Damp/Condensation issues - Should this be here?

[PollyMolly]

Hello, hoping for some pointers. I have recently moved into a 1904 semi detached property with some big damp issues. We have major condensation problems inside but the house is severely lacking ventilation and we are starting work to resolve it. All problems are on the inside of the external wall. The path is way too high and needs dropping but we also suspect drainpipes are going straight to ground. The gravel in front of the bay window is also to high and on digging down, we found quite a big trench filled with additional gravel. Underneath the gravel, glued to the brickwork is a black impermeable barrier. The brick behind it is very wet. I’m assuming this really shouldn’t be there and that we need to dig that out. Removing this, along with dropping the path, sorting the drains and adding a couple of extra air bricks should resolve the sub floor moisture issue? any thoughts?

 

[Cubist]

Are there suspended wooden floors in the ground floor rooms or are they solid?

 

[PollyMolly]

They are suspended

 

[Cubist]

In that case your plans overall seem good to me. Air-bricks will help to prevent problems with the wooden floors but it would be worth verifying your proximity to any sources of local flooding. It's worth noting too that surface/ground water levels have been, and still are, exceptionally high at present and this could be contributing to your problems. External drainage routes around the perimeter of the house will play a vital role and during the work you're doing outside you would be wise to ensure that these direct water downhill and away from the property.

 

[PollyMolly]

Thanks for that and the additional pointers, it’s reassuring to know we are on the right lines. Lots of work to do!