On 5 Aug, 11:12, chalkstorm wrote:
Hi all
Been a while since I've posted - only seem to come back these days for
advice.. so please be gentle!
I've got an old house - built in 1880 - and while decorating (he is
downstairs as I type), we have found damp patches on a gable end wall
- at low level in the living room. *It seems to match areas where
furniture has been up close - although there is also some around a
chimney breast - and some in the corner of the room (no furniture
there). *We've dug into the plaster with chisels and it doesn't seem
damp inside - which is odd.

The room doesn't get much use - has had new double glazing and one of
these plastic coating renders applied in the last 12 months. *The
decorator thinks it isn't rising damp (the concrete floors are dry -
and the skirting is fine) - but I'm not sure.

I've got rentokil andhttp://www.schrijverdampcontrol.co.uk/index.php
coming in this week to have a look.

Any thoughts...?

Thanks in advance

Simon

Dear Simon
You would be well advised to ask yourself some searching questions
before spending money on either Rentokil or Schrijver
First Schrijver

How long has that particular legal entity been in buisiness?
Have any of the directors or staff any connections with Dutch
companies offering a similar service with a similar product that went
bust in the last 40 years not once but twice under different names?
Is is possible to cure rising damp by only doing external walls? In
this context what is the logic of not doing internal walls which are
equally founded on soil just as are the external ones!?
Is plastering recommended and if not what reason given that if there
is hygroscopic material present that is the only sensible solution?
Do you trust any company that offers a life time guarantee?
or indeed natural products?
or indeed states "Research shows.." with no references.
Are they members of the PCA/BWPDA?
Does the surveyor have the CSRT?

I could go on at length but by now you will either get the message or
bury your head firmly in the sand and go your own way

Rentokil
Expensive but will pass all the above questions.

What is the problem?

It is either hygroscopic salts in the chimney breast caused by burning
coal over the last century or condensation or lateral penetration. You
have elimnated the latter with exposing dry brick so it is one of the
other two

Is there any black mould? If so that is condensation
Is it by the furntiure? if so others have correctly told you what to
do

I suggest you map the damp and spend your money on a damp meter not a
survey and assess if it is coming and going with the weather - if so
it is hygroscopic
if not and black mould, it is damp

I will let you know what to do when it is identified!
Chris