Damp from concrete under the underlay

[messwithsammy]

Hi
I was trying to look for some help online regarding a damp issur, we bought a house recently and there was a buldge in the floor i thought we would just replace the laminate and that should fix the problem, however the buldge just kept on bigger and started feeling wet, so i cut the laminate to check whats the issue.
and there seems to be alot of sweat between the underlay and the concrete floor.
I doubt its a burst pipe beacuse it affected only one spot on the floor.
the underlay has a gap under the affected area.
I wanted to know if this is normal and if i change and seal the underlay and install the new floor would it be fine or is it a bigger issue.
Thanks for all the help

 

[JP_]

Could be a leaking pipe - was this an extension maybe - push fit radiator connections leaking in concrete maybe?

 

[messwithsammy]

Hi thanks for the suggestion however the radiator pipes are on the wall and its not an extention.

 

[dazlight]

What’s the sub floor?
How old is the house ?

 

[messwithsammy]

There dosent seem to be a sub floor, looks like underlay is directly on top of concrete.
The house was built in the 1950s.

 

[dazlight]

So it’s concrete then. Which won’t have a damp proof membrane. So you need to remove the laminate , let the floor breath for a while then put down a liquid Dpm like ardex DPM1c

 

[messwithsammy]

Thanks for the suggestion, i will probably do that. however its a bit confusing because i inspected the whole floor and its only one spot thats affected and the previous owner said the floor was installed 15 years ago, which makes me think how did it not happen sooner. Also there seems to be some sort of chemical on the floor wich feels slimy to the touch and takes about 10 handwashes to get off once touched.

 

[dazlight]

Could be old adhesive residue.