Damp in 1830’s Stone House

[Grove Renovation]

I am in need of advice please before I waste any more money trying to fix this problem. Prior to my purchase, this old stone house has had cement strapping pointing applied - I realise this is bad and am in the process of getting quotes to have it removed and hydraulic lime mortar applied. I’m hoping this may go some way to help the problem on the inside where the plasterwork is powdery / very crumbly. Should I be looking to replanted in lime? The main problem I have is some signs of water ingress recently seeping under the skirting board onto the flagstone floor. Externally there are paving slabs and soil right up to the house wall. I plan to remove the strip of paving running up against the wall and dig some of the soil out and fill with gravel. Can anyone advise if this may improve the situation or if not what I should be considering? Thanks

[arco_iris]

First off I STRESS that I am not an expert, I only comment from experience as my own property is pre-1790 (I also own a holiday let of similar construction) - been there, done that. Here's a good website that explains it pretty well:

https://www.heritage-house.org/damp-and ... stone.html

Whatever you do, under NO circumstances be tempted to have a chemical dpc applied that will really b*gger it up.

Other than that you've pretty much answered your own question, though I would also suggest that you examine the roof, eaves & verges - what looks to most people like solid stone walls are in fact an outer stone face, an inner stone face, and what's in between is all sorts of cr*p & detritus chucked in as they went along. This is generally porous, damp emanating at ground level inside could potentially have come from the top and dropped down by gravity. This is why chemical dpc is bad, it forms an impervious barrier and when moisture meets it, it has to flow horizontally taking the easiest route. The cement pointing prevents it going outwards so it comes inwards through the interior wall finish.

And that should under no circumstances be gypsum plaster, if it is hack it ALL off and do it with lime render.

[wes56]

First thing is to post photos of the outside showing full elevation from ground level to eaves.
And photos of the interior from floor level to ceiling.

After raking out the beds and perps use sharp sand mixed with NH lime powder at 3:1 for pointing - and 3:1 or 4:1 for interior rendering to replace the gypsum plaster.
Eamine the backs of the skirting boards.

Can you ID any kind of DPC?
Are the floors solid or suspended?

Dont be cutting any channels or French drains until you've posted the above pics, and been further advised.