On 17/07/2019 13:35, Dan Green wrote:
Hi all,

Can anyone explain what kind of damp this is and what might be causing
it? There is nothing amiss or damaged on the outside of the building that
could account for it so I'm at a complete loss as to what the underlying
problem could be. Here's a pic:


http://oi66.tinypic.com/1zzgvn4.jpg

Could be condensation, but also the ground level outside could be close
to the DPC. You may also get splashback from the hard surface.

(I had a similar problem here, which in the end I tracked down to a down
pipe from the gutter. It went straight into the ground, but did actuall
appear to be connected to the waste water pipe - stick a hose in the
gutter and it ended up arriving at the septic tank.

In the end I had a dig to investigate, and found the builders had
effected a transition from square downpipe, to 110mm soil pipe by
stopping the downpipe a bit above the soil pipe and "sealing" the gap
with a carrier bag! So a proportion of the water soaked straight into
the ground right next to the wall. So I figged a proper gully with trap,
and let the pipe empty into that. Replaced the rotten floor timbers, and
made sure they were not pressed right up against the wall this time.
Been fine since.


--
Cheers,

John.

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