damp caused by concrete floor placed in victorian terrace in the 80s

[stwerbshouse]

hello,

I'm currently in the process of renovating a victorian terraced house in bristol, and our biggest issue so far is 'rising' damp in the living room. we recently had a doorway cut between the living room and kitchen, which has allowed us to uncover a cross section of the concrete floor in the living room (the house is built on a hill, so the living room is one step higher than the kitchen).

When viewing from the kitchen, we can now see that there is a damp proof membrane in the floor, but it appears to be tucked back into itself rather than attached to the wall. In the bricks we have removed in the knocked through doorway, we have not yet found the damp proof course (we haven't removed bricks from below the kitchen floor level, so the concrete dpm must be above the dpc in the walls.

any ideas what our next step should be? we're hoping to remove a channel of the concrete floor around the walls rather than the whole floor, but i'm not sure what to then do with that channel (limecrete?)

please and thank you to anyone with any advice

photos attached:

 

[a twig]

Is there any evidence of a DPC on the external face of the brick walls?

 

[a twig]

Assuming the darker patches of plaster are your damp that’s going a long way up by the door in your first pic which makes me think there might be other causes than damp from the ground

Presume you have done the usual checks of rainwater goods etc to make sure your downpipes aren’t just dumping water into the foundations

 

[stwerbshouse]

Is there any evidence of a DPC on the external face of the brick walls?

Assuming the darker patches of plaster are your damp that’s going a long way up by the door in your first pic which makes me think there might be other causes than damp from the ground

Presume you have done the usual checks of rainwater goods etc to make sure your downpipes aren’t just dumping water into the foundations

external face- i can't see an original but i can see a previous injection treatment that was done in the 90s. It may be my untrained eye that can't find the original, I'll post a photo!

yes the damp is going a long way up that wall- all rainwater goods were entirely replaced when we first bought the house a year ago, along with some work on the roof- it is definitely not that. the damp has continued to rise over this time, so this has made no difference. The mains water supply does run under the hallway next to this wall but we can't see any leaks here. Lots of the neighbours have had 'rising damp treatments' so it seems to be a consistent problem for all/many of the houses in our row.

this is the other side of the wall with the most damp (the hallway side). we drew a line this time last year and you can now see how much it has risen since then.


this is the external wall of the living room and hallway


this is a floorplan - the only walls with a problem are the living room walls- the wall next to the stairs has no problem (suspended timber floor in hallway) and the kitchen walls have no problem either (concrete floor here)