External vs Internal sources of water leak in my concrete floor??

gutovicky

Good morning helpful people..

Looks like I'm facing another mini crisis...

There has appeared a large damp area on the carpet in the middle of my lounge.
At first (panicking), I thought it was connected to all the heavy rain we've had recently - but that's crazy right?? - because that would mean the damp was penetrating the DPC in the concrete slab... (assuming I've got one?)......

Next possibility:  my radiator feed & return pipes are all buried in the concrete floors, so possibly/probably some of these have developed leaks....
However, the large damp patch is well away from any pipe-runs.....

Can water leaking from these buried radiator pipes build up within the concrete slab over time - and then show up in odd places like this??
Is this what often happens?? 

Any knowledge & ideas would be great.
Thank you, Vicky

MikeJXE

I presume you have checked overhead ?

gutovicky

Yes, MikeJXE  -  definitely bubbling up from below somehow!!
Cheers, V

GrumpyDil

When was the property built? Earlier concrete floors may not have any damp proof membrane. 

MikeJXE

GrumpyDil said:

When was the property built? Earlier concrete floors may not have any damp proof membrane. 

A good point

Do you know at what level the water table is in your area considering we have had a lot of rain ?

FreeBear

But you have already got another thread going about the same problem - https://forums.moneysavingexpert.com/discussion/6417314/im-in-panic-mode-ch-radiator-pipes-leaking-within-concrete-slab

Copper pipes buried in concrete is never a good idea. The cement attacks the copper, and over time (20 years or so), pinhole leaks form. You either replumb the heating so that no copper pipe is buried in the floor, or dig the whole lot up and replace. Some insurance companies will cover the cost - Read your policy very carefully for the exclusion clauses.

And yes, the pipe could well have been leaking for months before you notice.

gutovicky

Thanks for taking the time everyone - much appreciated!

Yes FreeBear, sorry, I have got 2x threads overlapping, but looking at different aspects of the same problem - wasn't sure where to post...

GrumpyDil & MikeJXE, the property is a bungalow built 1970...     
Will it have a DPC under/within the concrete slab do you think?
And:
The property is actually situated halfway up a hill from the main town, so is +/- on sloping terrain.
However, the land is quite clayey - so retains a lot of water - and apparently is prone to random springs 'surfacing' [...!!...heard that from a local a few years ago...]. 

Any further feedback/ideas would be good.
Vicky

GrumpyDil

@MikeJXE may have a better idea but that's around the date that damp proof membranes started being included in concrete floors so yours is right on the edge. 

I don't know how to tell if a floor has a DPM but there are paint on solutions that might help solve the issue if it turns out you don't have one. 

stuart45

The DPM was part of the mid 60's Building regs, so a 1970 built will probably have one. They were sometimes damaged, especially in the early days. After heavy rain the labourers would put holes in them to let the water out.

gutovicky

Oh my days!!!
So even if there is a DPC, it could have been damaged from the outset...

So, in-a-nutshell, although my 30+ year old copper rad pipes in the slab ARE highly suspect, this water/leak problem COULD be a gurgling-up of groundwater from under the sub-base....
How to tell the difference?

Of course, over the next day or 2, I shall monitor my water consumption [taking repeat readings taken from the property's Water Meter] to check whether I have unexplained water usage...

Are there any other simple checks or observations I could make??

Thanks for all your help, Vicky  

 

stuart45

If you think your central heating pipes are leaking, and you have a header tank in the loft, tie up the ball valve and see if the water level in the tank drops.