Cavity Wall Insulation Cold Wall

LindaMary

We had our 1940 3bed Semi insulated a few years ago. They did all walls apart from the front one. They said they could not do this as it was stone-faced on the ground floor with pebbledash to the first floor and any gaps could cause problems. They also fitted a huge vent through the wall as we had a gas fire in the front room and said we needed it (always been a gas fire there)
It's always been a cold north facing room but gradually the condensation problems are getting worse. No condensation on the windows but very cold and wet on the inside of the front facing wall! No mould but the painted paper feels wet and is coming away from the wall. I run a dehumidifier during the winter and this helps.
My question is because of the insulation not being done on this wall is it the cause of the problem and how can we solve the problem? Any energy savings are cancelled out by running the dehumidifier!
Many thanks

new_owner

The condensation is because you are producing to much water into the air. Showers, gas, drying clothes, breathing etc all introduce water into the air.

Ventilation will be the better option.

the water is on the walls because its condensing on a cold surface. Warming the surface will stop the water condensing on it but it will condense somewhere else.

Find where the major source of water is coming from and address that. i.e. Shower but no extractor fan or drying clothes on radiators.

llandyrnog

As this wall is the only one not insulated and north facing it is obviously the coldest and most prone to condensation. so you need to stop the warm moist air from condensing on the cold internal wall face. If you can afford to lose the space, construct a timber 3X2 studding approx 40mm from the wall and fill with 70mm celotex insulation. fix a visqueen vapour barrier on the studding to stop the warm moist air getting to the wall surface and then plasterboard and skim. Window boaerds will have to be extended and any sockets and switches will have to be repositioned. Sounds expensive, I know, but will solve your problem.