Condensation or penetrating damp?

[kevin_robson]

We have a bay that is getting mould on the inside. Recently it has also been wet to the touch. Double glazing was fitted a couple of years ago which may be a contributing factor. Is this condensation from the inside or penetrating damp from the outside? We get a few bits of condensation elsewhere but not this bad.
http://kjpublic.dynalias.com/bay/IMG_4716.JPG
http://kjpublic.dynalias.com/bay/IMG_4717.JPG

In addition since the double glazing was fitted we have had mild cracking, which I was told was just settling. Could this be related? You can see where the bricks have cracked as well as the plaster.

http://kjpublic.dynalias.com/bay/IMG_4718.JPG
http://kjpublic.dynalias.com/bay/IMG_4719.JPG
http://kjpublic.dynalias.com/bay/IMG_4722.JPG

Outside of house is:
http://kjpublic.dynalias.com/bay/IMG_4720.JPG
Note there are no problems on the lower bay.

Only other thing is the mortar is quite powdery on the upper bay - is this the more liklely cause?
http://kjpublic.dynalias.com/bay/IMG_4723.JPG

Also worth mentioning that the paint is not actually peeling off, which I'd expect if it was penetrating.
Thanks in advance

 

[JohnD]

tape a piece of clear plastic tightly to the wall. See if moisture forms on the wall side or the room side.

p.s. your picture are huge. Have you got a picture of the outside of that bay, showing the DPC in relation to the paving or flowerbed, and also the airbricks?

 

[Shytalkz]

Ref the cracks, as these are on the panel between the ground and first floor windows, but none below the ground floor windows, the likelihood is that:

• the packing between the ground floor windows is inadequate, leading to relaxation of the structure above onto the frames; and/or
  the ground floor windows do not have steel bay poles in them between the frame sections.

Have the external cracks only appeared since the Upvc windows were installed, as there's some repointing where the cracks are?

 

[anobium]

Double glazing can be a factor for condensation occurring on internal walls.
If prior to fitting d/g you had condensation forming on the single glazed windows, all you will do by fitting d/g units is move the excess moisture to the next coldest surface which will now be the external walls.
What you need to do if this is the problem is to remove the excess moisture from the building by means of extraction , ventilation or additional heat.

 

[kevin_robson]

Thanks Chaps,
I'll try to cover all of those points.
I should have made it clear I was talking about the upper bay, not the lower one, so I dont suppose the DPC is the culprit. However, the house has NO airbricks in it.

The windows do have the steel supports, however it does look to me to have sunk a little. I was told this was normal settling when I queried it. I do not believe that the external cracks were present when they were fitted. However, various bits of repointing have been done so it is difficult to say what has gone before over the years. Is this a major cause for concern, or normal settling as suggested?

I also understand (and believe this probably is) condensation, I just want to confirm it isn't coming through the mortar or elsewhere. Is the mortar likely to be a factor or is it difficult to tell? I will try the tape trick suggested earlier.

 

[Robbie uk]

Basically as anobium says. that is definatley condensation. Lack of airflow usually the culprit. movement of air is paramount. I have seen this many times when houses have had double glazing fitted.

 

[^woody^]

Yes most likely condensation related.

Basically, the double glazing has removed a cold surface for air to condense on, and so it moves to the next cold surface which is the wall.

It may not be a simple case of increasing air flow as how is this done in practical terms?

Also, the solid brickwork can become damp and whilst not itself allow actual penetrating moisture, it is damp enough to facilitate condensation by lowering the dew point. The external cill overhang seems very short in places - which will allow rain to drip onto the brickwork beneath and make it colder

Although the common answer is to balance heating and ventilation, it may not be a practical solution. The best thing to do would be to fit an insulating plasterboard to the inside to remove the cold surface and increase ventilation - there does not appear to be any trickle vents in the frames

 

[kevin_robson]

Thanks all. Looks like you've confirmed most of what I thought. I had planned to insulate somehow but have been unable to find anything suitable. Could someone post a link to some suitable insulating plasterboard that will bend around the bay please? Otherwise I've seen lots of insulating paint - does this really make any difference?

Finally, nobody has really picked up on the state of the pointing or the cracks in the wall? Can I discount the pointing and stop worrying about the cracks that the settling of the double glazing have caused?

Thanks again

 

[Shytalkz]

Finally, nobody has really picked up on the state of the pointing or the cracks in the wall? Can I discount the pointing and stop worrying about the cracks that the settling of the double glazing have caused?

Thanks again

Erm, I think you'll find that I did! See few posts above...

 

[kevin_robson]

Yes, I better rephrase that.
"Nobody seemed massively horrified about the cracks .................."

I'm not sure. They've clearly been repointed as you say, but it wasn't by us. I dont remember the cracks in the external wall, and I'd be amazed if they were there and the double glazing company never mentioned it, just to cover their own backside.

The cracks on the plaster inside deffo were't there pre-double glazing and happened during installation or shortly afterwards. As I said we were told it was settling.

How bad is this, or am I worrying unneceserily? Should I get them back out? And is it related to the damp in any way?

Thanks

 

[Shytalkz]

It's not an uncommon problem with replacement windows in bays. There are steel posts (bay poles) which should be installed in instances such as this, but quite often aren't.

The Rehau upvc window sections themselves are not load-bearing. If the load above ends up on them, they deflect, distort the opening casements making opening and closing difficult; in extreme cases, it can end up with load transference onto the glass, which can bow, or even crack. This is the most potentially serious fault.

Another issue is that of packing between the window frames and the surrounding structure. If this is inadequate, then the structure will gradually relax. If there are baypoles, then the movement should stop at some point, without too much damage occurring.

Then there's the possibility that the bay was inadequately propped whilst the windows were being installed.

Whichever of these it is, it should not have happened. If you revert to them, they will probably try and rely on the smallprint in their contract, which says something along the lines that they will not be responsible for cracking. That is patent bóllocks: if the bay has cracked, it has moved as a result of inadequacies in their installation procedure and they need to a) pay for repairs to the cracking and b) ensure that it will not return. If that means there are no baypoles and they need to install them, so be it.

I've just been involved as an expert on a very similar installation: no baypoles, gradual and continuing movement, resulting in the casements jamming and the glass bowing. By the time my and the legal fees were paid by them, plus the cost of repairs, the installers were in a vastly negative money situation. Had they done the work at the outset, they wouldn't have been in the situation, but they denied that black was white for a long while before I was instructed.

Invite your installers back for their comments in the first instance, then take legal advice if they don't (as is extremely likely, unfortunately) sort it for you.

 

[kevin_robson]

Oh.........
That wasn't quite the response I was hoping for, but thanks a lot all the same. I'll see what they say.

If they held their hands up, Realistically what would I be expecting them to do? If I assume that the windows have the supports in them and dont need replacing, would they just be expected to remortar round the cracks? Or does the bay need lifting up again?

Is all this gonna result in a tick in the 'have you ever suffered from subsidence' box on a future insurance quote?

Thanks

 

[Shytalkz]

If it is just the case that they didn't pack it up properly, or prop it adequately, then the settlement should be finite and patching the cracks will be fine.

It's not subsidence, so no need to tick that box

 

[kevin_robson]

OK, thats good to know anyway. I'm always wary of putting anything structural on pen and paper with insurance companies.
I plastered the internal cracks about a year or so ago, but they've come back. Whether that means its going to be continuous or whether it just hadn't found its final resting place I dont know.
All the openings are fine so far though.

So I should push for confirmation that it has supporting rods, confirmation it is properly packed, and get them to replaster inside and repoint outside, and leave at that? Anything else?

 

[Shytalkz]

Depending on how you did the repairs, they could have shrunk and then reopened, which would not be an indicaiton of continued movement.

Ask them for written confirmation that it's got baypoles first off and how it would have been packed up. If they state categorically that they are installed, then tell them the cracks that are there are beyond what would be reasonable disturbance and tell that you expect them to come and repair them (properly ).

If there aren't baypoles, there should be and they need to do a complete reinstall.

Packers should be like this:

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• Shytalkz
• 16 Apr 2008
• 1

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