Buying a house with possible damp?

[Amywmcg]

We’ve seen a house we love - an older terraced house (100 years old) but newly refurbished by a local builder. Everything is really well done however on a second viewing today we’ve spotted some damp patches on the downstairs wall (underneath a chimney). The builder/seller has said if we buy it they will fix the walls and warrant the work- but they don’t think it is damp- they say it is the ‘dabs drying out’. Pics attached of the patches on the walls. Has anyone had something similar? I’m not sure how much of an issue this is- we really love the house. We’d get our own survey done of course but just curious if anyone has proceeded with a house purchase with similar circumstances…

I'd be a bit wary. Chimneys are prone to damp for various reasons. They were usually constructed without any damp proofing underneath as the use of the fireplace would continually dry it out. You can also get water ingress from the top, which again would have been dried out by usage originally. Are there cowls on the flue terminals?
I don't know if drying dabs causing temporary damp patches on plaster are a thing, but I do know that if the bricks are wet then the water will use the dabs as a bridge to the plaster board.
Definitely get a survey, and if using a damp remedial company who charge a small up front fee for a survey then be aware that they will have a vested interest in selling you a chemical damp proof course, which may not actually be necessary but is how they make their money.

Thank you- that’s helpful.

If the chimneys are blocked up at the bottom they should have ventilation bricks in to allow airflow or you end up with damp issues.

’dabs drying out’ is slightly dubious as they dab with browning which dries in minutes and it totally dry in no time.
You did confirm it’s all plasterboarded?

Buying a house and the surveyor has concerns about rising damp from the cellar. High moisture levels were noted on the kitchen wall, front bay wall, and all around the basement. He also had concerns that new timber was laid on top of wet rot timber in the floor (so ceiling of the cellar). He’s recommended I get a damp specialist come in and assess how bad the problem is but the seller has had damp proofing done in 2021. All the areas that have been damp proofed are all the areas that have high moisture levels. Cellar has been tanked. And there are guarantees from the damp proof specialist but these aren’t insurance backed so if the company goes bust, they’re worthless. Seller is claiming they spent £15k damp proofing all the problems. Would anyone be put off by this - my concern is that there is a bigger problem that damp proofing isn’t fixing? It is an old house built in 1890 so I expected some problems but it’s been fully refurbed inside so if the solution is to rip out all the plaster and start again then this will be a problem if the seller doesn’t want to reduce the price. Any opinions would be welcomed…

I would walk away. But if you choose to buy ask for a consequential discount.

Does the cellar have an actual ceiling that prevented the timbers ( the floor of the ground floor) being inspected?
What were the damp works carried out? Was it just tanking the cellar? Tanking keeps the moisture in the wall, unable to evaporate. This can lead to the moisture accumulating and spreading up the wall through the brickwork.
1890? is it solid brickwork?

It wouldn't put me off if that was all of it. I don't think it's dabs, but it might be a bit of condensation- esp if it's very recently plastered.
If you do want it checked, get a specialist old buildings surveyor, not a 'damp proofing company'. And check out the Heritage House website first.
Could be chimney pointing, or inadequate ventilation of chimney or underfloor....