Damp chimney breast on Victorian terrace - neigbour issues

[r1cho]

Hi there,

Hoping someone can help here! We're in the process of selling our Victorian mid terrace, and a number of people viewing the property are being put off by a damp patch that has appeared on one of our walls upstairs (nothing recent, its appeared over the last few years and we've lived with it).

We have had the local damp specialists out to look at it and they have quoted approx £1500 inc VAT to get it sorted using a newton mesh cavity system and replastering. The wall has the original lime plaster underneath a decorative wallpaper finish (paper will have to be removed of course).

According to the specialists, the source of the damp is due to the adjoining chimney breast that belongs to our neighbour (this particular stack is single sided only, facing into their property and they use a wood burner in winter with no liner). Apparently the specialists reckon the parging and residual soot will have absorbed moisture over the years and it is this that is leaching into our plasterwork).

I have discussed the issue with the neighbour a while back and he stated that whilst they too get damp patches, they are not too bothered as they just keep painting over it. They of course are not selling and any good surveyor will find it very quickly even if we did just paint over - so we need it sorted asap.

So my questions are:

- does the neighbour have to contribute given that its their stack, not ours that is causing the issue?
- if so, how do I go about making them do something about it? What is the process?
- is the quoted Newton system the best way forward to solve the problem? Is it acceptable to use this technique on a period property - it feels like a way of removing symptoms rather than fixing the source of the issue as such (a la chemical damp course 'solutions' that some renovation specialists seem to frown upon).

For info, the stack has already been reduced in height at some point in the past, and has had the pots removed and replaced with a slab of concrete, elevated by bricks to allow the smoke to escape.

Many thanks for any advice you can provide.

Richard

 

[jeds]

It may be sooty deposits and leaching but it's much more likely to be due to condensation. Unlined chimneys burning wood can create huge amounts of condensation. This would be worse at the top of the stack rather than the bottom, and particularly so if the stack is exposed on one side - which I think is what you are saying. In reality there's not a great deal your neighbour can do about it without fairly extensive work so if you want to resolve it quickly your going to have to tackle it from your side. Newton Lath will do it but £1500 sounds a lot to me. It's only a case of fixing the stuff and replastering. I would have thought it would be a couple of days work for a decent builder or plasterer and shouldn't cost more than six hundred quid.

 

[joe-90]

It's condensation. I see it all the time. If you want a quick fix simply use a stain block and paint over it.

Cost about a fiver.

 

[r1cho]

Thanks for the replies. Looks like a simple fix then. Just one thing - if its condensation from burning wood then why does the stain continue to grow during the summer - when no wood is being burnt and when it tends to be warmer and drier outside?? Seems counter logical - unless this is due to the salts and hygroscopy?? Thanks!

 

[Nige F]

I`ll do it for £605 - that`s £600 for the newtonite /replaster and a fiver for joe`s decorators bodge There is no vat

 

[jeds]

The principle cause is condensation which results in chemical staining. Once it gets in it is difficult to shift. Stainblock (the ultimate bodge) might work but more often than not it only works VERY temporarily.