Rising Damp? in shared covered alleyway.

caswellcat

Our home built circa 1880, has damp in the side wall. This wall is in a shared covered alley, which is not open to the elements. The house next door has damp in its wall too, so my neighbour tells me.

We have lived here 12 years, and could see that the house had been damp proofed at some point, we could see where they had drilled the holes. No paperwork on this.

We accept that it may need redoing, the plaster inside is starting to blow, and we can see some salts on the wallpaper. No mould. No smell.

We have replastered the wall about 5 years ago, during renovations, but the damp has penetrated. Had the wall repointed last year.

My concern is that something - drains/water supply is causing the damp to penetrate here. The water supply/sewage for a least 4 houses goes up this alley/access.

Can the waterboard help?

The wall seemed dry all summer, but after the first heavy rain it was noticeably damp.

I have seen posts during my research suggesting an independant surveyor. (Sarah Beeny recommends this too!)

Where can I find one and how much should I expect to pay?

Any advice much appreciated.