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 and http://www.schrijverdampcontrol.co.uk/index.php
coming in this week to have a look.

Any thoughts...?

Thanks in advance

Simon

"chalkstorm" wrote in message
...
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 and http://www.schrijverdampcontrol.co.uk/index.php
coming in this week to have a look.


Thought #1: Rentokil are b***** expensive
Thought #2: It's lack of ventilation and a cold wall. Move furniture out a
bit and improve ventilation


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

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

Thats condensation for sure..

- 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.



Mmm. Must be condensation there also if the plaaster is drier below the
surface.


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 and http://www.schrijverdampcontrol.co.uk/index.php
coming in this week to have a look.

Any thoughts...?

Insulate the wall and leave the trickle vents open.

Thanks in advance

Simon

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.

Given the age of the place, the walls will be solid and hence colder to
the touch. The application of an impermeable coating on the outside will
also prevent one of the ways that walls of this type get rid of moisture
- i.e. evaporation. The proximity of furniture etc will reduce air flow
and convection on the inner wall surface. Installing DG will also remove
any natural ventilation from draughts. These all add up to a classic
scenario for condensation to form on the wall. Its also a vicious circle
in that as the wall gets wetter it will also conduct heat better, and
hence attract more condensation.

The danger is that given time the wall can get saturated and the you get
the risk of wood rot on the back of skirtings, floors etc.

The immediate solutions are adequate heating and ventilation. You need
to minimise water production in the area as well - so ventilating
cooking or washing steam produced near it before it can be a problem.
Not drying clothes over radiators etc.

Another thing to check in many cases (but I suspect does not apply in
yours, since it sounds like you have solid floors), is that there is
adequate airflow under the floor from air bricks etc. This allows the
wall to shed more moisture.

A more lasting solution is to look at ways of insulating the wall so
that you can more easily maintain the inner surface temperature above
the dew point. Your options here are limited to dry lining inside, or
possibly external solid wall insulation.

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

Chances are they will stick a timber "damp meter" on the wall and tell
you its wet, then suggest all sorts of drastic and pointless remedies!



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Thanks all - think you've confirmed what the decorator said really...

I've run a dehumidifier in there for months - and it fills, I empty
it... it fills... and so on.

It rarely gets heated - and rarely used. Better half always wanted
the doors closed at night and when we are at work (fire/smoke etc) -
but that'll change. Will also leave the windows on the vent position,
locked of course.

I like the Shriver system - sounds like it will do the job (after some
research) - and don't really want the upheaval of dry lining or
insulating the walls - but I suppose this is the time to do it (just
means the decorator has to stop what he is doing...) - unless there is
an easy way of doing it... (I'm cr4p at DIY hence my pathetic
questions on here!)

Thanks again

John Rumm wrote:
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.

Given the age of the place, the walls will be solid and hence colder
to the touch. The application of an impermeable coating on the
outside will also prevent one of the ways that walls of this type get
rid of moisture - i.e. evaporation. The proximity of furniture etc
will reduce air flow and convection on the inner wall surface.
Installing DG will also remove any natural ventilation from draughts.
These all add up to a classic scenario for condensation to form on
the wall. Its also a vicious circle in that as the wall gets wetter
it will also conduct heat better, and hence attract more condensation.

The danger is that given time the wall can get saturated and the you
get the risk of wood rot on the back of skirtings, floors etc.

The immediate solutions are adequate heating and ventilation. You need
to minimise water production in the area as well - so ventilating
cooking or washing steam produced near it before it can be a problem.
Not drying clothes over radiators etc.

Another thing to check in many cases (but I suspect does not apply in
yours, since it sounds like you have solid floors), is that there is
adequate airflow under the floor from air bricks etc. This allows the
wall to shed more moisture.

A more lasting solution is to look at ways of insulating the wall so
that you can more easily maintain the inner surface temperature above
the dew point. Your options here are limited to dry lining inside, or
possibly external solid wall insulation.

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

Chances are they will stick a timber "damp meter" on the wall and tell
you its wet, then suggest all sorts of drastic and pointless remedies!


I wholy agree with these comments.

If the room is rarely used, presumably it also is not as warm as the rest of
the ground floor? What is the proximity of the room to the kitchen?

I would be inclined to install a dehumidifier and use this from time to time
during the winter months.

chalkstorm wrote:
Thanks all - think you've confirmed what the decorator said really...

I've run a dehumidifier in there for months - and it fills, I empty
it... it fills... and so on.

It rarely gets heated - and rarely used. Better half always wanted
the doors closed at night and when we are at work (fire/smoke etc) -
but that'll change. Will also leave the windows on the vent position,
locked of course.

I like the Shriver system - sounds like it will do the job (after some
research) - and don't really want the upheaval of dry lining or
insulating the walls - but I suppose this is the time to do it (just
means the decorator has to stop what he is doing...) - unless there is
an easy way of doing it... (I'm cr4p at DIY hence my pathetic
questions on here!)

Thanks again

I posted before downloading this last post.

Seems like you are on the right track.

Good luck.

chalkstorm wrote:
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.

Is the chimney still in use? Sometimes people seal off fireplaces
without providing a proper vent, meaning that damp will build up over a
period of years in the chimney and leach into the surrounding brickwork.

It can take months and months to dry out even with the root cause fixed.

Jim wrote:
chalkstorm wrote:
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.

Is the chimney still in use? Sometimes people seal off fireplaces
without providing a proper vent, meaning that damp will build up over a
period of years in the chimney and leach into the surrounding brickwork.

It can take months and months to dry out even with the root cause fixed.

At this time of year I'd be looking outside for rain penetration rather
than condensation. IIRC the OP has an acrylic coating on the exterior
wall? Good stuff if it's applied well and properly bonded to the
brickwork, worse than useless otherwise

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

On Aug 5, 11:12*am, 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. *

oh dear

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.

oh dear



Any thoughts...?

Thanks in advance

Simon

The simplest option is to use the dehumidifier more. Just alter its
setting. Dehumidifiers have made many once troublesome damp problems
easy to resolve. A conventional 'proper' repair would involve
ventilating the room more, probably heating it more, and maybe
insulating the wall. Dont assume its non-cavity, there are a fair
number of cavity walls from the 1800s about, and CWI is very cost
effective.


NT