Damp in the floor, suggestions?

[Guitar_man]

I put two objects on a patch that was registering high levels on the hydrometer, and when I removed them it appears to have gone black (see pic) indicating damp is getting sucked up. Which would account for the high level on the hydro.
Do you have suggestions for a course of action here? What could be causing it? Can I ignore it and perhaps add a damp membrane to the floor or does it need other attention? Thanks all,

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• Guitar_man
• 31 Mar 2014
• 1

 

[Deluks]

Where is it? kitchen, bathroom? Ground floor? What is it? Concrete on hardcore, no dpm?

 

[Guitar_man]

Downstairs. The damp is next to an outside wall. No idea what's under it, but it is concrete. Wall doesn't seem to have rising damp, but it is a stone wall outside, from the 1880s, so no DPM. Outside wall also looks OK. I stuck the hydrometer on the floor, 80%. The room does suffer from damp in the cold and rainy Cornish weather. So perhaps it is all coming up through the floor. Would an epoxy DPM fix it or would the damp just go up the wall instead?

 

[Deluks]

Dunno if it would fix it or not, digging it all out and redoing the floor would though. Then it's done and you don't have to worry about it.

 

[Guitar_man]

Im not so sure, interesting problem this.
Laid a screed in the kitchen today at 4pm. 2hrs drying time. At 11.00pm it looked like this. Ok, its cornwall so i would expect it to dry in about 4hrs..

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• Guitar_man
• 2 Apr 2014
• 1

Looking from the breakfast room it looked like this.

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• Guitar_man
• 2 Apr 2014
• 1

I checked out next doors property, currently empty with the heating on?, then noted that the drains are right next to my external wall where the problem is. Perhaps a dodgy drain is causing water to flow and cause the damp. Would make sense as the water would flow down that wall as the kitchen is lower than the breakfast room. There was also a lot of ivy on that wall to, i have since removed which was perhaps sucking up water.
I will lift up the neighbours drain when it rains and see if its working next..