Home made wadrobe problem.

I have been doing DIY for 40 years, I can do anything but plastering. This summer I finished my third floor to ceiling wardrobe/cupboard.
I have lived in this 2 up 2 down terraced house, built 1894, for 30 years. Very little except the main joists is original.
The new cupboard is very damp on the inside, soaking the wallpaper that was there before the cupboard. The cupboard is on the front wall of the SW facing house, 9" brick with a lathe and plaster finish.
The wall has never been damp before and indeed the area under and to the right of the window in the same wall is still totally dry.
The cupboard construction is as I have done before a floor to ceiling frame of 2" x 2" designed to perfectly accommodate 3 pairs of doors from B&Q a 6' one and on top a 3' one.
My wife said that she found the inside of the cupboard cold as the winter came on and now it is very cold in there even though the room has central heating.
So I conclude that.
1) I have a condensation problem or 2) I have a ventilation problem or both.
Is their an easy solution, I suspect not. I assume that I have to force ventilate or heat the cupboard, this is not appealing.

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I'm assuming the damp is on the external walls? A couple of options. You may need both...
You need to ventilate the cupboard so it isn't colder than the room. Using open louvre doors might be one way. If the cupboard is going to get piled up with things that restrict ventilation (e.g. cloths piled against the wall), then this isn't going to work.
Insulate the external wall(s) of the cupboard. 25mm of Cellotex or Kingspan would probably do.
Probably not relevant to a wardrobe, but if the cupboard was to be a larder of something else which benefits from being cool, you could make sure the door (and all other openings between the house and the cupboard) are reasonable air-tight, provide thermal insulation in the cupboard walls and door, and ventilate the cupboard to the outside. My parents have a larder constructed this way and it works well on a North facing wall.
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Andrew Gabriel

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Why didn't the Corporation Compulsory Purchase your slum 50 years ago?
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They were probably too busy explaining to you that the bath is not for storing the coal in in yours, I would imagine.
.andy
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From other responses, it sounds like condensation resulting from the creation of a cold cupboard.
However, as an addition "long shot" are you 100% convinced that there are no water pipes (maybe lead?) buried in the lath & plaster wall? Could you have drilled through one when fixing the frame for your wardrobe?
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I think that you've done a good job, but have made a very effective cold cupboard. It's possible that there is some penetrating damp through the brickwork, especially as the wall is SW facing, although the clue is that there was no apparent damp there before. Even so, I would do some obvious checks on the outside wall - for example is there a rainwater pipe that might be leaking, gutter overflowing, etc.? Could there be any crumbled brickwork? Worth a check.
However, if the cupboard is damp more or less uniformly across the back, then my money would be on condensation and lack of ventilation. The problem is that the heat loss through a solid 9" brick wall is quite substantial, so the action of building a cupboard has been effectively to reduce heat reaching this space from the room. It would be interesting to put a thermometer inside and see how much cooler it is than the room - I'd bet a good 10 degrees C. You don't say what you used to make the rest of the cupboard, but most of the composite sheet materials are pretty reasonable insulators, so in effect you are making a cool box next to the wall.
You say that not much in the house is original. Have you fitted double glazing and generally draughtproofed by any chance? If so, in the winter, you may have quite low ventilation in the house in general, leading to relatively high humidity. All that it then takes is a cold surface, and bingo. The air will certainly be finding its way into the cupboard, and my bet is condensing on the cold wall at the back.
Assuming you are satisfied that the outside wall is OK, then I think the next step would be to insulate the back of the cupboard. To do this, a good solution is polyisocyanurate foam, aka Celotex or Kingspan. This comes in 2440x1220mm sheets from builder's merchants in various thicknesses. 50mm is a very common one and readily available. This would take the heat loss through the wall almost down to modern house standards. Probably 25mm would be good enough to achieve the desired effect if you can get it. Expect to pay about 15 to 18 a sheet for it.
The Celotex web site especially has some good application notes on how to use this material. It can be cut easily with a knife (an old bread knife is good) or a saw. It's foil covered on both sides.
I think that what I would do is to fit pieces of Celotex in the back of the cupboard, temporarily taping in place with masking tape. Check that it has the desired effect, and if so do a more permanent job. I would make a simple wooden frame at the back of the cupboard, fit the Celotex inside it, sticking it to the wall and then fit a thin panel of your choice over the top supported on the frame. Make sure that you seal the edges of the Celotex before panelling over it to prevent room air from reaching the cold wall behind. That would lead to condensation, which you don't want.
I am pretty sure that this will resolve the problem, but otherwise fitting small vents top and bottom might be necessary - I'd try without first.
Depending on the size of the cupboard relative to the room - i.e. if you have covered a fair amount of the wall with it, you may find that the room feels warmer.
.andy
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In uk.d-i-y on Tue, 30 Dec 2003 03:05:20 +0000, Andy Hall
[...] }>The new cupboard is very damp on the inside, soaking the wallpaper that }>was there before the cupboard. The cupboard is on the front wall of the }>SW facing house, 9" brick with a lathe and plaster finish. } }I think that you've done a good job, but have made a very }effective cold cupboard. It's possible that there is some }penetrating damp through the brickwork, especially as the wall is SW }facing, although the clue is that there was no apparent damp there }before. Even so, I would do some obvious checks on the outside wall }- for example is there a rainwater pipe that might be leaking, gutter }overflowing, etc.? Could there be any crumbled brickwork? Worth a }check.
Yes I have done that, I am convinced that it is not any form of leak. I had one of those in the other corner of the room years ago and that was fixed by reslating the roof. I failed to mention that the dampness is very uniform over the whole of the inside of the outside wall.
}However, if the cupboard is damp more or less uniformly across the }back, then my money would be on condensation and lack of ventilation. }The problem is that the heat loss through a solid 9" brick wall is }quite substantial, so the action of building a cupboard has been }effectively to reduce heat reaching this space from the room. It }would be interesting to put a thermometer inside and see how much }cooler it is than the room - I'd bet a good 10 degrees C. You don't }say what you used to make the rest of the cupboard, but most of the }composite sheet materials are pretty reasonable insulators, so in }effect you are making a cool box next to the wall.
There isn't much of the rest of the cupboard, it is only 16" deep, being built around the doors, and in a corner means there is only doors and one end panel of thin pine T&G cladding.
}You say that not much in the house is original. Have you fitted }double glazing and generally draughtproofed by any chance?
Oh yes.
}If so, in the winter, you may have quite low ventilation in the house }in general, leading to relatively high humidity. All that it then }takes is a cold surface, and bingo. The air will certainly be }finding its way into the cupboard, and my bet is condensing on the }cold wall at the back.
Low ventilation? None is closer to the mark, I was extremely relieved that when I had the gas boiler replaced after 22 years service the installers insisted on better ventilation.
SWMBO has a permanently cold hands and feet, and has ensured over the years that there are no draughts at all. We even have a double entry cat flap. I went and bought a CO monitor as I am/was concerned about the ventilation. It is snug.
}Assuming you are satisfied that the outside wall is OK, then I think }the next step would be to insulate the back of the cupboard. To do }this, a good solution is polyisocyanurate foam, aka Celotex or }Kingspan. This comes in 2440x1220mm sheets from builder's merchants }in various thicknesses. 50mm is a very common one and readily }available. This would take the heat loss through the wall almost }down to modern house standards. Probably 25mm would be good enough }to achieve the desired effect if you can get it. Expect to pay }about £15 to £18 a sheet for it.
That is what I needed to know, thanks.

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OK, well there's your clue.

So you will probably want to think about only 25mm Celotex to minimise loss of depth.

There you go, you are setting up the conditions for condensation.

Certainly if it's a conventional flue model, this is essential. Not having adequate ventilation will lead to CO production. Less critical if it's a balanced flue - then the ventilation is typically for the compartment in which it's installed.

Had you thought about something like heat recovery ventilation? Vent Axia make these among others. The idea is that you bring in and exhaust air simultaneously through separate ducts but via the same machine which sits in the loft, running continuously but at a very low rate. The air leaving exchanges heat to the incoming, warming the air. This way you get ventilation without creating draughts.

You're welcome.

.andy
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Please let your wife out.
ZD
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