Mystery goo

[umborne]

I've stripped some old vinyl tiles from a concrete floor while renovating an old cottage. The tiles were laid about 15 or 20 years ago and most came up easily, the adhesive being dry and brittle. A few were still well stuck down, but about half a dozen came up easily with a runny sticky goo underneath of a reddish brown colour. Any ideas what this could be? My only thoughts are that this could be the result of a leak from a water pipe, but the only possible candidate would be the service pipe between the outdoor and indoor stop cocks (hence a posting to another form). I'm not sure exactly where this runs but a straight line between the two would take it somewhere nearby, although it would then have to pass under an extension built about 20 years ago. Would building regs have allowed this?

 

[Symptoms]

um - more likely the original adhesive never cured in patches so maybe that's what you're seeing.

 

[umborne]

I'd like to think it was that, but these tiles have been down such a long time I'd have thought it unlikely. And why only this patch? If someone has encountered the same phenomenon I'd be reassured

 

[Symptoms]

um - I've seen this before hence my post. Remember, years ago many tiles were stuck down using a trowelled adhesive (not self-adhesive) and the stuff often 'pooled' and didn't go off. Yeh, it could be a reaction to something in the concrete (salts, moisture) but your goo is likely to be old adhesive. Scrape it up, use a moisture meter to check if the floor is wet.

 

[umborne]

Thanks, that's the reassurance I was looking for. I know the floor has been damp because I have tested it before, but I've installed a French drain outside the property to alleviate this, and this patch was well away from the area where damp had been a problem. The adhesive seemed to have cured OK over the dampest part.