Wasn't expecting this...what next?

[roofmog]

2017-11-15 14.36.00

• roofmog
• 15 Nov 2017

Lifted some old vinyl flooring to replace with new, and discovered this. Although there is a lot of mould, there is no actual sign of water. It appears to follow the line of where a new concrete slab was joined to the original many years ago when an extension was added, which leads me to suspect that there was a problem joining the two damp proof courses.

Short of digging up the whole floor what can I do next.

 

[noseall]

What exactly is the problem? All I can see is floor levelling compound and some black spot mould - the latter you would probably find in a majority of homes, beneath a non-breathable floor covering such as vinyl.

 

[roofmog]

That's kind of reassuring. My fear was that the damp proof course had failed and that rising damp was causing the mould.

 

[catlad]

There has been a leak from one of the appliances at some point and its festered under the lino.
Scrub it with bleach and put some new flooring down.