What are my next steps with this damp?

[dpm_dpmartin]

Hi all,

I've recently bought a small house to renovate and one of the things that I've been working on is removing all of the 1970s wallpaper (from every room).

In the dining room the wallpaper came down at the weekend, it was really thick and multi-layered stuff, and I found some areas where the plaster appeared damp (visually and to the touch).

You can easily see this in the picture here... it's in each corner. This wall shown adjoins the next house in the terrace (the terrace is on an incline) and the house next to the wall where the damp can be seen is higher than this house.

I have a damp meter - Brennenstuhl gadget that I have faith in - that reads 12% in the non-damp bits above, and a humongous 25% in the damp corners that you can easily discern!

12% on the scale is "low".
25% on the scale is "high".

Is it time for me to call the Ghostbusters (some kind of damp experts)?

I'd add this following information, which I hope might also be useful - the house has been unoccupied since early May 2015 and the heating will have been off all that time. There is some ventilation in the house, via a vent or two, but there won't be much. I've had the heating on a fair bit since taking ownership a couple of weeks ago.

I'm not against spending £s to rectify this, I want to pass on a good home for someone when this project is done, I'm just curious what my next sensible steps should be. Any advice will be appreciated.

 

[ree]

Perhaps the three walls shown have all had previous remedial work - at least re-plastered (possibly with the wrong plaster) to a height of say 600mm? Possibly a useless DPC has been injected in the party wall?
Perhaps plastic sheet tanking is present?

At the moment, you can see classic condensation shapes in the lower inside corners - however, penetrating damp and condensation can exist in the same place.

Its possible that the skirtings are fungal damaged due to the damp exposure, its also possible that the neighbour's side of the wall has damp signs.

Is the floor in the pic solid or suspended?

You should carefully examine all the lower walls, esp party walls, in the house. Do any kit base units back on to this party wall?

Typically, you at least have to hack off plaster to a height of 1000mm and perhaps renew the skirtings. Re-render with a sand and lime mix at 3:1 or 4:1.

What did the mortgage surveyor say? Were any D&T certs transferred to you?

Pics of the front & rear elevations might help?

Leave trickle heating on 24/7.

 

[dpm_dpmartin]

Thank you. The floor is solid.

There isn't currently a kitchen installed, but I do not think there is any damp where the kitchen would be. It just appears to be this room and I am hoping it is something that might resolve through adequate heating and ventilation. We are going to have to wait a few days now, though, as the Central Heating Engineer is now half-way through installing a new boiler.

No mortgage and no survey... solid little terrace which we understand might (will?) have its problems, we're happy to spend to rectify the issues that it has, but sometimes we just welcome the advice from here as to what we should be doing. In this case, it feels like - get the heating on and wait-and-see? If no improvement, get an expert opinion and evaluate?

 

[catlad]

I would dryline the walls with insulated plasterboard.