Damp Proofing Question

Ongoing damp issues with removal of a chimney stack in victorian house

Hello I am hoping you can help me. I own a ground floor flat and am having ongoing damp patches emerge. I have been told that this was because when the Victorian house was converted into two flats, the builders removed the chimney and in the first floor flat put in a cupboard and downstairs covered the fireplace up. Both areas are now damp with black mould, which I understand could be a condensation issue but have also been told it is penetrating damp is well. It looks like in the upstairs flat, part of the wall in the cupboard has had plasterboard put up in some parts, which is probably I am guessing not allowing the wall to breathe properly and therefore causing further problems? What is the best one to solve this? There is what looks like is an outside vent on the external wall where the first floor cupboard is located and I have been recommended to block it - but is this advisable? What is the best way to resolve this? Understand that I will probably have to hack the wall back and start again, but obviously want to resolve the cause first.

In the same room, I also have rising damp, and am thinking that as there are vents on the outside wall at ground level, these could be getting blocked as rainwater accumulates there in a courtyard and we have had very wet weather recently. Again if anyone could please advise?

Last thing, do DPC work and insulating internal walls on Victorian properties?


Joseph - thanks for the info. I did ask about having a vent put in the room but was told by another builder that with the chimney stack that it was not an air flow problem and that it was stagnant water coming through? It is very bizarre as appears in patches in the middle of the wall and going upwards - I would think when it was converted if the owners didn't do a proper job when it was removed, then it is likely there would be rubble in the stack. Is it costly to put a vent in and remove any rubbish or am I better off removing that section of the wall and starting again? Thanks

Also there was damp on the other side which was coming from the upstairs bathroom, and I have been told that when some areas of the bathroom were re-tiled that the wall was very damp? Is there any way now I can tell how damp the wall is without removing the tiles? Thanks

2 Answers

Hi there
First thing - do not block any vents, these only help. I take it there is an internal vent corresponding to this, the plasterboard not helping the wall to breathe should not be a problem. Although not the way I would plaster a wall, but should still not cause a problem. Vents outside need to be cleared and protected against any water penetration as this will cause major problems. Have a concrete gully surround fitted easy job, your part of the chimney needs an air vent internally and externally as the soot inside the chimney could be condensing and causing damp. Another problem could be when the top chimney was taken down the rubble fell down into yours and has been drawing up the damp. Only way to know this is to put the internal vent in and have a feel around inside and try and clear through the vent.
DPC does work in Victorian properties as does insulating each for their own job. Do not insulate a damp wall unless you have solved the damp problem and water proofed rendered first. Insulation boards should only be used to help against condensation issues on cold exterior walls in your property.
Enough going on here to seek the advice of a competent damp proofing company to have a visual look.
It should not be a costly job you only have to kango through a hole 9 inches by 9 which is not hard, and then pull the rubble through. About half a days work - you would need a survey on the tiled wall with a surveymaster protometer.

Answered 27th Apr 2013

Trident Damp

Member since 26 May 2011

just phone any competant builder who is soveriegn approved for damp proofing like ourselves and you would have honest reliable answer vertually straight away , detailing what would need doin to rectify the problem, if black mould from condensation issues please make sure you have 100mmm extraction fans on timer situated in kitchen and bathrooms areas to prevent this and make sure your not wasting your money on other things that may not even be the cause


Answered 20th May 2013

Eddie Mount Building and Roofing Services

Member since 8 May 2013

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