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It doesn’t sound like a
particularly interesting topic, however a quick search on
the worlds favourite internet search engine will show that
in some circles rising damp is a very hot topic indeed.
The trouble is that it appears that it could indeed be
some type of religion or god; does it exist, or doesn’t
it? The truth of the matter is that rising damp does
indeed exist in one form or another, but it is often
misdiagnosed, or you can often pay for expensive treatment
that really isn’t necessary.
Rising damp in buildings
may be defined as the vertical flow of water up through a
permeable wall structure, the water being derived from
ground water. The water rises through the pores
(capillaries) in the masonary by a process loosely termed
"capillarity." In other words the masonry acts
like a wick The common causes are deterioration due to age
and bridging of a damp course with internal concrete
floors, renders or external paths and earth levels (a damp
course is specifically designed to avoid the possibility
of rising damp- it is built of a matter of course in all
new buildings).
If your house does have a
problem (something we will discuss later) then it can
cause the following symptons:
For inside walls
- Paint does not adhere to
the wall.
- Wall paper lifts and
stains appear on the walls.
- Plaster flakes away,
feels soft and spongy, bubbles and white powder or
crystals appear.
- Skirting boards and
floor boards rot.
For outside walls
- Mortar frets and falls
out between bricks and stonework.
- Stains or white powder
appear on walls.
These problems are mainly
aesthetic problems only, however it is conceivable that
structural damage could result from extensive rising damp,
and of course a damp mouldy environment could pose a
health risk to people.
Obviously if you have any
of the above symptoms then it is possible that your home
is suffering from rising damp, and it would be advisable
to get an ‘expert’ in to look at your home. However
this is where you will face a major problem; who is an
expert , and who is just a ‘cowboy’ out to diagnose
you with the "worst case of rising damp that he has
ever seen, which can only be solved with the most
expensive treatment on the market"? Unfortunately
there are a lot of companies out there who have targets to
meet and profits to make, and the way they do this is by
over zealous diagnosing, and charge you hefty fees for
carrying out work that may, or may not, fix the problem.
The major problem is that
any damp-proofing salesman that you employ to look at your
home will use a ‘rising damp meter’. These meters are
supposed to measure the moisture in materials, however
what they actually do is measure the electrical
conductance. The idea being that the better the
conductance (the ease at which electricity flows) the
higher the water content. However these meters can only be
calibrated for one material, and that is usually timber.
So they will give reasonable results for wood and possibly
some plasters, but for bricks, wallpaper and concrete they
will give readings that are way too high. Thus they can be
used (by unscrupulous salespeople) to indicate that you
have rising damp “because the meters says so” when in
fact you have a perfectly normal wall.
In summary if you can
visibly see a problem with your wall, with obvious signs
of damage due to water or salty tide marks then you may
have a problem with rising damp, and you will need to try
to find a reliable expert to come in and look at your
problem. However be very, very wary of any ‘expert’
who has been employed to do a general survey of your
house, or indeed comes around offering a free check up of
your building. If they pull out one of these moisture
meters, jab it into the wall a few times and declare that
you have a major problem, then it is entirely possible
that they are a commission based salesperson trying to
extract money from you.
Generally, if the wall
looks okay, it is okay. If it looks like it is damp,
mouldy or has tide marks on it, then you have a problem
with moisture, condensation, or rising damp in your home,
and you need to investigate things further.
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About
The Author
Alastair
Taylor runs a DIY website that tries to
give the consumer the truth about home
improvement jobs. Visit http://www.whatprice.co.uk
to saves yourself time and money. |
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