UPVC windows. Are the large gaps between my bay window sill and brickwork causing the damp on the wall inside?

[DaveAF]

Hello.

3 years ago we had 2 new upvc bay windows fitted by an established company in the London area.

The ground floor window has sealant between the sill and the brickwork, the first floor window does not.

We have damp on the first floor interior wall below the window but not on the ground floor wall below its bay window.

There are large gaps between the first floor bay window sill and brickwork and 2 packing strips can be seen from street level on both sides of the bay window. (cant get photos to upload to site).

I have several questions and will appreciate any thoughts. 

1. Am I correct in thinking that this is how water is getting in? 2. Is it normal to seal gaps under a ground floor window sill but not a first floor sill?

3. Should I ask the installers to come back and seal the gaps? 

Regards

DaveAF

Edited November 14, 2022 by DaveAF
Cant see the photos i attached. Maybe too many.

[Redbeard]

1. Almost certainly

2. No.

3. Yes. And perhaps ask them why they thought it was reasonable to leave the job unfinished.

 

Was there no damp *whatsoever* before the window swap? If that is the case you may wish to get a quote for remedial work and forward that to the window co.

 

I am not au fait with attaching pics on this site but probably shrinking them as much as poss will help.

 

Edit: Just realised this was 3 years ago. Had you not noticed the gaps till now? The installer could (a) say 'too late', (b) argue that had they been informed immediately after the installation the damage you may now ask them to repair would either not have occurred or would be less severe

Edited November 14, 2022 by Redbeard
Noted install was 3 yrs ago

[Big Jimbo]

I doubt the window company will be interested after all this time.

[ProDave]

In a previous house I owned, the gap was sealed with linseed oil putty.  In just a few weeks after it was fitted, the local birds had removed all the putty from the upstairs windows.  I assume they felt downstairs was just too exposed to danger for them to do the same.

 

Could yours be the same, it was sealed originally but has been removed by local wildlife?

[DaveAF]

  On 14/11/2022 at 13:30, ProDave said:

In a previous house I owned, the gap was sealed with linseed oil putty.  In just a few weeks after it was fitted, the local birds had removed all the putty from the upstairs windows.  I assume they felt downstairs was just too exposed to danger for them to do the same.

 

Could yours be the same, it was sealed originally but has been removed by local wildlife?

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I dont think so. The white sealant under the ground floor bay window has an elastic feel to it when prodded. 

[DaveAF]

  On 14/11/2022 at 13:27, Big Jimbo said:

I doubt the window company will be interested after all this time.

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Maybe if I point out that one window is sealed and the other isn't would that qualify as an inconsistency in installation? 

[DaveAF]

  On 14/11/2022 at 11:44, Redbeard said:

1. Almost certainly

2. No.

3. Yes. And perhaps ask them why they thought it was reasonable to leave the job unfinished.

 

Was there no damp *whatsoever* before the window swap? If that is the case you may wish to get a quote for remedial work and forward that to the window co.

 

I am not au fait with attaching pics on this site but probably shrinking them as much as poss will help.

 

Edit: Just realised this was 3 years ago. Had you not noticed the gaps till now? The installer could (a) say 'too late', (b) argue that had they been informed immediately after the installation the damage you may now ask them to repair would either not have occurred or would be less severe

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Yes windows were fitted 3 years ago.

I know it sounds daft that I never noticed the gaps before but under the exterior window is a strip of what i think is a flashing material that is painted shiny black but it might be decorative. Not sure.

As the house and window walls are bright white its very hard to see the gaps under the window sill unless you are looking for them as they blend into the black flashing material and the area directly under the sill is in permanant shadow from the overhanging sill. 

I wouldn't have expected them to repair the interior damage to the wallpaper.

Just knowing that its not normal practice to seal under one window and not another might be enough to get them to come and seal it. We'll see. 

Thanks. 

[markc]

How old is the property? What windows were in previously? Even with a gap under, water should drip off the sill and not run underneath, or certainly not enough to cause damp walls

[DaveAF]

Its a 1930s mid terraced 3 bedroom house. Previous windows were upvc and had been in since 1999.

The gap is hard to see because of the black flashing but if you zoom in you can see the 2 packing strips just under the sill. Every other house on the street has their under sill gaps filled.

I just don't understand why this hasnt been filled when the other bay window they fitted was filled. 

If I was to have the gap filled could it do any harm? 

[markc]

I don’t think the water is getting in because of the gap, rain would need to be blown horizontal and pretty constantly to cause any trouble. The sill doesn’t appear to have a drip catcher and (might be distorted image) sloping down towards the building so water is pulled in rather than being blown in.

the black is the old sill and any water landing on that should run outwards and down the wall. I really think there is more going on here than just an un filled gap.

Edited November 14, 2022 by markc

[Radian]

  On 14/11/2022 at 22:35, markc said:

I don’t think the water is getting in because of the gap, rain would need to be blown horizontal and pretty constantly to cause any trouble. The sill doesn’t appear to have a drip catcher and (might be distorted image) sloping down towards the building so water is pulled in rather than being blown in.

the black is the old sill and any water landing on that should run outwards and down the wall. I really think there is more going on here than just an up filled gap.

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But surely you've said it all: the rain running down the window runs over the edge of the plastic cill and follows it horizontally into the inside of the wall. Fill the gap with a decent flexible PU sealant  - so the water stops at the outside - and that will cure the problem.

[markc]

  On 14/11/2022 at 22:41, Radian said:

 

But surely you've said it all: the rain running down the window runs over the edge of the plastic cill and follows it horizontally into the inside of the wall. Fill the gap with a decent flexible PU sealant  - so the water stops at the outside - and that will cure the problem.

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You are right, the engineer in me just likes to get to the bottom of why rather than just cure a problem

[DaveAF]

  On 14/11/2022 at 23:17, markc said:

You are right, the engineer in me just likes to get to the bottom of why rather than just cure a problem

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A few more snaps to give a clearer picture of the environment.

First pic shows both bay windows in place. Guttering above top window and downpipe to the left. If water was leaving the gutter above the top window and entering the wall at the sides of the top window wouldn't there be damp marks on those internal walls shiwing its passage down? 

Second pic shows one side of the internal damp wall under the upper bay window. There is no damp on the internal walls to the sides of the upper bay windows, only beneath. 

Third picture shows a view of the upper bay window sill on the outside. Same wall as internal damp wall picture. 

If these pictures show anything of interest regarding the source of the damp ingress please comment. Thanks. 

Edited November 15, 2022 by DaveAF
More information. Please note tgat picture upload isnt working.

[DaveAF]

Pictures upload not working. 

[jack]

  On 15/11/2022 at 08:20, DaveAF said:

Pictures upload not working. 

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What's happening when you try? Are your pics too large (as in file size)?

[DaveAF]

  On 15/11/2022 at 10:45, jack said:

What's happening when you try? Are your pics too large (as in file size)?

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File size is 1.50mb. I select 3 from my files but they dont upload. Accompanying post text does upload. 

[Conor]

  On 15/11/2022 at 12:41, DaveAF said:

File size is 1.50mb. I select 3 from my files but they dont upload. Accompanying post text does upload. 

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You're a new user, you dont have the right to upload yet. Maybe @jack can help?

[jack]

  On 15/11/2022 at 12:55, Conor said:

You're a new user, you dont have the right to upload yet. Maybe @jack can help?

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I'm not aware of there being limitations on new users uploading, plus he managed to upload one yesterday.

 

  On 15/11/2022 at 12:41, DaveAF said:

File size is 1.50mb. I select 3 from my files but they dont upload. Accompanying post text does upload. 

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Size seems fine.

 

Try going to where you have the file saved, then dragging and dropping them from there into the post where shown in the editor:

 

 

 

[DaveAF]

  On 15/11/2022 at 10:45, jack said:

What's happening when you try? Are your pics too large (as in file size)?

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Is posting text, images and editing posts best done on a desktop computer rather than a mobile device? 

[jack]

  On 15/11/2022 at 16:51, DaveAF said:

Is posting text, images and editing posts best done on a desktop computer rather than a mobile device? 

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I always use a desktop when photos are involved, so perhaps yes?

[HughF]

  On 15/11/2022 at 16:51, DaveAF said:

Is posting text, images and editing posts best done on a desktop computer rather than a mobile device? 

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Absolutely, It’s painful on a phone (although I’m doing this on iPadOS)

[DaveAF]

  On 14/11/2022 at 22:41, Radian said:

 

But surely you've said it all: the rain running down the window runs over the edge of the plastic cill and follows it horizontally into the inside of the wall. Fill the gap with a decent flexible PU sealant  - so the water stops at the outside - and that will cure the problem.

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Can you recommend a decent flexible PU sealant to fill the gap under my bay window? 

[Radian]

  On 16/11/2022 at 08:46, DaveAF said:

Can you recommend a decent flexible PU sealant to fill the gap under my bay window? 

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Everyone seems to have their own favourite and I'd be pleased to see other suggestions, but for this job I'd probably use Puraflex.

[gaz_moose]

soudal silirub lmn is the stuff to use.