A 30 ft length of my ground floor walls are damp, up to 4ft above
ground in the interior of the house. Some builders have advised me
that the walls have been plastered with the wrong type of plaster, but
logic tells me that if there was no damp in the walls, it wouldn't
matter what kind of plaster was used.

The red brick house was built in 1900 with cavity walls and lime
mortar. I dare say the cavities have probably got more debris in them
than they should have, and it may well come up above the level of the
slate DPC.

I've lived with this problem since I moved in, 15 years ago, thanks to
painting with damp-block paint. But I want to sell the house soon, and
would like to get the problem cured prior to selling - provided it can
be done without the sort of disruption that replastering the walls
would create.

When I looked into this a few years ago, the most popular treatments
seemed to be silicone injection and the osmosis method. I never did
ascertain if either was actually considered effective by folks who
have actually tried them. Perhaps there are other, more effective
methods nowadays.

Any info or opinions based on first-hand experience would be much
appreciated.

TIA

Drake

Drake wrote:

A 30 ft length of my ground floor walls are damp, up to 4ft above
ground in the interior of the house. Some builders have advised me
that the walls have been plastered with the wrong type of plaster, but
logic tells me that if there was no damp in the walls, it wouldn't
matter what kind of plaster was used.

The red brick house was built in 1900 with cavity walls and lime
mortar. I dare say the cavities have probably got more debris in them
than they should have, and it may well come up above the level of the
slate DPC.

I've lived with this problem since I moved in, 15 years ago, thanks to
painting with damp-block paint. But I want to sell the house soon, and
would like to get the problem cured prior to selling - provided it can
be done without the sort of disruption that replastering the walls
would create.

When I looked into this a few years ago, the most popular treatments
seemed to be silicone injection and the osmosis method. I never did
ascertain if either was actually considered effective by folks who
have actually tried them. Perhaps there are other, more effective
methods nowadays.

Any info or opinions based on first-hand experience would be much
appreciated.

TIA

Drake

Sounds like youve been sold the usual damp treatment sales line. There
is no instant damp cure, as whatever the cause it takes a while for
walls to dry out. The quickest and cheapest is a dehumidifier, which
can cure your condensation almost overnight. Rising damp has nothing to
do with it, but its a long story.


NT

On 14 Sep 2006 05:17:10 -0700, wrote:


Sounds like youve been sold the usual damp treatment sales line. There
is no instant damp cure, as whatever the cause it takes a while for
walls to dry out.

I didn't say I was looking for an instant cure.

The quickest and cheapest is a dehumidifier, which
can cure your condensation almost overnight.

I don't have condensation - just rising damp.

Drake

Drake wrote:
A 30 ft length of my ground floor walls are damp, up to 4ft above
ground in the interior of the house. Some builders have advised me
that the walls have been plastered with the wrong type of plaster, but
logic tells me that if there was no damp in the walls, it wouldn't
matter what kind of plaster was used.

If they have been plastered with browning, then it does make a difference,
especially if they have bridged the DPC when plastering, the browning will
suck up the water like a sponge and hold it for months, meaning that it will
never dry out.


The red brick house was built in 1900 with cavity walls and lime
mortar. I dare say the cavities have probably got more debris in them
than they should have, and it may well come up above the level of the
slate DPC.


Highly likely


I've lived with this problem since I moved in, 15 years ago, thanks to
painting with damp-block paint. But I want to sell the house soon, and
would like to get the problem cured prior to selling - provided it can
be done without the sort of disruption that replastering the walls
would create.


It's a bit strange this (fairly new) idea of getting things right just to
sell the house...you've put up with damp for 15 years and now someone else
is moving in you want to get it sorted out.
:-p


When I looked into this a few years ago, the most popular treatments
seemed to be silicone injection and the osmosis method. I never did
ascertain if either was actually considered effective by folks who
have actually tried them. Perhaps there are other, more effective
methods nowadays.

Any info or opinions based on first-hand experience would be much
appreciated.

There is no easy cure...you have limited options:

1) ignore it and sell your house for a few thousand less than it's market
value
2) try to hide it and fail, then go back to number 1!
3) get it sorted out once and for all, this involves taking off the plaster
up to 1 metre high and having it chemically treated with DP liquid or gel,
leaving the brickwork for a month or more to dry (by dehumidifier) before
having it rendered with waterproofing agents and finally top coat plaster
and reinstating skirtings and decor.

Personally, I'd go for option 1 if I were you, the few thousand they will
knock off the price will be the same as you will pay to get it done
properly, but you won't have to put up with the disruption.

I've seen the osmosis method used many times, I've never spoken to anyone
who noticed it working though

On Thu, 14 Sep 2006 19:44:57 GMT, "Phil L"
wrote:

Drake wrote:
A 30 ft length of my ground floor walls are damp, up to 4ft above
ground in the interior of the house. Some builders have advised me
that the walls have been plastered with the wrong type of plaster, but
logic tells me that if there was no damp in the walls, it wouldn't
matter what kind of plaster was used.

If they have been plastered with browning, then it does make a difference,
especially if they have bridged the DPC when plastering, the browning will
suck up the water like a sponge and hold it for months, meaning that it will
never dry out.


The red brick house was built in 1900 with cavity walls and lime
mortar. I dare say the cavities have probably got more debris in them
than they should have, and it may well come up above the level of the
slate DPC.


Highly likely


I've lived with this problem since I moved in, 15 years ago, thanks to
painting with damp-block paint. But I want to sell the house soon, and
would like to get the problem cured prior to selling - provided it can
be done without the sort of disruption that replastering the walls
would create.


It's a bit strange this (fairly new) idea of getting things right just to
sell the house...you've put up with damp for 15 years and now someone else
is moving in you want to get it sorted out.
:-p

Hi Phil,
Thank you for the input. My reasoning is that while *I* know that the
rising damp is not a very serious issue (having lived with it for 15
years, insulated from it by the damp-block paint). But I suspect that
a good proportion of buyers out there avoid houses with rising damp
like the plague (even if offered at a few k discount), possibly
because of a widespread impression people have that it is incurable.

1) ignore it and sell your house for a few thousand less than it's market
value
[some lines snipped for concision]
Personally, I'd go for option 1 if I were you, the few thousand they will
knock off the price will be the same as you will pay to get it done
properly, but you won't have to put up with the disruption.

Yes, that option certainly holds some appeal. But I could imagine that
rising damp could knock at least £10k off a house's value, whereas
getting it properly treated would prolly cost £1k at most...

Drake

Drake wrote:

I don't have condensation - just rising damp.

This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.

If you still think its rising damp, just sell, for 2 reasons. First
youre unlikely to get it sorted. Second the buyer will only knock off
the dpc & replaster cost, whereas if you do it you'll have redecoration
as well.


NT

wrote:
Drake wrote:

I don't have condensation - just rising damp.

This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.

Why we've bothered with dpcs all these years I can't imagine


If you still think its rising damp, just sell, for 2 reasons. First
youre unlikely to get it sorted. Second the buyer will only knock off
the dpc & replaster cost, whereas if you do it you'll have redecoration
as well.


NT

On 15 Sep 2006 10:08:46 -0700, wrote:

Drake wrote:

I don't have condensation - just rising damp.

This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.

Really? Which scientific articles and experiments?

If you place a dry house brick in 1" of water, it will certainly
absorb some of the water, and the dampness will rise above water
level. Why would a whole wall built of bricks and lime mortar behave
any differently?

If you still think its rising damp,

just sell, for 2 reasons. First
youre unlikely to get it sorted. Second the buyer will only knock off
the dpc & replaster cost, whereas if you do it you'll have redecoration
as well.

You may be right about that.

Cheers,

Drake

Drake wrote:
On 15 Sep 2006 10:08:46 -0700, wrote:
Drake wrote:

I don't have condensation - just rising damp.

This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.

Really? Which scientific articles and experiments?

One of thesee days I'll get round to putting a list together. Until
then its a case of google. Look for experimental walls in water for a
start, and many other things. There are many writings about the
subject.
http://www.periodproperty.co.uk/discussion_forum.htm
has a lot of discussion about damp and rising damp, but you'd need to
do a lot of reading to find it all.


If you place a dry house brick in 1" of water, it will certainly
absorb some of the water, and the dampness will rise above water
level.

yes, but not far.

Why would a whole wall built of bricks and lime mortar behave
any differently?

It doesnt, it behaves the same, water rises a few inches only. Its been
done.

The usual endpoint is that people cant be bothered to read up on it.


NT

wrote:
Drake wrote:

I don't have condensation - just rising damp.

This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.


Tht is total ********. Otherwise why have a DPC in the first place?

I've had it in three properties.

If you have a brick wall in contact with wet ground you get rising damp,
period.


If you still think its rising damp, just sell, for 2 reasons. First
youre unlikely to get it sorted. Second the buyer will only knock off
the dpc & replaster cost, whereas if you do it you'll have redecoration
as well.


You can tackle it one of two ways.

Get a DPC under the wall, and if bridged clear the bridging.

Put internal tanking up the inside, so that by the time the damp rises
beyond it, enough of it has evaporated outwards.

The worst thing you can do is confuse it with penetrating damp, and put
a waterproof layer outside.





NT

The message
from The Natural Philosopher contains these words:

If you have a brick wall in contact with wet ground you get rising damp,
period.

We had a house in Hounslow that had no DPC (it was built in 1853) and
the ground under the floorboards was wet. We had no trouble with damp
apart from the overall dampness of having wet soil under the
floorboards. The walls were fine.

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from The Natural Philosopher contains these words:

If you have a brick wall in contact with wet ground you get rising damp,
period.

We had a house in Hounslow that had no DPC (it was built in 1853) and
the ground under the floorboards was wet. We had no trouble with damp
apart from the overall dampness of having wet soil under the
floorboards. The walls were fine.


It may well have had engineering bricks or a slate course.

The key is outward evaporation, ind possible inward as well.

i.e. the one place where I had a real problem in one house was behind
kitchen units. No way to get the moisture OUT.. and of course
condensation contributed..

Tanking it up with mortar before putting new units in sorted it
completely - the wall HAD to dry OUTWARDS.

I will note that unless you have a really porous structure, or a sealed
in one, rising damp seldom rises beyond a couple of feet max. The rate
of evaporation from the outside is high enough to limit it. My worst
was an un DPC-able chimney sitting in an underfloor puddle, in the house
center. - that rose up to about 2 ft. Any wood in contact had rotted away.

In article ,
The Natural Philosopher writes:
My worst
was an un DPC-able chimney sitting in an underfloor puddle, in the house
center. - that rose up to about 2 ft. Any wood in contact had rotted away.

Chimney's often have inadequate damp proofing because they relied
on regular use to keep them dry. In my 1909 house, the brickwork
does have a slate DPC which still works, but hearths are constructed
with a retaining wall (with DPC) which is then infilled with whatever
building rubble and soil was to hand (with no DPC). This wicked up
moisture and destroyed the wall plates sitting on the retaining walls
once the fireplaces ceased being used (one of the joists I sucked up
with the vacuum cleaner;-)

In one room, I emptied out the rubble, and replaced the hearth with
a suspended floor right across the top, with a new hearth built on
top of the floor, since it had to be raised above floor level in
order to fit a coal-effect gas fire. In the other room, I emptied
out the rubble down to the DPC in the brickwork, put in a DP membrane,
and rebuilt the floor with a layer of vermaculite insulation under a
very thick layer of sand and cement, so it could be used with an open
grate in the future (not that I intend to). Both have remained dry
ever since.

--
Andrew Gabriel

Drake wrote:
On 15 Sep 2006 10:08:46 -0700, wrote:

Drake wrote:

I don't have condensation - just rising damp.
This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.

Really? Which scientific articles and experiments?

Just the one probably, the BRE experiment, which you can no doubt
purchase from their bookshop if you have more money than sense.


If you place a dry house brick in 1" of water, it will certainly
absorb some of the water, and the dampness will rise above water
level. Why would a whole wall built of bricks and lime mortar behave
any differently?

If you still think its rising damp,

just sell, for 2 reasons. First
youre unlikely to get it sorted. Second the buyer will only knock off
the dpc & replaster cost, whereas if you do it you'll have redecoration
as well.

You may be right about that.

Cheers,

Drake

wrote:
Drake wrote:
On 15 Sep 2006 10:08:46 -0700, wrote:
Drake wrote:

I don't have condensation - just rising damp.

This is why you dont know how to solve it. If you can be bothered to
read the scientific experiments and articles on rising damp you'll find
its all but non existant.

Really? Which scientific articles and experiments?

One of thesee days I'll get round to putting a list together.

I don't think you'll find enough to form a list but, in any event, maybe
you should do that before pontificating on the subject.

Until
then its a case of google. Look for experimental walls in water for a
start, and many other things. There are many writings about the
subject.
http://www.periodproperty.co.uk/discussion_forum.htm
has a lot of discussion about damp and rising damp, but you'd need to
do a lot of reading to find it all.


If you place a dry house brick in 1" of water, it will certainly
absorb some of the water, and the dampness will rise above water
level.

yes, but not far.

Why would a whole wall built of bricks and lime mortar behave
any differently?

It doesnt, it behaves the same, water rises a few inches only. Its been
done.

The usual endpoint is that people cant be bothered to read up on it.


NT