Damp Fireplace walls

[StoneHouse91]

Hi All,

Currently installing new joists, insulation and flooring in living room. I've fitted new telescopic air bricks to helps the space get more ventilation and the old fireplace had loads of rubble in it so I've dug that out, and have removed two bricks in the hearth bit to ensure when the new floor goes down air can circulate through as well.

The chimney has been removed the floor above. The damp marks have not changed since removing the false wall infront of it.

This wall goes against the neighbours, I fear the water is coming through the sub floor (which it does when it rains - I'm installing a French drain in a few months) but we're on a slant so I don't think this can be the only issue / don't understand why it's soaking up this high. I imagine the neighbours must hav an issue as well but they're elderly and I don't sense they'll want to rip their house apart to investigate.

Is there anything I can put on the brickwork to help stop the water staining coming through as much? Would 'stormdry' resolve this issue?

 

[ree]

Stonehouse,
Being on a slope, as you seem to understand, can be a problem with ground water coming downhill.
AFAIK: there's no definitive remedy?
The French drain might help but it depends on the direction of the slope & how deep the original house footprint was cut into the hillside?
The interesting things in your case are why is it presenting now? And why, if thats the case, only at the fireplace?
Removing the fender wall hearth soil was good practice - in fact, why not remove the fender wall entirely.
All your joist tails will need capping with DPC material but perhaps you've already done this.
Massive amounts of through ventilation is great for keeping down humid crawl space air & less chance of further timber rot.

If you have time, it would be interesting to see inside and the outside of your project?