Damp on Internal Wall

[Dave Smith]

I have recently bought a 1930s semi detached house. It is only 1 street back from the sea front and I have been lead to believe the water table is quite high in this area. We have started to decorate but have found some damp on the internal wall between our house and the neighbouring property.

I believe the wall is a 9" solid wall. I have had the floor up and can see a small amount of standing water about 60cm under the wooden floor. There appears to have been a chimney removed in this room, but the original DPC which seems to be felt looks to still be in place.

The damp is rising to about 40cm above the level of the suspended wooden floor. I'm considering trying one of the DIY cream injection DPC systems but am wondering if this would be effective or if there is something else I can try.

 

[primetime]

I'm in a similar situation where I need to do some more exploring. I have no standing water, it's bone dry underneath but the party wall foundation was damp (now drying out hopefully). It sounds in your case like bridging causing the damp. Have you checked the air bricks and that you have good cross flow under the house? Is the ground work external to the wall above your floor level? If the DPC is intact there seems little point in adding another. I'm against injection, creams etc after doing quite a bit of research and seeing the results of such treatment on a section of my own home. Others have had success but it seems to generally be unnecessary.

Have a look at the youtube channel by Peter Ward, you should be able to get some insight to your problem from some of the ones he encounters. A lot of times the remedy is simple - ventilation or lowering external ground work.