damp internal/external walls, horrible growth under carpet

[lynne]

My son bought a house a couple of years ago from a property developer. Its been renovated on the cheap and the old man who lived there for 60 years had no heating in the house at all. To be fair my son hasnt lived in it much and so its not had any continous heat or ventilation since he's owned it. However, he is now about to move his young family in.

In the rear downstairs room all the skirting boards have rotted. the gripper rods have rotted.
The internal wall, on a damp day, shows a 'tidemark' at about 3 ft high.
Today we pulled the carpet back and there is a horrible brown growth, looks a bit like seaweed, weaving its way under the underlay. I lifted a bit, and it was dry and woody. (today is a dry day).
There is a concrete floor and under the skirting boards on the outside wall is black mould and gunge.
I am puzzled by the damp on the internal wall, which backs onto an open cupboard under the stairs, which strangely, isnt damp.
Is it possible that by using heat, dehumidifier and ventilation we could solve the problem, or is it going to be a new external and internal dampproof course. Would we be advised to get a Building Surveyor in first before doing anything. We dont want to throw good money after bad.

[the specialist]

Hi Lynne

Any chance of u posting any photos on here?

I know how to cure your problem. Where is the house?

Its not just a condensation problem so you will probably need to get a pro in.

[TheDoctor5]

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