My GF and I bought our first house in April 2007. The house has a basement conversion (two approx 14'x14' rooms, one approx 10'x6' room), which (we were told at the time of purchase) is tanked.
We recently noticed some 'chalky' patches appearing on the walls - we attributed this to cheap paint! However, a couple of days ago I opened a cupboard in one corner of the basement and found what looks like damp behind some blankets - the skirting board has turned black and moldy and the wall is dappled and yellow.
I don't know how long ago the cellar was tanked or who did the work. I don't know what method was used to either - all I know is that the guy who we bought the house from told us we wouldn't be able to use long nails to hang pictures on the walls - I assume because this would damage the tanking.
In any case, we are now stuck with the damp and understandably want to fix it ASAP (before any more damage is done) and without breaking the bank. From my explanation is anyone able to infer what level of tanking might have been installed, what we might need to do to fix the issues and how much it might cost?
Worst case: the whole cellar needs to be fixed - what are my options and how much is this going to cost?