I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. Is this the case or am I mis-
remembering ? (if there is a limit then it could be coming from
somewhere else).

Secondly, if it is rising damp, what's the best remedy? I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

Cheers chaps

On May 12, 6:25*pm, GMM wrote:
I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). *The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. *Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. *The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. *I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): *I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. *Is this the case or am I mis-
remembering ? *(if there is a limit then it could be coming from
somewhere else).

Secondly, if it is rising damp, what's the best remedy? *I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

Cheers chaps

I wouldn't trust an estate agent to know the difference between
rising, penetrating, and arrived-on-a-bus damp.

Four common causes of damp are condensation, penetration, leaks and
rising.

Causes off the top of my head:

Condensation - poor ventilation, poor insulation, inappropriate use of
the building

Penetration, damaged pointing, ivy, wrong building materials

Leaks - pipes (water and drainage), gutters.

Rising damp - bridged damp courses, cavities full of junk

(or combinations of)

In most cases, the building once worked ok, but something went wrong -
you find something, you fix it.

I might investigate if installing that deck has damaged a drain.

On May 12, 6:25*pm, GMM wrote:
I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). *The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. *Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. *The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. *I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): *I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. *Is this the case or am I mis-
remembering ? *(if there is a limit then it could be coming from
somewhere else).

Secondly, if it is rising damp, what's the best remedy? *I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

Cheers chaps

Yes you are right. I have DIY used chemical injection very
succesfully. You can hire all the gear from local toolhire places.
You could get somone in but they charge lots for what is
straightforward work, if tedious.

There are various chemicals. The spirit based ones smell for ages
afterwards.
I fancy they work slightly better than the water based ones. (Though
you might not get them now with this VOC regulations thing coming
out.)

The most expensive bit is putting all back afterwards. Skirtings,
flooring plastering, kitchen units, plumbing, wiring etc. All can be
affected.

I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: Clearly the deck
was installed after the built, so i reckon there's a connection....

GMM wrote:
I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. Is this the case or am I mis-
remembering ? (if there is a limit then it could be coming from
somewhere else).


Even that is pushing it. Mostly three to four bricks unless its stopped
from escaping outwards

Secondly, if it is rising damp, what's the best remedy? I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

Injection works if the injectant (sp?) gets everywere it needs to.

Tanking the inside with a waterproof render works as well Or both together

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

I'd say there is another problem.
Cheers chaps

On May 12, 6:25*pm, GMM wrote:

I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). *The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. *Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. *The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. *I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): *I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. *Is this the case or am I mis-
remembering ? *(if there is a limit then it could be coming from
somewhere else).

Its never going to rise beyond that

Secondly, if it is rising damp, what's the best remedy? *I know

First things first. So far there's no evidence that its rising damp.
Most such cases are condensation, not rising.


chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

Identify the cause first. More heating, more insulation, more
ventilation, or a dehumidifier all can improve or resolve
condensation.


It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some

Hopefully the sellers have more sense.


feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

Cheers chaps

the cost of the usual misdiangnosis of rising damp, replacement of
plaster, injecting water/cream/etc.


NT

GMM wrote:
I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. Is this the case or am I mis-
remembering ? (if there is a limit then it could be coming from
somewhere else).

a metre is the recognised maximum height of rising damp, so ten courses is
easily within this measurement.
Also, although you can see ten courses outside, there could be earth inside
underneath the wooden beams


Secondly, if it is rising damp, what's the best remedy? I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?


DPC cream is the preferred method now and yes, it does work

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.


Then don't let something minor like this put you off, people often run away
screaming at the thought of dampness of any kind, yet it is one of the
easiest things to put right - the major thing that people have an aversion
to is the length of time damp walls can take to dry out, often months, even
after treatment

On Thu, 12 May 2011 10:56:34 -0700 (PDT), GMM wrote:

I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: Clearly the deck
was installed after the built, so i reckon there's a connection....

+1

Which way do the deck boards drain, into the wall? Check by pouring
water onto it. Even if it drains the right way there will be splash
up from the deck onto the wall, is the level of the deck the same as
the floor (skirting) inside?

Having said all that I'd be surprised if an extension only a few
years old doesn't have cavity walls so how is the damp on the outer
leaf getting through to the inner one...

--
Cheers
Dave.

GMM wrote:
I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: Clearly the deck
was installed after the built, so i reckon there's a connection....

Ah. I missed the deck..

Watersplash off a deck can soak the wall immediately above. It its only
single brick that will show up.

On May 12, 8:00*pm, "Dave Liquorice"
wrote:
On Thu, 12 May 2011 10:56:34 -0700 (PDT), GMM wrote:
I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: *Clearly the deck
was installed after the built, so i reckon there's a connection....

+1

Which way do the deck boards drain, into the wall? Check by pouring
water onto it. Even if it drains the right way there will be splash
up from the deck onto the wall, is the level of the deck the same as
the floor (skirting) inside?

Having said all that I'd be surprised if an extension only a few
years old doesn't have cavity walls so how is the damp on the outer
leaf getting through to the inner one...

--
Cheers
Dave.

Good point Dave

The deck level is higher than the skirting (about halfway from there
to the bottom of the window), so water coming off the deck would be in
the right place. The reason I hadn't really considered this is the
cavity issue - I wouldn't expect it to get through to the inner leaf.
I wonder if that means the construction of the wall is wrong (even if
the damp could be solved by modifying the deck somehow)?

GMM wrote:
On May 12, 8:00 pm, "Dave Liquorice"
wrote:
On Thu, 12 May 2011 10:56:34 -0700 (PDT), GMM wrote:
I might investigate if installing that deck has damaged a drain.
I suspect there could easily be something in this: Clearly the deck
was installed after the built, so i reckon there's a connection....
+1

Which way do the deck boards drain, into the wall? Check by pouring
water onto it. Even if it drains the right way there will be splash
up from the deck onto the wall, is the level of the deck the same as
the floor (skirting) inside?

Having said all that I'd be surprised if an extension only a few
years old doesn't have cavity walls so how is the damp on the outer
leaf getting through to the inner one...

--
Cheers
Dave.

Good point Dave

The deck level is higher than the skirting (about halfway from there
to the bottom of the window), so water coming off the deck would be in
the right place. The reason I hadn't really considered this is the
cavity issue - I wouldn't expect it to get through to the inner leaf.

depends how much mortar was put in the gap. Or indeed batts. They carry
water too

I wonder if that means the construction of the wall is wrong (even if
the damp could be solved by modifying the deck somehow)?

En el artículo
roups.com, GMM escribió:

I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years).

Sounds as if the extension might be open on three sides, so will be cold
in winter, which would cause condensation. Something to consider
anyway.

I'm in a similar property to that you describe - Victorian with a
single-brick-depth extension on the back which is open on three sides.
Needless to say, this is the bathroom, so it was very damp. Had to have
the floor relaid with a new DPC, the walls drilled and re-injected then
covered with a DPC membrane, then dotted-and-dabbed, then tiled. Now
OK.

--
(\__/)
(='.'=)
(")_(")

On 12/05/2011 18:56, GMM wrote:


I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: Clearly the deck
was installed after the built, so i reckon there's a connection....

Any timber ledger plate fixed to the wall should be spaced 10m away to
prevent water pooling there, deck should have a slight fall away from
wall.

What way are the boards laid? Parallel to the wall or at right angles?

--
Dave - The Medway Handyman www.medwayhandyman.co.uk

On Fri, 13 May 2011 08:11:53 +0100, The Medway Handyman wrote:

Any timber ledger plate fixed to the wall should be spaced 10m away ..

What bolts do you use to get that spacing?

--
Cheers
Dave.

On Thu, 12 May 2011 23:52:41 +0100, The Natural Philosopher wrote:

The deck level is higher than the skirting (about halfway from
there
to the bottom of the window), so water coming off the deck would
be in
the right place. The reason I hadn't really considered this is
the
cavity issue - I wouldn't expect it to get through to the inner
leaf.

That's always assuming it is a cavity wall. I'd expect it to be but
might not be.

depends how much mortar was put in the gap. Or indeed batts. They carry
water too

Aye, and with the deck so far up unless there is really good
ventilation underneath the outer wall below the deck won't dry
particulary quickly. Are the vertical edges of the deck blocked or
"decked" over?

Maybe removing an outer brick in the affected area to see what is in
the cavity would be a good idea? Below deck level so the new mortar
when it's replaced isn't so obvious.

--
Cheers
Dave.

On 13/05/2011 08:11, The Medway Handyman wrote:
On 12/05/2011 18:56, GMM wrote:


I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: Clearly the deck
was installed after the built, so i reckon there's a connection....

Any timber ledger plate fixed to the wall should be spaced 10m away to
prevent water pooling there, deck should have a slight fall away from wall.

What way are the boards laid? Parallel to the wall or at right angles?


I was looking at a house last night where, although the board supports
were at right angles to the wall, the front "facing board" (or whatever
you call the one that covers the gap) would clearly prevent a free flow
of air. That and the sunken air brick out front was enough for me to
give it a thumbs down.

I've seen a lot of these Victorian terraced houses where paving and
successive layers of concrete at the front have created a new ground
level, and adjoining houses have followed suit. Then the council
pavement is laid to that level and before long you have a whole sunken
terrace. Then sometimes solid floors are put in and a whole set of new
problems arise.

On 12/05/2011 18:25, GMM wrote:
I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. Is this the case or am I mis-
remembering ? (if there is a limit then it could be coming from
somewhere else).

Secondly, if it is rising damp, what's the best remedy? I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

Cheers chaps

A bit of reading that you might find useful:

http://www.safeguardeurope.com/pdf_d..._damp_book.pdf

Colin Bignell

On 13/05/2011 08:26, Dave Liquorice wrote:
On Fri, 13 May 2011 08:11:53 +0100, The Medway Handyman wrote:

Any timber ledger plate fixed to the wall should be spaced 10m away ..

What bolts do you use to get that spacing?


Very long ones :-(

I meant 10mm :-)

--
Dave - The Medway Handyman www.medwayhandyman.co.uk

On May 13, 8:11*am, The Medway Handyman
wrote:
On 12/05/2011 18:56, GMM wrote:



I might investigate if installing that deck has damaged a drain.

I suspect there could easily be something in this: *Clearly the deck
was installed after the built, so i reckon there's a connection....

Any timber ledger plate fixed to the wall should be spaced 10m away to
prevent water pooling there, deck should have a slight fall away from
wall.

What way are the boards laid? *Parallel to the wall or at right angles?

--
Dave - The Medway Handymanwww.medwayhandyman.co.uk

They're kind of oblique, so I suppose that counts as end-on - I
suppose that could lead to water channelling to the wall if the fall
was wrong. I didn't look at the ledger but my recollection was that
there was no free space immediately against the wall. I sort of hope
it is a decking defect if we end up with the place as it would be a
lot simpler to adjust a deck than to rebuild the wall!

On May 13, 8:30*am, "Dave Liquorice"
wrote:
On Thu, 12 May 2011 23:52:41 +0100, The Natural Philosopher wrote:
The deck level is higher than the skirting (about halfway from
there
to the bottom of the window), so water coming off the deck would
be in
the right place. *The reason I hadn't really considered this is
the
cavity issue - I wouldn't expect it to get through to the inner

leaf.

That's always assuming it is a cavity wall. I'd expect it to be but
might not be.

depends how much mortar was put in the gap. Or indeed batts. They carry
water too

Aye, and with the deck so far up unless there is really good
ventilation underneath the outer wall below the deck won't dry
particulary quickly. Are the vertical edges of the deck blocked or
"decked" over?

Maybe removing an outer brick in the affected area to see what is in
the cavity would be a good idea? Below deck level so the new mortar
when it's replaced isn't so obvious.

--
Cheers
Dave.

Now that really is testing my memory - I think it was decked rather
than brick, so I guess it would allow reasonable ventilation. Not
that it would be sufficient if the deck is channelling water directly
to the wall whenever it rains, as TMH suggests.

A bit tricky to take a brick out of a house when viewing but I think
that might be an early job if we end up buying it.

On May 13, 4:58*am, Mike Tomlinson wrote:
En el artículo
roups.com, GMM escribió:

I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years).

Sounds as if the extension might be open on three sides, so will be cold
in winter, which would cause condensation. *Something to consider
anyway.

I'm in a similar property to that you describe - Victorian with a
single-brick-depth extension on the back which is open on three sides.
Needless to say, this is the bathroom, so it was very damp. *Had to have
the floor relaid with a new DPC, the walls drilled and re-injected then
covered with a DPC membrane, then dotted-and-dabbed, then tiled. *Now
OK.

--
(\__/) *
(='.'=)
(")_(")

That sounds like a very similar situation: The extension is at the
back of the kitchen to form a dining area - probably the next most
likely for condensation after a bathroom - and was formed of previous
outbuildings. From the look of things though, the walls were rebuilt
as the bricks are modern. Doing what you had to do sounds like a big
job but I suppose it's perfectly do-able given a bit of time, if it
makes a permanent solution.

On May 13, 10:35*am, "Nightjar \"cpb\"@" "insertmysurnamehere
wrote:
On 12/05/2011 18:25, GMM wrote:





I was looking at a house yesterday that had a clear problem with damp
getting into the plaster in a small extension (Victorian house but a
quite recent extension ie in the last few years). *The agent didn't
try to hide it (which would have been difficult!) but said it was
rising. *Now, the garden of this house falls away so at the point
where the damp was most apparent, the floor was about 10 courses of
bricks above ground level. *The wall was covered by a raised deck, so
I couldn't see whether it had a dpc, but could count approximately the
brick courses through the gaps between the boards. *I couldn't see any
obvious accumulation of soil/debris down there that would form a
bridge for damp to rise.
The worst of the damage to the plaster was just above skirting level,
so it looked like it could be rising and there was no obvious source
of a leak that would affect the one wall specifically.

So, the questions (!): *I thought I had read somewhere that damp could
only rise 3 - 4 feet in a wall. *Is this the case or am I mis-
remembering ? *(if there is a limit then it could be coming from
somewhere else).

Secondly, if it is rising damp, what's the best remedy? *I know
chemical dpcs are often mis-sold but are they effective or is there
another strategy that doesn't involve demolishing the whole thing and
starting again?

It goes without saying that a problem like this would be a good
justification for a low offer on the place, but I'd like to have some
feel for how low I have to make it to cover resolving the problem:
Apart from the damp and a couple of other small issues it's a good
place, which I might well buy.

Cheers chaps

A bit of reading that you might find useful:

http://www.safeguardeurope.com/pdf_d..._damp_book.pdf

Colin Bignell

That's interesting reading - Thanks Colin.