primer is the correct choice. 

 

Tapes need a dry and very importantly dust free surface to stick to. Masonry is rarely this without a primer. 

[riboid]

Yeh, always on concrete or any similar substrates, I would apply that primer too.

[Adsibob]

So primer on the concrete, but not on the aluminium window frame, correct?

 

 What about on plywood?

[PeterW]

Primer on rough surfaces only. 

[riboid]

On 28/10/2021 at 14:08, Adsibob said:

So primer on the concrete, but not on the aluminium window frame, correct?

 

 What about on plywood?

The concrete will obviously be dusty and porous, so the adhesion levels will not be as great as say on your aluminium.  I just solvent washed/cleaned before application of this tape and its sticks very well. I did though, after taping up all of my windows, apply a liquid air tightness paint product to ensure it was properly sealed.  Belt and braces.

[Russell griffiths]

I did all my windows without a piece of tape in the entire house. 

Used the illbruck foam and covered in illbruck caulk, the one that comes in the sausage tube. 

Easier to do than tape, probably no cheaper. 

Air tested very good. 

 

I looked at the tape tape and it just looked like a pain. 

[riboid]

3 minutes ago, Russell griffiths said:

I did all my windows without a piece of tape in the entire house. 

Used the illbruck foam and covered in illbruck caulk, the one that comes in the sausage tube. 

Easier to do than tape, probably no cheaper. 

Air tested very good. 

 

I looked at the tape tape and it just looked like a pain. 

 

Problem with the caulk though, with temperature fluctuations it can shrink and move (we use mastics/caulks daily on my maintenance contract), so I would have always followed that caulking with tape.  Your air tightness readings might be ok now, but due to that movement, they may not be so good in a few years, whereas the tape has been engineered to last over 100 years (went to the courses in ireland and glasgow).

[Russell griffiths]

1 minute ago, riboid said:

 

Problem with the caulk though, with temperature fluctuations it can shrink and move (we use mastics/caulks daily on my maintenance contract), so I would have always followed that caulking with tape.  Your air tightness readings might be ok now, but due to that movement, they may not be so good in a few years, whereas the tape has been engineered to last over 100 years (went to the courses in ireland and glasgow).

The word caulk is probably a poor description, it’s the stuff made by illbruck for window sealing. 

Not sure what temperature fluctuations you are talking about this is applied on the inside, where the temperature is fairly constant. 

[riboid]

2 minutes ago, Russell griffiths said:

The word caulk is probably a poor description, it’s the stuff made by illbruck for window sealing. 

Not sure what temperature fluctuations you are talking about this is applied on the inside, where the temperature is fairly constant. 

 

Caulk in itself has a tendency to shrink and move over the years and eventually dry out.  Temperature was probably the wrong terminology.

[James94]

On 27/10/2021 at 15:29, riboid said:

I have always used the tescon vana and it comes either split or whole along the 50mm width.  Great stuff and sticks like shit to a blanket.  

Agree with riboid, this stuff if amazingly sticky. We’ve been using it to tape up our vcl and windows.

Regards. James

 

[Adsibob]

2 hours ago, James94 said:

Agree with riboid, this stuff if amazingly sticky. We’ve been using it to tape up our vcl and windows.

Regards. James

 

Well hopefully the consensus here that it’sa good product justifies the crazy price I paid for it. 90m of the 150mm width tape worked out at £225. It costs almost half as much on the continent, but I was in a rush to get it and so didn’t have time to order it from baunativ.de as that required an intermediary within the EU accepting it on my behalf, and then forwarding it onto me, as baunativ no longer ship to the UK.

 When I add the cost of the primer, this is very expensive. I hope the £20k or so that I’ve spent on insulation, airtightness and MVHR will save me money in the long run.