Acceptable Internorm window gap?

[alexo]

1 hour ago, MikeSharp01 said:

They cannot sort the bottom gap because of the inward opening window. The problem there is the lack of sill packer - they should not have solved that with expanding foam if not a sill packer, but rather with and insulating block such as sold by Green Building Store then render over and make good. Overall the install looks awfull and the compriband should go all around and match the system requirements from Internorm which will specify depth, recess etc then the Illbruke foam goes behind that from the back. If you paid with your credit card I would put them on notice seek immediate replace / refit from the supplier.

Oh wow is it really that bad!? This is a large reputable firm who do a lot of Internorm installs including passivhauses and have almost 100% positive reviews and I wasn't expecting this.  I've raised the issue with the manager on the project.  He is still claiming everything is fine and that there is a sill packer in there that is the one recommended by Internorm.  He acknowledged the compriband shouldn't be popping out like that and said they'd make good before they finish off outside.  

 

[alexo]

This is the foam they're using.  The project manager claims they always use this on Internorm projects including passivhauses.   It isn't airtight.  They've said they always use it.  Is it just cheap crap? I can't find any data sheets on it. 

[garrymartin]

I don't have any skills to comment on the install, but I can help out with the datasheet.

 

https://eshop.wurth.co.uk/is-bin/INTERSHOP.enfinity/WFS/3108-B1-Site/en_GB/-/GBP/ViewOfferDetail-GetDocument/08921521__ZTD02.PDF?DocumentId=Y12022052402000005507051e27743ae&ProductRefID=08921521%403108-B1&MimeType=application%2Fpdf

08921521__ZTD02.pdf

[alexo]

1 minute ago, garrymartin said:

I don't have any skills to comment on the install, but I can help out with the datasheet.

 

https://eshop.wurth.co.uk/is-bin/INTERSHOP.enfinity/WFS/3108-B1-Site/en_GB/-/GBP/ViewOfferDetail-GetDocument/08921521__ZTD02.PDF?DocumentId=Y12022052402000005507051e27743ae&ProductRefID=08921521%403108-B1&MimeType=application%2Fpdf

08921521__ZTD02.pdf 369.34 kB · 0 downloads

Amazing, thanks Garry.  Unfortunately I do not have the skills to interpret it either 😂

[SimonD]

7 minutes ago, alexo said:

Amazing, thanks Garry.  Unfortunately I do not have the skills to interpret it either 😂

 

I don't think that's an airtightness product. I wonder whether the installers confuse thermal insulation with airtightness.

[MikeSharp01]

It does not stay flexible like the Illbruk one does so if there is any movement if goes with it rather than staying where it was put and creating cracks / leaks. Also I found this video from Charlie Luxton which shows his Internorm window install. At 56 seconds in you can see him talking about a window and you can see how how your should have packer at the base and he goes on to talk about the expanding tape and how that should be fitted and refers to the microcraking you get if you don't use flexible fillers. Worth a look.

 

 

[alexo]

4 minutes ago, MikeSharp01 said:

It does not stay flexible like the Illbruk one does so if there is any movement if goes with it rather than staying where it was put and creating cracks / leaks. Also I found this video from Charlie Luxton which shows his Internorm window install. At 56 seconds in you can see him talking about a window and you can see how how your should have packer at the base and he goes on to talk about the expanding tape and how that should be fitted and refers to the microcraking you get if you don't use flexible fillers. Worth a look.

 

 

Fantastic, thanks Mike.

[MikeSharp01]

Ok so Airseal FM330 from Illbruck "has is a moisture curing expanding polyurethane foam that ideal for use as an air tight gap filler for construction joints. The movement accommodation factor of 35% ensures that the integrity of the seal is maintained." Accommodation factor is not mentioned on the Wurth product (Which I would have a l;ot of time for in other applications - they make good stuff)

[alexo]

5 minutes ago, MikeSharp01 said:

Ok so Airseal FM330 from Illbruck "has is a moisture curing expanding polyurethane foam that ideal for use as an air tight gap filler for construction joints. The movement accommodation factor of 35% ensures that the integrity of the seal is maintained." Accommodation factor is not mentioned on the Wurth product (Which I would have a l;ot of time for in other applications - they make good stuff)

Thanks, I have got some of the Ilbruck FM330 arriving on express delivery tomorrow.  
 

Given that I think it’s unlikely I’m going to get completely new frames with my lack of technical knowledge and lack of ability to argue it, the plan is to use that going forward, and for the 3 already fitted we will dig out as much of the existing foam as possible and refoam with the Illbruck. 

[alexo]

This morning I was reassured by the fitters that no foam would probably be needed on the 2 they fitted today (non-dormers) which led me to believe this problem wouldn't affect all other windows.  After fitting this is what we got.  Again approx 2 cm gap above window board, with the window resting on a grey plastic ledge internally.  This gap is currently letting in a howling gale and the fitters aim to fill it with foam tomorrow, although clearly the amount they can fit in here is minimal so even though they will use airtight foam I'm not confident its going to do much. 

 

It's really clear they're all going to have this problem, so as has been said before there is clearly an error here, I assume the windows are 2cm approx shorter than they should be.  For example it's quite obvious to me the outside pictures show the window ledge screws visible when the frame should sit closer to the cill, which is also unsightly.

 

So my question is, if I go all in on fighting this do I have a case?  Is this enough of a measurement error for me to stop the install and request a resolution such as replacement or a hefty refund without being penalised for stopping the install?  Or is this a grey area?  Am I making too much of a fuss about 2cm gap?

 

@craig or anyone else in the know advice would be much appreciated!

[craig]

5 minutes ago, alexo said:

This morning I was reassured by the fitters that no foam would probably be needed on the 2 they fitted today (non-dormers) which led me to believe this problem wouldn't affect all other windows.  After fitting this is what we got.  Again approx 2 cm gap above window board, with the window resting on a grey plastic ledge internally.  This gap is currently letting in a howling gale and the fitters aim to fill it with foam tomorrow, although clearly the amount they can fit in here is minimal so even though they will use airtight foam I'm not confident its going to do much. 

 

It's really clear they're all going to have this problem, so as has been said before there is clearly an error here, I assume the windows are 2cm approx shorter than they should be.  For example it's quite obvious to me the outside pictures show the window ledge screws visible when the frame should sit closer to the cill, which is also unsightly.

 

So my question is, if I go all in on fighting this do I have a case?  Is this enough of a measurement error for me to stop the install and request a resolution such as replacement or a hefty refund without being penalised for stopping the install?  Or is this a grey area?  Am I making too much of a fuss about 2cm gap?

 

@craig or anyone else in the know advice would be much appreciated!

Dinner has just been put on table, will come back to this.

Edited April 10 by craig

[craig]

The internal cill height difference should have been taken into account. Cill needs removed, packed up and made good.

 

It’s an oversight but it would need to have been resolved either way.

 

External alu cill as expected but I’d expect coloured screws / cover capped screws for fixing.

 

Along top externally, it's a replacement tbh and I’d expect things not to have been considered or a wait see result before finishing. I’d have expected a discussion to have taken place though.

[alexo]

34 minutes ago, craig said:

The internal cill height difference should have been taken into account. Cill needs removed, packed up and made good.

 

It’s an oversight but it would need to have been resolved either way.

 

External alu cill as expected but I’d expect coloured screws / cover capped screws for fixing.

 

Along top externally, it's a replacement tbh and I’d expect things not to have been considered or a wait see result before finishing. I’d have expected a discussion to have taken place though.

Thanks Craig. I will complain again and hopefully I will not be gaslighted this time. Still no acknowledgement of an error

from them.
 

So annoying that we have essentially lost 2cm of view from each window because of this.

[alexo]

Does anyone know what Internorm’s ‘recommended installation methods’ are please? Is there an installation manual or a document I can refer to?

[craig]

They follow GGR guidelines, they’re the same in Europe basically.

[alexo]

21 minutes ago, craig said:

They follow GGR guidelines, they’re the same in Europe basically.

I’m completely clueless on this- what is GGR? Had a quick look. Thought I’d seen someone mention GGF guidelines before but can’t find them either. Is that the same thing? 

[alexo]

This? https://cwgchoices.com/wp-content/uploads/2021/10/the-good-practice-guide-for-the-installation-of-replacement-windows-and-doors.pdf

[craig]

Yes.

[alexo]

45 minutes ago, craig said:

Yes.

Thanks. So Internorm’s recommended installation methods are… the same for all other windows, essentially the minimum allowable standard?

 

So shove them in and foam them is acceptable by that logic?

[alexo]

On 10/04/2024 at 20:31, craig said:

The internal cill height difference should have been taken into account. Cill needs removed, packed up and made good.

 

It’s an oversight but it would need to have been resolved either way.

 

External alu cill as expected but I’d expect coloured screws / cover capped screws for fixing.

 

Along top externally, it's a replacement tbh and I’d expect things not to have been considered or a wait see result before finishing. I’d have expected a discussion to have taken place though.

Hi @craig I’ve just read this back and seen you said along top needs replacement. Missed that before.

 

What did you mean by this? Why does it need replacement? Which image were you referring to? Thanks

[craig]

Misunderstanding, what I was saying was it's a replacement project and sometimes not everything has been taken into account or considered and sometimes it's wait and see what to do scenario after discussions with you if need be.

[alexo]

9 minutes ago, craig said:

Misunderstanding, what I was saying was it's a replacement project and sometimes not everything has been taken into account or considered and sometimes it's wait and see what to do scenario after discussions with you if need be.

Ugh, thanks. I can’t bear the thought of all these lovely frames going to landfill!

This mistake is so unfortunate for everyone involved. The fitters are working really hard trying to fix a mistake not of their own making, with the materials the firm has provided them.
 

I have contacted Internorm to complain about the 4cm gap and to ask if it would meet Internorm’s recommended installation methods to have such a gap and then fill it with non-airtight non-window foam.  
 

They immediately spoke to the supplier and contacted me to say they usually advise and give info on Passive installations but that is not what I had agreed with my supplier, and that using my airtight foam would be a good resolution.
 

 I had naively thought that ‘Internorms recommended installation methods’ that I was signing up for were close to Passiv standards which obviously is not the case.

 

I did ask for and get the supplier to write into the contract that they would fit with compriband, which to be fair to them they have done using ISO chemie bloco. But not to passiv standards. Fitters are using 15/6-15 (15mm wide I think) and putting it right on the front strip of the frame rather than in the middle recess of the frame.  
 

I didn’t specify exactly how it should be used so again, my naive mistake! 
 

And of course the biggest mistake was not going for a firm that specialises in passiv installations.  We did get a quote from one but it was much more expensive and we were at the top of our budget. Of course our installer gave a very competitive quote.

 

And I didn’t think I needed full passiv standard in my draughty old house, but I did want it as close as reasonably possible with compriband. And to have windows that fit! 
 

Oh well, lessons learnt and all that 🙄