Roofing help

David_Aldred

Hi - please look for previous posts on here regarding chimney / plaster issues.

From what you are describing the stack is on your side / she has no stack on her side of the party wall and if mid terraced her stack will be on the opposite party wall and so on down the street which is how they were built sometimes rather than back to back.

Moisture evaporating from damp flues brings with it contaminates of the soot - primarily sulphates which once they migrate into plaster produce brown staining that comes and goes with the weather. The plaster will not recover once this occurs no matter how much you play around with flashings / re-pointing / cowlings etc.

Obviously it helps to have the stack pointing / mortar securing pots / flashings / any cowlings to open pots fitted under guidance of Gas Safe registered plumber etc all in good order and out of preferance a damp proof course all the way through the chimney stack brickwork just above where it penetrates through the roof (often in lead or copper sheet and I do not mean flashings tucked into the stack here but a horizontal dpc all the way through the entire masonry). However many houses were built without such a dpc given the design function of the stack was to have a roaring coal fire in it that would keep everything nice and dry.

Liabilty - not a lawyer sorry but there prob people on here who are and things to consider being:
1. It is reasonable that coal fires are generally no longer used these days.
2. That was the way the house was built and not (unless you find something by inspection) disrepair.
3. Both owners on both sides of the party wall since the Party Wall Act 1996 are usually but in some cases not always (for instance London had special rules at one time if I remember -scratching head) jointly responsible for the party wall which woudl include the stack which is integral to it.

Best advice - don't fall out over it - talk to each other and work together to an amicable solution - legally you might (and you need to confirm) be able to shrug it off but it is the stack on your side that is the primary cause by the sound of it so be reasonable - she is your neighbour you do live next to each other. First comment I woudl say is ask her if she would fork out to pay the corresponding owner on the opposite party wall if they came knocking on her door and see what she says.

I would just get somebody to give you some legal advice on the liability side of things as it is outside my scope of expertise but hope the comments help - kindest regards, David Aldred Independent damp and timber surveyor.

David_Aldred

Forgot to mention - with regard to resolving the contaminated plaster - options are to re-plaster to a spec able to hold contaminates within the wall and also be waterproof or waterproof studded memebrane (see Delta or Oldryod or Platon) membrane and dry line with foil backed plasterboard incorporating fully effective vapour barrier. The problem with the simple re-plastering option is it requires a very high standard of workmanship / substrate preperation which is not always forthcoming as plasterers often ignore specs and plaster the way they want to, the plasterer wants paying whilst the wall is still damp and if it does not dry down / degrades again later they blame anyone but themselves.

Sometimes the ceiling plaster adjacent to the stack is also damaged and again will not recover. Check to remove all fine debris wedged between any timber rafters / ceiling spars etc and the stack as such debris will form a sponge of contaminates and then fit foil backed plasterboard but ensure there is a an impervious flexible barrier between edge of plasterbaord and stack. All work to be to full room heights to room of problem and as a general principle (your case may differ so do not rely on this info) extend removal of plaster to at least 500mm beyond fault. Again - hope this helps Kindest regards David Aldred Independent damp and timber surveyor.