Hi All,

More damp questions - apologies for boring anyone.

The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before. Ground level is below both the
slate dpc and the silicon DPC. Room 25ft by 10ft.

Recently had a quote by a damp company (~£3K) to do the following;

- Inject DPC (already has a silicon one and a slate one)
- Strip plaster on two walls (total 35ft inc 3 windows and
frenchdoors)
- Treat the two walls with some sort of waterproofing "stuff"
- Replaster two walls
- Remove bottom 6" of external render and rerender with bellcast.
- Repoint two courses of bricks (35ft) below the DPC.

My plan is to get them to do the DPC (and wall treatment???) and I'll
do the rest. I appreciate the injected DPCs are not trusted by many
but I want to give this work every chance of fixing the problem.

For the internal walls;
- Should I plaster or use plasterboard with a skim? Damp Company
didn't like the idea of plasterboarding as it causes problem with the
wall treatment.
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.
- If I plasterboard it presumably celotex could be used to aid
insulation?
- Could I "dot 'n dab" plasterboard direct to the wall?
- Should I treat the bare brick in any way prior to this?
- Do I need to give the walls time to dry out?
- If so roughly how long?

For the external walls;
-What mix of render?
-Any tips with the bellcast beading? How far above the DPCs should it
be?
-What mix for repointing below the DPC?
-What mix for repointing above the DPC?

Incidentally, I am getting a few more quotes!!

All experiences/advice welcome...

Cheers,


Martin.

"Martin" wrote in message
om...
Hi All,

More damp questions - apologies for boring anyone.

The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before. Ground level is below both the
slate dpc and the silicon DPC. Room 25ft by 10ft.

Recently had a quote by a damp company (~£3K) to do the following;

- Inject DPC (already has a silicon one and a slate one)


If it has a slate DPC (which usually works or can be made to work) why does
it need an injected one (which doesn't) ?

"Martin" wrote in message
om...
Hi All,

More damp questions - apologies for boring anyone.

The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before. Ground level is below both the
slate dpc and the silicon DPC. Room 25ft by 10ft.

Recently had a quote by a damp company (~£3K) to do the following;

- Inject DPC (already has a silicon one and a slate one)
- Strip plaster on two walls (total 35ft inc 3 windows and
frenchdoors)
- Treat the two walls with some sort of waterproofing "stuff"
- Replaster two walls
- Remove bottom 6" of external render and rerender with bellcast.
- Repoint two courses of bricks (35ft) below the DPC.

My plan is to get them to do the DPC (and wall treatment???) and I'll
do the rest. I appreciate the injected DPCs are not trusted by many
but I want to give this work every chance of fixing the problem.

For the internal walls;
- Should I plaster or use plasterboard with a skim? Damp Company
didn't like the idea of plasterboarding as it causes problem with the
wall treatment.
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.
- If I plasterboard it presumably celotex could be used to aid
insulation?
- Could I "dot 'n dab" plasterboard direct to the wall?
- Should I treat the bare brick in any way prior to this?
- Do I need to give the walls time to dry out?
- If so roughly how long?

For the external walls;
-What mix of render?
-Any tips with the bellcast beading? How far above the DPCs should it
be?
-What mix for repointing below the DPC?
-What mix for repointing above the DPC?

Incidentally, I am getting a few more quotes!!

All experiences/advice welcome...

Cheers,


Martin.

am i right in believing that this is more or less floor to ceiling ?
I was always led to believe that rising damp gets about 2 foot up the wall
and hacking off to a metre high is the done thing.
I would suspect penetrating damp more than rising - are both walls exterior
and rendered ?

Regards Jeff

In article ,
(Martin) writes:
Hi All,

More damp questions - apologies for boring anyone.

The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is

By what means have you deduced it's not condensation?
Damp up near the ceiling is either condensation or penetrating damp.

evidence it's been a problem before. Ground level is below both the
slate dpc and the silicon DPC. Room 25ft by 10ft.

Recently had a quote by a damp company (~£3K) to do the following;

You have to accurately identify the cause of the damp before
thinking of ways to fix it. If you've done that, you haven't
said here, and it's necessary to know before advising how to
fix it and how to replaster afterwards.

My plan is to get them to do the DPC (and wall treatment???) and I'll
do the rest. I appreciate the injected DPCs are not trusted by many
but I want to give this work every chance of fixing the problem.

That starts by correctly identifying the cause.

--
Andrew Gabriel

In message , Martin
writes
The background - my living room has damp problems mainly on two walls -
it rises up to within a foot of the coving.

If your wall is damp above about 3ft, IT IS NOT RISING DAMP, and a DPC
has nothing to do with it.

1870s house solid walls. I've done all the usual checks. It's not
condensation and there is evidence it's been a problem before. Ground
level is below both the slate dpc and the silicon DPC. Room 25ft by
10ft.

Recently had a quote by a damp company (~£3K) to do the following;

- Inject DPC (already has a silicon one and a slate one) - Strip
plaster on two walls (total 35ft inc 3 windows and frenchdoors) -
Treat the two walls with some sort of waterproofing "stuff" - Replaster
two walls - Remove bottom 6" of external render and rerender with
bellcast. - Repoint two courses of bricks (35ft) below the DPC.

They obviously dont know what they are doing and are relying on your
ignorance to RIP YOU OFF!!!

The damp could be falling from within a foot of the coving, which
suggests that it is coming from above. It could be Gutters, Overflow
Pipe, Rotten Window, Shower/Sink/Bath/Central Heating etc. Leaking, and
so on - but it is not rising damp!!!

Unless your covings are only 4 ft from the floor/ground level.

--
Richard Faulkner

Martin wrote:
The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before.

Check your rendering. Check it again. Look for cracks, tap it to see
whether it sounds hollow. See if there are cracks around cills where
water could be getting in. Is the render painted? I've had a few
similar problems in the past.

Chris Bacon wrote:
Martin wrote:
The background - my living room has damp problems mainly on two
walls
- it rises up to within a foot of the coving. 1870s house solid
walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before.


The age of your house suggests that it has solid 9'' walls, was the
outside rendered to try to cure the problem ? does the damp worsen
after bad weather? old or blocked guttering may be overflowing on to
the wall side and getting behind the render, we had a simmilar problem
with water getting behind paint, once the paint was stripped away there
was a damp patch of about 8 square meters on the outside wall, its just
about dried out now ,about 7 months later

wrote in message roups.com...
Chris Bacon wrote:
Martin wrote:
The background - my living room has damp problems mainly on two
walls
- it rises up to within a foot of the coving. 1870s house solid
walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before.


The age of your house suggests that it has solid 9'' walls, was the
outside rendered to try to cure the problem ? does the damp worsen
after bad weather? old or blocked guttering may be overflowing on to
the wall side and getting behind the render, we had a simmilar problem
with water getting behind paint, once the paint was stripped away there
was a damp patch of about 8 square meters on the outside wall, its just
about dried out now ,about 7 months later

Hi All,

Good replies and questions as usual. Apologies for this long reply!

Contrary to one reply I don't regard myself as ignorant!!

Here is what has been tried.....(deep breath)

- Render is good. No cracks and painted. No knowing if it was applied
to try and cure the damp. The only problem I can see with the render
is that it has no bellcast on the bottom. I've no experience of
bellcasts but it makes sense to me.
-Gutter is good. Works with no blockages or leaks.
-No damp in the room immediately above the affected area. Recently
took it back to plaster and it was bone dry.
-The only source of water above the affected area are some central
heating pipes. I've had all the floorboards up and there is no
evidence of previous leaks or current leaks. It's all dusty dry.
-No water tanks or pipes in the loft.
-No water pipes in the walls.
-Damp has been a problem for some time. Replaced with double-glazing
approx one year ago. This has had no effect whatsoever. I've sealed it
up very throughly. No evidence of damp immediately around window when
I removed the old unit. Sash windows must have been fitted originally.
The gaps where the weight boxes would have been have been replced with
timber. These were bone dry and had no evidence of water damage.
-I've tried the old mirror trick and no condensate formed on the
mirror.
-When I replaced the window some of the least accesible brickwork was
noticeably damp.
-The metal inserts used to get a good corner on the plaster and a
couple of socket back boxes are rusting as well which indicates to me
that it's not condensation.
-I was told the same thing about rising damp being only able to get a
few feet up the wall but it doesn't change the fact I have damp to
approx 8ft.
-One builder and two damp companies have agreed the exterior render
(painted by the way) is in good order.
-Wall are solid 9" with no cavaties. It used to be a commercial
property but was converted to residential in 1988.
-Someone feel free to correct me, but I heard that slate dpcs fail
after a time. This one is 135+ years old so I'm not expecting it to be
that good.
-Both walls are exterior and rendered.
-Weather doesn't seem to affect the levels of damp - I experimented
over the summer.
-There is some paint bubbling on the outside when it rains (approx the
size of a dinner plate) but this approx 10ft from the worst affected
area. The rest of the paint seems to be stuck fast as is the render.

So the question remains (one I've been trying to answer for some time)
is it rising or penetrating damp. I see no way it could penetrate the
walls so it has to be rising damp? The only weird thing is it's almost
up to the ceiling.

I do have another couple of damp companies coming around to give me a
quote - it's going to be interesting to hear what they advise.

Any advice suggestions would be most appreciated. Someone did suggest
moving but that's not really possible at the moment!

Any experience of bellcasts on the render solving problems would be
good to hear. It does sound logical that rain hits the wall, runs down
and soaks in immediately above the silicon (and slate) dpc. A bellcast
would prevent this and theoretically involve only a small outlay of
time and expense to try.

Cheers,

Martin.

In message , Martin
writes
I do have another couple of damp companies coming around to give me a
quote - it's going to be interesting to hear what they advise.

Make sure that they are members of the BWPDA, (www.bwpda.co.uk).

Ask them how damp could rise above 3 ft, when all theory says it cant.

It may be worth paying for someone to take a core sample from the
brickwork to see if it is damp in the wall, and not just on the surface.

Many damp companies dont know what they are doing, and tell you
something needs doing when it doesnt.

Are you anywhere near Manchester?



--
Richard Faulkner

Martin wrote:
wrote in message
roups.com...
Chris Bacon wrote:
Martin wrote
-There is some paint bubbling on the outside when it rains (approx the
size of a dinner plate) but this approx 10ft from the worst affected
area. The rest of the paint seems to be stuck fast as is the render

Martin.

on our wall there were a few patches of bubbling paint the majority of
it looked fine, once removed though the wall was damp over a large area
which had been covered in 'good' paint. one of the problems was the
previous owners had used a rubber based paint half way up the wall (to
cure the damp) so the water couldn't evaporate once it had got behind
the paint, as someone said earlier any paint used should be breathable.
Could you scrape a patch of the bubbling paint away to see if the
render is damp underneath any water can travel a fair distance before
it finds its way in.

Hi Martin.


This is classic stuff, the damp old Victorian house that goes from bad
to worse despite all the efforts of dampproofing 'specialists'. And the
cause? The fact that all the wrong things are being done. This scenario
plays out over and over again, so often its a well known deal.

Add to this the twin facts that
a) you dont understand how damp is managed in Vic properties, and
b) you've made mistakes in your conlcusions,
and you cant get to the bottom of it either.

First, if you want to understand damp and Vic properties, I'd recommend
a good long chat at
http://www.periodproperty.co.uk/cgi-...rum2.pl?#43991


Now, whats going on:

1. Vic houses handled damp fine when they wre built, they were not pits
of damp. So the basic design is good.
2. Since its damp now, it is what has been changed that has caused it.

What has changed?

1. Airtight double glazing stops ventilation
2. Chimney blocked off
3. Maybe draught proofing elsewhere too
4. Gysum plaster and emulsion
5. Cement render and paint
6. shower installed

All of these increase the damp levels in the walls, and some properties
then begin to fail to deal satisfactorily with the damp.

Contrary to your conclusions, the cause is indeed condensation. Why did
the dehumidifier not cure it? Primarily because it has been going on
for so long that the walls have become soaked, so that it will take
many months to dry them out. Also there are other works that will need
doing to fix it properly, eg the exterior render will be an ongoing
problem.

What else needs doing?

The first thing to understand is you need to allow the wall to dry out,
not trap all that water in it, which is what all your presently
considered works are about.
No to tanking
No to rendering
No to painting with water resistant paints
No to a 3rd DPC (!!) (slate should last much longer than 130 years)

Yes to:
Humidistatic dehumidifier
Lowering ground levels if theyre at or above the dpc
Checking the drain channel drains properly
Repoint all failed mortar with lime - but dont remove anything thats
stuck hard.
Removing all exterior render, and finishing by either cleaning the
bricks up, or if theyre too much of a mess, lime render.
Remove interior plaster and replaster with lime, painting with lime
based paints, not emulsion.
Checking ground water drains away from the house, not to the walls.
And I would add ventilation to the house for your own health, though
this is not necessary re damp until such time as you stop using the
dehumidifier.

Pay attention to major sources of damp within the house:
Install dehumidifier in bathroom, or maybe a fan.
And possibly enclose the shower so it doesnt produce as much steam in
the room, if practical.
And preferably install a cooker hood


Understand some basic concepts with these houses:
1. More damp is produced inside by breathing, cooking and showering
than comes from outside
2. Thus what is wanted is porosity, to allow the damp out, quite the
opposite of sealing.
3. Damp proofing companies do work so they can get your money.
4. If dealt with appropriately, a Vic house with no dpc, no render, no
waterprofing treatments etc can be dry and healthy.
5. Also be aware that a 9" wall will take a very long time to dry out,
even with the above treatments done.


BTW there is one gotcha: the bricks will be very soft, and the cement
render hard, and it is _very_ easy to do serious brick damage when
removing the render. Proceeed only with serious care on this point.


NT

wrote:

Hi Martin.


This is classic stuff, the damp old Victorian house that goes from bad
to worse despite all the efforts of dampproofing 'specialists'. And the
cause? The fact that all the wrong things are being done. This scenario
plays out over and over again, so often its a well known deal.

Add to this the twin facts that
a) you dont understand how damp is managed in Vic properties, and
b) you've made mistakes in your conlcusions,
and you cant get to the bottom of it either.

First, if you want to understand damp and Vic properties, I'd recommend
a good long chat at
http://www.periodproperty.co.uk/cgi-...rum2.pl?#43991


Now, whats going on:

1. Vic houses handled damp fine when they wre built, they were not pits
of damp. So the basic design is good.
2. Since its damp now, it is what has been changed that has caused it.

What has changed?

1. Airtight double glazing stops ventilation
2. Chimney blocked off
3. Maybe draught proofing elsewhere too
4. Gysum plaster and emulsion
5. Cement render and paint
6. shower installed

All of these increase the damp levels in the walls, and some properties
then begin to fail to deal satisfactorily with the damp.

Contrary to your conclusions, the cause is indeed condensation. Why did
the dehumidifier not cure it? Primarily because it has been going on
for so long that the walls have become soaked, so that it will take
many months to dry them out. Also there are other works that will need
doing to fix it properly, eg the exterior render will be an ongoing
problem.

What else needs doing?

The first thing to understand is you need to allow the wall to dry out,
not trap all that water in it, which is what all your presently
considered works are about.
No to tanking
No to rendering
No to painting with water resistant paints
No to a 3rd DPC (!!) (slate should last much longer than 130 years)

Yes to:
Humidistatic dehumidifier
Lowering ground levels if theyre at or above the dpc
Checking the drain channel drains properly
Repoint all failed mortar with lime - but dont remove anything thats
stuck hard.
Removing all exterior render, and finishing by either cleaning the
bricks up, or if theyre too much of a mess, lime render.
Remove interior plaster and replaster with lime, painting with lime
based paints, not emulsion.
Checking ground water drains away from the house, not to the walls.
And I would add ventilation to the house for your own health, though
this is not necessary re damp until such time as you stop using the
dehumidifier.

Pay attention to major sources of damp within the house:
Install dehumidifier in bathroom, or maybe a fan.
And possibly enclose the shower so it doesnt produce as much steam in
the room, if practical.
And preferably install a cooker hood


Understand some basic concepts with these houses:
1. More damp is produced inside by breathing, cooking and showering
than comes from outside
2. Thus what is wanted is porosity, to allow the damp out, quite the
opposite of sealing.
3. Damp proofing companies do work so they can get your money.
4. If dealt with appropriately, a Vic house with no dpc, no render, no
waterprofing treatments etc can be dry and healthy.
5. Also be aware that a 9" wall will take a very long time to dry out,
even with the above treatments done.


BTW there is one gotcha: the bricks will be very soft, and the cement
render hard, and it is _very_ easy to do serious brick damage when
removing the render. Proceeed only with serious care on this point.


NT

I'd agree with that. It's the conclusion I came to, despite all the advice I
was given by "experts" when I was considering buying a damp Victorian house
a couple of years ago.

There are some additions. Make sure the tumble drier is properly vented and
the filter is clear. Don't dry washing in the house. Open the windows wide
and let the wind blow through the house once a week in addition to normal
good ventilation.

I also think similar things apply to much more recent buildings. I've
experienced these problems in '60s flats and a '50s bungalow. Efforts to
keep rain and weather out cause troublesome build up of condensation. Once
the condensation has built up in the structure it has every appearance of
coming in from outside. It takes months to dry out.

Don't paint outside walls unless it is absolutely necessary, and then use a
paint that won't prevent the wall to dry outwards.

(I'm trying to dry out the insulation in an old freezer at the moment - and
it is taking weeks. Think how much longer a wall will take.)

And don't forget there's little money to be made from giving "ventilate -
don't cause moisture buildup" kind of advice.

Edgar

This is classic stuff, the damp old Victorian house that goes from bad
to worse despite all the efforts of dampproofing 'specialists'. And the
cause? The fact that all the wrong things are being done. This scenario
plays out over and over again, so often its a well known deal.

Add to this the twin facts that
a) you dont understand how damp is managed in Vic properties, and
b) you've made mistakes in your conlcusions,
and you cant get to the bottom of it either.

First, if you want to understand damp and Vic properties, I'd recommend
a good long chat at
http://www.periodproperty.co.uk/cgi-...rum2.pl?#43991


Now, whats going on:

1. Vic houses handled damp fine when they wre built, they were not pits
of damp. So the basic design is good.
2. Since its damp now, it is what has been changed that has caused it.

What has changed?

1. Airtight double glazing stops ventilation
2. Chimney blocked off
3. Maybe draught proofing elsewhere too
4. Gysum plaster and emulsion
5. Cement render and paint
6. shower installed

All of these increase the damp levels in the walls, and some properties
then begin to fail to deal satisfactorily with the damp.

Contrary to your conclusions, the cause is indeed condensation. Why did
the dehumidifier not cure it? Primarily because it has been going on
for so long that the walls have become soaked, so that it will take
many months to dry them out. Also there are other works that will need
doing to fix it properly, eg the exterior render will be an ongoing
problem.

What else needs doing?

The first thing to understand is you need to allow the wall to dry out,
not trap all that water in it, which is what all your presently
considered works are about.
No to tanking
No to rendering
No to painting with water resistant paints
No to a 3rd DPC (!!) (slate should last much longer than 130 years)

Yes to:
Humidistatic dehumidifier
Lowering ground levels if theyre at or above the dpc
Checking the drain channel drains properly
Repoint all failed mortar with lime - but dont remove anything thats
stuck hard.
Removing all exterior render, and finishing by either cleaning the
bricks up, or if theyre too much of a mess, lime render.
Remove interior plaster and replaster with lime, painting with lime
based paints, not emulsion.
Checking ground water drains away from the house, not to the walls.
And I would add ventilation to the house for your own health, though
this is not necessary re damp until such time as you stop using the
dehumidifier.

Pay attention to major sources of damp within the house:
Install dehumidifier in bathroom, or maybe a fan.
And possibly enclose the shower so it doesnt produce as much steam in
the room, if practical.
And preferably install a cooker hood


Understand some basic concepts with these houses:
1. More damp is produced inside by breathing, cooking and showering
than comes from outside
2. Thus what is wanted is porosity, to allow the damp out, quite the
opposite of sealing.
3. Damp proofing companies do work so they can get your money.
4. If dealt with appropriately, a Vic house with no dpc, no render, no
waterprofing treatments etc can be dry and healthy.
5. Also be aware that a 9" wall will take a very long time to dry out,
even with the above treatments done.


BTW there is one gotcha: the bricks will be very soft, and the cement
render hard, and it is _very_ easy to do serious brick damage when
removing the render. Proceeed only with serious care on this point.

The oracle has spoken!
Your condensation theory is blown away when you consider that most of
these
houses get the same symptoms after a heavy shower in mid summer, when
there
are insufficient cold surfaces to cause condensation, and the windows are
wide open.
The idea that a house should allow the passage of any amount of water
through the walls and wait for it to dry out is Dickensian, and faintly
ridiculous in this day and age. It means houses would effectively be damp
for at least 9 months of the year.
What has changed to make Victorian properties leak like a sieve, when
presumably they didn't originally, is IMO the degradation of the lime
mortar. If that powder between the bricks in a 9" wall is all that's
protecting you from the elements, then you need look no further. Replacing
it with mud would be an improvement.

On 5 Apr 2005 12:59:30 -0700, (Martin) wrote:

Hi All,

More damp questions - apologies for boring anyone.

The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before. Ground level is below both the
slate dpc and the silicon DPC. Room 25ft by 10ft.

Recently had a quote by a damp company (~£3K) to do the following;

- Inject DPC (already has a silicon one and a slate one)
- Strip plaster on two walls (total 35ft inc 3 windows and
frenchdoors)
- Treat the two walls with some sort of waterproofing "stuff"
- Replaster two walls
- Remove bottom 6" of external render and rerender with bellcast.
- Repoint two courses of bricks (35ft) below the DPC.

My plan is to get them to do the DPC (and wall treatment???) and I'll
do the rest. I appreciate the injected DPCs are not trusted by many
but I want to give this work every chance of fixing the problem.

For the internal walls;
- Should I plaster or use plasterboard with a skim? Damp Company
didn't like the idea of plasterboarding as it causes problem with the
wall treatment.
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.
- If I plasterboard it presumably celotex could be used to aid
insulation?
- Could I "dot 'n dab" plasterboard direct to the wall?
- Should I treat the bare brick in any way prior to this?
- Do I need to give the walls time to dry out?
- If so roughly how long?

For the external walls;
-What mix of render?
-Any tips with the bellcast beading? How far above the DPCs should it
be?
-What mix for repointing below the DPC?
-What mix for repointing above the DPC?

Incidentally, I am getting a few more quotes!!

All experiences/advice welcome...

Hi,

A few q's, what sort of % humidity do you get inside at room
temperatures? Is the render bridging the DPC? Is the render made from
a breathable mortar, and is it painted? What sort of windows and
heating is there? Did the damp company suggest taking samples from the
wall and having them analysed for salts?

Why not put in a dehumidifier with a humidistat to gain some time
while you investigate the whole thing more fully? Just about
everything you need to know is in the archives of this group and the
forums at 'Period Property'

Bear in mind in the old days the fireplace and draughty windows would
keep the place nice and dry.

cheers,
Pete.

In article ,
Martin wrote:
More damp questions - apologies for boring anyone.

The background - my living room has damp problems mainly on two walls
- it rises up to within a foot of the coving. 1870s house solid walls.
I've done all the usual checks. It's not condensation and there is
evidence it's been a problem before. Ground level is below both the
slate dpc and the silicon DPC. Room 25ft by 10ft.

I assume this is a brick built house? If so, the very first thing to do is
to check the pointing. And not just visually - for a long way round the
effected area 'tap' it to see if it's loose. And I'll bet you'll find
problems. Rake out and replace using a lime mortar. Don't be tempted to
use a more common sand and cement mix - this will simply crack due to
movement.

Of course, also check for things like failed gutters allowing the wall to
get soaked.

Also, on an old house built in this way, if you've removed and sealed up
all the fireplaces, and fitted double glazing, without adequate
ventilation, and don't keep it warm, you'll get condensation.

--
*I am a nobody, and nobody is perfect; therefore I am perfect*

Dave Plowman London SW
To e-mail, change noise into sound.

Martin wrote:
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.

Don't use gypsum plaster on anything that's likely to get damp,
incidentally. It will not last.

Chris Bacon wrote in message ...
Martin wrote:
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.

Don't use gypsum plaster on anything that's likely to get damp,
incidentally. It will not last.

Check pointing
Is the floor dirt - my 1850s semi had carpet on tiles on sand/earth.
so even though outside ground level was below the dpc the walls were
still damp - this construction is ok but it's not designed to have
carpet etc. on it, only bare tiles so that moisture can evaporate.

Check ventilation of chimney etc. - are you drying washing inside?

Has the house been unoccupied?

I put in a small French drain - dug down about 9-12" on outside walls,
and about 9" away from walls, and filled the trench with pea shingle,
and put old slate floor tiles as a border - looks good.

Whilst doing the French drain I also repaired the pointing
underground, which was very bad around the bay window (lots of
movement that made cracks and the lime mortar had fallen out), and
cleaned all the caked on clay from the bricks (which may assist the
wicking-up of water into the walls).

Can't defiantely say but I think the French drain did quite a lot - it
now means that damp wpould have to travel up an extra 12" before it
gets inside.

I also replaced the floor with an insulated dpc protected concrete
floor - diy it and it's quite cheap, and a good workout.

There is a side which says that rising damp is not a real problem and
damp companies do nothing and are a waste of time. If you want to go
down this route you can rent the solutions and pumps, drills etc.
quite cheaply and do the whole thing in a weekend for about £100-150
(if you do this do rent/buy a good SDS drill and have a spare 10 mm
bit).

I'd try the simple things first pointing (above and below ground),
French drain, ventilation, put heating on, open a window when drying
washing etc.

Good luck

(nafuk) wrote in message . com...
Chris Bacon wrote in message ...
Martin wrote:
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.

Don't use gypsum plaster on anything that's likely to get damp,
incidentally. It will not last.

Check pointing
Is the floor dirt - my 1850s semi had carpet on tiles on sand/earth.
so even though outside ground level was below the dpc the walls were
still damp - this construction is ok but it's not designed to have
carpet etc. on it, only bare tiles so that moisture can evaporate.

Check ventilation of chimney etc. - are you drying washing inside?

Has the house been unoccupied?

I put in a small French drain - dug down about 9-12" on outside walls,
and about 9" away from walls, and filled the trench with pea shingle,
and put old slate floor tiles as a border - looks good.

Whilst doing the French drain I also repaired the pointing
underground, which was very bad around the bay window (lots of
movement that made cracks and the lime mortar had fallen out), and
cleaned all the caked on clay from the bricks (which may assist the
wicking-up of water into the walls).

Can't defiantely say but I think the French drain did quite a lot - it
now means that damp wpould have to travel up an extra 12" before it
gets inside.

I also replaced the floor with an insulated dpc protected concrete
floor - diy it and it's quite cheap, and a good workout.

There is a side which says that rising damp is not a real problem and
damp companies do nothing and are a waste of time. If you want to go
down this route you can rent the solutions and pumps, drills etc.
quite cheaply and do the whole thing in a weekend for about £100-150
(if you do this do rent/buy a good SDS drill and have a spare 10 mm
bit).

I'd try the simple things first pointing (above and below ground),
French drain, ventilation, put heating on, open a window when drying
washing etc.

Good luck


Hi All,

Apologies for the lack of reply. Computer packed up but at least that
was cheap DIY fix!!

Affected wall is painted and rendered. Below the silicon injections,
the render does need repair. Still don't know if it's rising damp or
penetrating damp.

Floor is good with the correct membrane.

There is also a draining channel against the wall - half full of
shingle.

At the moment, I'm getting quite cheesed off with this damp problem.
Another company have just paid me a visit. Their recommendation is to
tank the walls at a cost of £4k+.

Now I'm really unsure of what to do. £4K+ seems *cough* excessive. DIY
tanking?? The company's attitude was that on damp solid walls only
tanking would fix it. So I assume he believes it's penetrating damp.
However, he then went on about the temperature difference being
greater which implies condensation so why should it need tanking?
Hmmm...

A few answers to previous questions...

Q: Is the house occupied?
A: Yep. For 15+ years

Q: Are the gutters ok?
A: Perfect. No leaks, no overflowing. They work fine.

Q: Old house now sealed up causing condensation?
A: Condensation is definetly not the issue. I ran a dehumidifer for 6
months+ and it made no difference. Plaster was still coming off the
wall.

Q: What sort of % humidity?
A: No idea. Dehumidifer was running and walls were still damp. I don't
do anything daft liking drying washing in the house.

Q: Check ventilation?
A: No obvious ventilation but dehumidifer made no diffence. Solid
floor, no air bricks, no vents, no chimney. Strange for a house that
used to be a Bakery but I've found no evidence of where a chimney used
to be.

Any other suggestions? DIY tanking?
I've another company paying me a visit on Monday - anyone care to take
bets on their being a third different solution to the same problem?


Cheers,

Martin.

Any other suggestions? DIY tanking?
I've another company paying me a visit on Monday - anyone care to
take
bets on their being a third different solution to the same problem?


The best advice i received when we had our problems was from a painter
and decorator, it was a medium sized company, the Boss came round,no
reps, he said he sees it all the time, what did impress me was he didnt
view it as a 'problem' it was just his job

wrote in message roups.com...
Any other suggestions? DIY tanking?
I've another company paying me a visit on Monday - anyone care to
take
bets on their being a third different solution to the same problem?


The best advice i received when we had our problems was from a painter
and decorator, it was a medium sized company, the Boss came round,no
reps, he said he sees it all the time, what did impress me was he didnt
view it as a 'problem' it was just his job


As other posters are saying, this just doesn't sound like rising damp.

However if you do decide to chase the rising damp idea, avoid wet
injection pressurised damp proof injection systems. These work by
injecting a water diluted silicone (or similar chemical) into the wall
& then you have to wait for the old water PLUS the new water to dry
out before you (might) have a dry wall.

A better alternative is Dryzone Cream made by Safeguard Chemicals of
Horsham. It changes the chemical nature of the mortar bewteen the
bricks rendering it waterproof & there is no new water going into the
wall. You still have to drill 12mm holes into the wall every 100mm,
as in the wet systems, but you drill into the mortar which is easier.
Then you squeeze the cream into the holes by a special applicator gun
- low pressure, no messy spills.

(Martin) wrote in message om...
(nafuk) wrote in message . com...
Chris Bacon wrote in message ...
Martin wrote:
- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.

Don't use gypsum plaster on anything that's likely to get damp,
incidentally. It will not last.

Check pointing
Is the floor dirt - my 1850s semi had carpet on tiles on sand/earth.
so even though outside ground level was below the dpc the walls were
still damp - this construction is ok but it's not designed to have
carpet etc. on it, only bare tiles so that moisture can evaporate.

Check ventilation of chimney etc. - are you drying washing inside?

Has the house been unoccupied?

I put in a small French drain - dug down about 9-12" on outside walls,
and about 9" away from walls, and filled the trench with pea shingle,
and put old slate floor tiles as a border - looks good.

Whilst doing the French drain I also repaired the pointing
underground, which was very bad around the bay window (lots of
movement that made cracks and the lime mortar had fallen out), and
cleaned all the caked on clay from the bricks (which may assist the
wicking-up of water into the walls).

Can't defiantely say but I think the French drain did quite a lot - it
now means that damp wpould have to travel up an extra 12" before it
gets inside.

I also replaced the floor with an insulated dpc protected concrete
floor - diy it and it's quite cheap, and a good workout.

There is a side which says that rising damp is not a real problem and
damp companies do nothing and are a waste of time. If you want to go
down this route you can rent the solutions and pumps, drills etc.

quite cheaply and do the whole thing in a weekend for about £100-150
(if you do this do rent/buy a good SDS drill and have a spare 10 mm
bit).

I'd try the simple things first pointing (above and below ground),
French drain, ventilation, put heating on, open a window when drying
washing etc.

Good luck


Hi All,

Apologies for the lack of reply. Computer packed up but at least that
was cheap DIY fix!!

Affected wall is painted and rendered. Below the silicon injections,
the render does need repair. Still don't know if it's rising damp or
penetrating damp.

Floor is good with the correct membrane.

There is also a draining channel against the wall - half full of
shingle.

At the moment, I'm getting quite cheesed off with this damp problem.
Another company have just paid me a visit. Their recommendation is to
tank the walls at a cost of £4k+.

Now I'm really unsure of what to do. £4K+ seems *cough* excessive. DIY
tanking?? The company's attitude was that on damp solid walls only
tanking would fix it. So I assume he believes it's penetrating damp.
However, he then went on about the temperature difference being
greater which implies condensation so why should it need tanking?
Hmmm...

A few answers to previous questions...

Q: Is the house occupied?
A: Yep. For 15+ years

Q: Are the gutters ok?
A: Perfect. No leaks, no overflowing. They work fine.

Q: Old house now sealed up causing condensation?
A: Condensation is definetly not the issue. I ran a dehumidifer for 6
months+ and it made no difference. Plaster was still coming off the
wall.

Q: What sort of % humidity?
A: No idea. Dehumidifer was running and walls were still damp. I don't
do anything daft liking drying washing in the house.

Q: Check ventilation?
A: No obvious ventilation but dehumidifer made no diffence. Solid
floor, no air bricks, no vents, no chimney. Strange for a house that
used to be a Bakery but I've found no evidence of where a chimney used
to be.

Any other suggestions? DIY tanking?
I've another company paying me a visit on Monday - anyone care to take
bets on their being a third different solution to the same problem?


Cheers,

Martin.

If the outside finish is waterproof (as opposed to water-repellant)
then your walls can't dry from the outside. All they will eternally do
is soak up moisture from the inside air by condensation, particularly
if they are single thickness and always colder than the inside. How
about stripping any waterproofing from the outside and relacing it
with breathable water-repellant.
M.K.

On 9 Apr 2005 07:57:05 -0700, (markzoom) wrote:

Like others I've had success with French drains. You could also make
the inside of the wall breathable so the damp can evaporate into the
room. Of course there is a limit to how much water can evaporate and
if you have a stream erupting onto the wall, breathability is not
going to help, though a French drain would

Breathability - remove gypsum plaster, cement render and modern paints
from the inside of the ?bricks?. Do not add any tanking, PVA etc.
Replaster with lime plaster and paint with limewash. It can't do any
harm, is cheap if you do it yourself and might do a lot of good

Anna


~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plaster repairs
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
|____| www.kettlenet.co.uk 01359 230642

markzoom wrote:

(Martin) wrote in message om...

(nafuk) wrote in message . com...

Chris Bacon wrote in message ...

Martin wrote:

- If I plaster, what type(s) of plaster should I use? I would get
someone in to do this.

Don't use gypsum plaster on anything that's likely to get damp,
incidentally. It will not last.

Check pointing
Is the floor dirt - my 1850s semi had carpet on tiles on sand/earth.
so even though outside ground level was below the dpc the walls were
still damp - this construction is ok but it's not designed to have
carpet etc. on it, only bare tiles so that moisture can evaporate.

Check ventilation of chimney etc. - are you drying washing inside?

Has the house been unoccupied?

I put in a small French drain - dug down about 9-12" on outside walls,
and about 9" away from walls, and filled the trench with pea shingle,
and put old slate floor tiles as a border - looks good.

Whilst doing the French drain I also repaired the pointing
underground, which was very bad around the bay window (lots of
movement that made cracks and the lime mortar had fallen out), and
cleaned all the caked on clay from the bricks (which may assist the
wicking-up of water into the walls).

Can't defiantely say but I think the French drain did quite a lot - it
now means that damp wpould have to travel up an extra 12" before it
gets inside.

I also replaced the floor with an insulated dpc protected concrete
floor - diy it and it's quite cheap, and a good workout.

There is a side which says that rising damp is not a real problem and
damp companies do nothing and are a waste of time. If you want to go
down this route you can rent the solutions and pumps, drills etc.


quite cheaply and do the whole thing in a weekend for about £100-150
(if you do this do rent/buy a good SDS drill and have a spare 10 mm
bit).

I'd try the simple things first pointing (above and below ground),
French drain, ventilation, put heating on, open a window when drying
washing etc.

Good luck


Hi All,

Apologies for the lack of reply. Computer packed up but at least that
was cheap DIY fix!!

Affected wall is painted and rendered. Below the silicon injections,
the render does need repair. Still don't know if it's rising damp or
penetrating damp.

Floor is good with the correct membrane.

There is also a draining channel against the wall - half full of
shingle.

At the moment, I'm getting quite cheesed off with this damp problem.
Another company have just paid me a visit. Their recommendation is to
tank the walls at a cost of £4k+.

Now I'm really unsure of what to do. £4K+ seems *cough* excessive. DIY
tanking?? The company's attitude was that on damp solid walls only
tanking would fix it. So I assume he believes it's penetrating damp.
However, he then went on about the temperature difference being
greater which implies condensation so why should it need tanking?
Hmmm...

A few answers to previous questions...

Q: Is the house occupied?
A: Yep. For 15+ years

Q: Are the gutters ok?
A: Perfect. No leaks, no overflowing. They work fine.

Q: Old house now sealed up causing condensation?
A: Condensation is definetly not the issue. I ran a dehumidifer for 6
months+ and it made no difference. Plaster was still coming off the
wall.

Q: What sort of % humidity?
A: No idea. Dehumidifer was running and walls were still damp. I don't
do anything daft liking drying washing in the house.

Q: Check ventilation?
A: No obvious ventilation but dehumidifer made no diffence. Solid
floor, no air bricks, no vents, no chimney. Strange for a house that
used to be a Bakery but I've found no evidence of where a chimney used
to be.

Any other suggestions? DIY tanking?
I've another company paying me a visit on Monday - anyone care to take
bets on their being a third different solution to the same problem?


Cheers,

Martin.


If the outside finish is waterproof (as opposed to water-repellant)
then your walls can't dry from the outside. All they will eternally do
is soak up moisture from the inside air by condensation, particularly
if they are single thickness and always colder than the inside. How
about stripping any waterproofing from the outside and relacing it
with breathable water-repellant.
M.K.

Ho w about opening a ****ing wibdow or fitting stautory ventilation?


Since is is now mnadatory that hoese have vapour bariers inside them,
yoyr explanbatuoj is ********.

Martin wrote :-

Affected wall is painted and rendered. Below the silicon injections,
the render does need repair. Still don't know if it's rising damp or
penetrating damp.

If the render extends below the dampproof membrane then it is bridging the
membrane - it needs removing to above the membrane

chemical injection is one thing but you also have to take care of the
obvious ie make sure nothing can bridge the new DPC outside or inside - I
had to remove render outside and have 7" skirting inside


There is also a draining channel against the wall - half full of
shingle.

What exactly is this ?

Regards Jeff

On 9 Apr 2005 02:18:01 -0700, (Martin) wrote:

A few answers to previous questions...

Q: Old house now sealed up causing condensation?
A: Condensation is definetly not the issue. I ran a dehumidifer for 6
months+ and it made no difference. Plaster was still coming off the
wall.

Q: What sort of % humidity?
A: No idea. Dehumidifer was running and walls were still damp. I don't
do anything daft liking drying washing in the house.

Hi,

What sort of heating arrangements do you have? Eg how long is the room
heated per day and to what temperature.

Also what sort of windows do you have? Eg double glazed or draughty
sash etc

And does the render bridge the slate DPC in any way?

A dehumidifier won't necessarily remove the damp under any
circumstances but it should at least contain the problem to some
extent while it's investigated.

Any other suggestions? DIY tanking?
I've another company paying me a visit on Monday - anyone care to take
bets on their being a third different solution to the same problem?

AFAIK one of the best ways of diagnosing damp is to send samples of
the wall away for chemical analysis for hygroscopic salts.

Dry lining the wall might be another way forward.

cheers,
Pete.

"Martin" wrote in message
m...
Affected wall is painted and rendered. Below the silicon injections,
the render does need repair. Still don't know if it's rising damp or
penetrating damp.

Floor is good with the correct membrane.

There is also a draining channel against the wall - half full of
shingle.

So which side of the membrane is this ?

Also how old is the house ? Should there be a membrane at all ? In very
old houses in a damp location you need the whole floor area to evaporate the
moisture. It may be this membrane is pushing all the damp into the walls
until they are saturated amd things start to fail.



At the moment, I'm getting quite cheesed off with this damp problem.

Where are you ?


Another company have just paid me a visit. Their recommendation is to
tank the walls at a cost of £4k+.

Unless it's underground and you've no other way of removing the water I
wouldn't.

If the outside is already rendered and painted, I'd try a pliolite based
solvent masonry paint. Johnstones do a a product called Stormguard, and
most
trade paint companies have equivalent brands. These are *vastly* superior
to
normal masonry paints and aren't that expensive. That should at least
eliminate penetrating damp as the cause.
Stone sills are also a major source of damp, however sound they look.
Water
often sits in puddles, and has time to soak into the brickwork and travel
through the mortar.
In a brick built house rising damp is probably the least likely source.


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