I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Knocking off the damp plaster throughout to about 1 to 1.3m reveals
that the bricks have been injected at some point in the past. I wasn't
sure what else needed done, so Rentokil sent along a surveyor today to
have a look. He drilled a hole in a wall, put the dust in a flask type
thing and showed me that it was 10% (apparently 4% or above is a
problem).

He's suggested 2 things;
1. Injecting the mortar just above floor level throughout, cost £1200
(exc VAT)
2. Getting Rentokil to plaster as well, with 'special' plaster that
will repel the water still in the damp bricks, cost about £3000 (exc.
VAT)

He says that if I put normal plaster on the walls without letting them
dry out, the new plaster will crack and fall off. A little research
suggests two alternatives to rather expensive Rentokil plastering;

1. Cover walls with PVA and then apply plaster with 'waterproofing'
mixed in (what is this waterproofing bit?)
2. Cover walls with cement render, which I'm told is waterproof, with
added benefit of adding support to slightly dodgy brickwork.

Does anyone have any advice for me on these points? It is probably
clear that my building knowledge is limited, so please assume I know
very little if you reply!! Whilst the house is a building site it
would be great to get this all sorted, and not have to worry about it
in the future.

Thanks in advance for any assistance, Ellen

In message , Ellen
Rawlinson writes
I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Knocking off the damp plaster throughout to about 1 to 1.3m reveals
that the bricks have been injected at some point in the past. I wasn't
sure what else needed done, so Rentokil sent along a surveyor today to
have a look. He drilled a hole in a wall, put the dust in a flask type
thing and showed me that it was 10% (apparently 4% or above is a
problem).

He's suggested 2 things;
1. Injecting the mortar just above floor level throughout, cost £1200
(exc VAT)
2. Getting Rentokil to plaster as well, with 'special' plaster that
will repel the water still in the damp bricks, cost about £3000 (exc.
VAT)

He says that if I put normal plaster on the walls without letting them
dry out, the new plaster will crack and fall off. A little research
suggests two alternatives to rather expensive Rentokil plastering;

1. Cover walls with PVA and then apply plaster with 'waterproofing'
mixed in (what is this waterproofing bit?)
2. Cover walls with cement render, which I'm told is waterproof, with
added benefit of adding support to slightly dodgy brickwork.

Does anyone have any advice for me on these points? It is probably
clear that my building knowledge is limited, so please assume I know
very little if you reply!! Whilst the house is a building site it
would be great to get this all sorted, and not have to worry about it
in the future.

Thanks in advance for any assistance, Ellen

Get comparable reports and quotes from 2 or 3 members of the BWPDA

http://www.bwpda.co.uk

Rentokill are a big brand name and almost certainly charge accordingly.

--
Richard Faulkner

On 27 Oct 2004 06:34:13 -0700, (Ellen
Rawlinson) wrote:

I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Knocking off the damp plaster throughout to about 1 to 1.3m reveals
that the bricks have been injected at some point in the past. I wasn't
sure what else needed done, so Rentokil sent along a surveyor today to
have a look. He drilled a hole in a wall, put the dust in a flask type
thing and showed me that it was 10% (apparently 4% or above is a
problem).

He's suggested 2 things;
1. Injecting the mortar just above floor level throughout, cost £1200
(exc VAT)
2. Getting Rentokil to plaster as well, with 'special' plaster that
will repel the water still in the damp bricks, cost about £3000 (exc.
VAT)

He says that if I put normal plaster on the walls without letting them
dry out, the new plaster will crack and fall off. A little research
suggests two alternatives to rather expensive Rentokil plastering;

1. Cover walls with PVA and then apply plaster with 'waterproofing'
mixed in (what is this waterproofing bit?)
2. Cover walls with cement render, which I'm told is waterproof, with
added benefit of adding support to slightly dodgy brickwork.

Does anyone have any advice for me on these points? It is probably
clear that my building knowledge is limited, so please assume I know
very little if you reply!! Whilst the house is a building site it
would be great to get this all sorted, and not have to worry about it
in the future.

Thanks in advance for any assistance, Ellen

My architect has a big problem with these injection solutions, He says
it takes 10 years for the damp to rise 1m in a wall, so if you hack
off 1m of plaster, and replace with waterproof plaster, you need do
noting else, to achieive a 10 year solution.

There are tanking membrans that you can fit under plaster, I will fit
these to the walls in my house that have no DPC.

Cement render really needs a waterproofer, its only waterproof if its
made really strong, and then it srinks as it sets ..... There are many
available.

There are some electronic systems, I looked into one, but when I told
the sales guy building regs wanted to see the BBA cert for it, he ran
a mile.

I suspect you need a guy who knows his stuff to vist your place,
rather than a guy trained for 3 days in a classroom.

Rick

He says that if I put normal plaster on the walls without letting them
dry out, the new plaster will crack and fall off.

Let the walls dry out naturally. You've probably already fixed the problem
and don't need to spend thousands on solutions that may not be necessary.

If you can't wait to plaster, consider using a lime plaster, which will
breathe naturally. In the meantime, keep the property well heated and
consider buying/renting a dehumdifier to speed up the process.

Alternatively, if the internals of the house have no particular historic
significance, such as original cornicing or plaster detailing, then consider
drylining instead of wet plastering, using celotex/kingspan. This will
dramatically increase the comfort and energy efficiency of the house and
none of the damp will get past the insulant and vapour barrier to ruin the
attached plasterboard/paper. Even 10mm of insulation would make a
significant difference, whilst 25mm would be good and 50mm excellent. If
you've knocked off the bonding plaster, than a 25mm total thickness of
insulation and plasterboard isn't that much thicker than wet plastering.

Christian.

On 27 Oct 2004 06:34:13 -0700, (Ellen
Rawlinson) wrote:

I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Congratulations. Now the sensible thing to do is ignore the problem
until next Summer. We've had a wet Autumn and it's going to get worse.
Assuming that your guess is exactly right (and I bet it was), then
your house will remain damp for quite some time - nothing short of
freeze-drying it is going to remove the existing moisture, so you're
just going to have to wait a while to really find out what's what.

No-one with a shiny suit and a magic meter knows _anything_ more than
this. You know the walls _were_ wet, you now have to hope you've
removed the single cause and that drying out will improve things.
"Tests" won't tell you any more about causes than simple visual
inspection.

In the meantime, assume the worst. Don't hang valuable pictures on
outside walls. Put some $5 hygrometers around the place. Think about a
dehumidifier. Don't redecorate yet, and expect to do so next year.

Knocking off the damp plaster throughout to about 1 to 1.3m

That's even more than I would have done so far.

Rentokil sent along a surveyor today

Never mind. I'm sure there's a pest control company that can
eradicate it. Just keep the food in sealed tins and don't let them
build a nest.


Rentokil are not a trustworthy company for damp proofing (Look what
happened over their past guarantees). "Surveyors" that work for
solution companies are implicitly untrustworthy. You've very probably
fixed the real problem of the exterior bridging and internal
injections et al. are a very poor second best in comparison.


BTW - What happened about the original buyer's surey and spotting the
bridging in the first place ?

--
Smert' spamionam

I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Sounds good. Sit tight until after next summer to give everything a
good chance to dry out, but I can imagine you don't want rough brick
walls for that long so ...

I wouldn't use anything waterproof. Waterproof means that water can't
get through it, but the water doesn't magically vanish, it just goes
somewhere else which can easily be into the plaster which is a couple
of meters up your wall so you are just moving the problem elsewhere

I'd plaster with lime plaster instead of sand&cement render or gypsum
plaster. In a 100 year old house your original plaster will be lime
plaster - it only went out of fashion after the last war. Lime plaster
doesn't fail when it gets wet, in fact it is breatheable (which
neither sand/cement render or gypsum are) which means that gradually
moisture will escape through it. If you use lime plaster then don't
paint your walls with modern plastic paints or use vinyl wallpaper
which will trap the moisture again - at least not until everything has
dried out well

The problem you are likely to have is finding a plasterer who is
willing to use lime plaster (they don't get taught that in college
these days) so you might end up DIYing it You can try asking your
local council conservation department for names of lime plasterers

Shout if you want any more advice

Anna



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

(Ellen Rawlinson) wrote in message . com...
I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Knocking off the damp plaster throughout to about 1 to 1.3m reveals
that the bricks have been injected at some point in the past. I wasn't
sure what else needed done, so Rentokil sent along a surveyor today to
have a look. He drilled a hole in a wall, put the dust in a flask type
thing and showed me that it was 10% (apparently 4% or above is a
problem).

He's suggested 2 things;
1. Injecting the mortar just above floor level throughout, cost £1200
(exc VAT)
2. Getting Rentokil to plaster as well, with 'special' plaster that
will repel the water still in the damp bricks, cost about £3000 (exc.
VAT)

He says that if I put normal plaster on the walls without letting them
dry out, the new plaster will crack and fall off. A little research
suggests two alternatives to rather expensive Rentokil plastering;

1. Cover walls with PVA and then apply plaster with 'waterproofing'
mixed in (what is this waterproofing bit?)
2. Cover walls with cement render, which I'm told is waterproof, with
added benefit of adding support to slightly dodgy brickwork.

Does anyone have any advice for me on these points? It is probably
clear that my building knowledge is limited, so please assume I know
very little if you reply!! Whilst the house is a building site it
would be great to get this all sorted, and not have to worry about it
in the future.

Thanks in advance for any assistance, Ellen

ugh, youre barking right up the wrong tree. Dont even go there. The
experts are here, you need to understand the important concepts:

http://www.periodproperty.co.uk/cgi-...sing/forum2.pl

dont do whats youre suggesting.

NT

Ellen Rawlinson wrote:

He's suggested 2 things;
1. Injecting the mortar just above floor level throughout, cost £1200
(exc VAT)

Pointless (for you, at any rate)


2. Getting Rentokil to plaster as well, with 'special' plaster that
will repel the water still in the damp bricks, cost about £3000 (exc.
VAT)

Ditto.



He says that if I put normal plaster on the walls without letting them
dry out, the new plaster will crack and fall off. A little research
suggests two alternatives to rather expensive Rentokil plastering;

1. Cover walls with PVA and then apply plaster with 'waterproofing'
mixed in (what is this waterproofing bit?)
2. Cover walls with cement render, which I'm told is waterproof, with
added benefit of adding support to slightly dodgy brickwork.

Does anyone have any advice for me on these points? It is probably
clear that my building knowledge is limited, so please assume I know
very little if you reply!! Whilst the house is a building site it
would be great to get this all sorted, and not have to worry about it
in the future.

1. Fix whatever drainage exists around the outside.
2. Adequately ventilate.
3. Adequately heat.
4. Replaster.

Our 1930s house has no dpc and no dpm. It was very damp when we moved in
3 years ago. Very, very damp. Following the above steps (all advice from
this group BTW) has completely removed the damp.


--
Grunff

Having dealt with half a dozen similar problems over the years, I would say
the simple solution is to use a pva modified mortar to bond Aquapanels to
the inside brickwork.
If the outside is being painted, use a solvent based pliolite masonry paint,
which is genuinely water resistant but still gives a matt finish.
As to walls breathing, lime mortar, and other mud hut technology, I'd say
that nothing stops the passage of air through mortar. Okay, walls have to
breathe, but you need to stop them drinking.

Grunff wrote in message ...
Ellen Rawlinson wrote:

2. Getting Rentokil to plaster as well, with 'special' plaster that
will repel the water still in the damp bricks, cost about £3000 (exc.
VAT)

Ditto.

I dont think theres even any such a thing

"Anna Kettle" wrote in message
...
I'd plaster with lime plaster instead of sand&cement render or gypsum
plaster. In a 100 year old house your original plaster will be lime
plaster - it only went out of fashion after the last war. Lime plaster

I like the idea of lime - but is it strong enough to put screws in? I have
memories of old houses with light fittings, bannisters etc dangling where
rawlplugs have turned what should have been a nice 6mm hole into a dusty,
almost conical excavation.

Is there some special technique for fixing shelves, heavy mirrors etc to a
lime plastered wall (without drilling through in the hope of finding a lump
of stone and using 6" frame fixings to reach it!)?

Around here it it so difficult to get anyone who says they will come and
plaster to actually come and do "your" job that one daren't frighten them
off with talk of lime...

Roger Moss

"stuart noble" wrote in message ...
Having dealt with half a dozen similar problems over the years, I would say
the simple solution is to use a pva modified mortar to bond Aquapanels to
the inside brickwork.
If the outside is being painted, use a solvent based pliolite masonry paint,
which is genuinely water resistant but still gives a matt finish.
As to walls breathing, lime mortar, and other mud hut technology, I'd say
that nothing stops the passage of air through mortar. Okay, walls have to
breathe, but you need to stop them drinking.

Thank you very much for the advice. At the risk of looking a fool,
could I ask what aquapanels are?!

Ellen

Andy Dingley wrote in message . ..
On 27 Oct 2004 06:34:13 -0700, (Ellen
Rawlinson) wrote:

I have just bought a very wet house! Semi detached about 100 years
old. I've taken some steps to try and cure what I thought the cause of
the problem was i.e. removing the 12 inches of concrete that encased
the building above the internal floor levels, fixing drains, removing
3 feet of concrete render along one side, gutters etc. It subjectively
feels much drier even after only 4 weeks.

Congratulations. Now the sensible thing to do is ignore the problem
until next Summer. We've had a wet Autumn and it's going to get worse.
Assuming that your guess is exactly right (and I bet it was), then
your house will remain damp for quite some time - nothing short of
freeze-drying it is going to remove the existing moisture, so you're
just going to have to wait a while to really find out what's what.

No-one with a shiny suit and a magic meter knows _anything_ more than
this. You know the walls _were_ wet, you now have to hope you've
removed the single cause and that drying out will improve things.
"Tests" won't tell you any more about causes than simple visual
inspection.

In the meantime, assume the worst. Don't hang valuable pictures on
outside walls. Put some $5 hygrometers around the place. Think about a
dehumidifier. Don't redecorate yet, and expect to do so next year.

Knocking off the damp plaster throughout to about 1 to 1.3m

That's even more than I would have done so far.

Rentokil sent along a surveyor today

Never mind. I'm sure there's a pest control company that can
eradicate it. Just keep the food in sealed tins and don't let them
build a nest.


Rentokil are not a trustworthy company for damp proofing (Look what
happened over their past guarantees). "Surveyors" that work for
solution companies are implicitly untrustworthy. You've very probably
fixed the real problem of the exterior bridging and internal
injections et al. are a very poor second best in comparison.


BTW - What happened about the original buyer's surey and spotting the
bridging in the first place ?

I bought it knowing full well it was very damp. I got a full
structural survey from a very helpful, friendly and talkative
surveyor, and this, along with detailed inspection, suggested doing
the things I've already done would go at least part way to solving the
problem. I just wasn't sure if I still needed things like injections
or mechanical DPC etc as well.... unfortunately getting Rentokil out
didn't really help!!!

In article ,
Ellen Rawlinson wrote:
He's suggested 2 things; 1. Injecting the mortar just above floor level
throughout, cost £1200 (exc VAT) 2. Getting Rentokil to plaster as well,
with 'special' plaster that will repel the water still in the damp
bricks, cost about £3000 (exc. VAT)

Both these treatments used to be a near essential when obtaining a
mortgage some years ago on any similar aged house. Like mine. As part of a
damp/woodwork warranty that the BS insisted on. And the first few
companies I tried insisted mine needed it (using their measuring
instruments) and it was the only way.

But the house has beautiful high Victorian skirting boards, and I didn't
want to lose them.

Eventually, I found a company which would fix the wood rot - there was
some - and supply the required warranty. Without installing either a 'damp
course' or re-plastering.

30 or so years on, I dunno if I have damp or not. Nothing goes mouldy, and
wallpaper stays on the walls. Of course the house is now well heated and
ventilated.

--
*Pentium wise, pen and paper foolish *

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

In article ,
stuart noble wrote:
Having dealt with half a dozen similar problems over the years, I would
say the simple solution is to use a pva modified mortar to bond
Aquapanels to the inside brickwork.

Is this on your own property, or being paid to do it for others?

If the outside is being painted, use a solvent based pliolite masonry
paint, which is genuinely water resistant but still gives a matt finish.

Why would you paint bricks?

As to walls breathing, lime mortar, and other mud hut technology, I'd say
that nothing stops the passage of air through mortar.

If you mean lime mortar, that's the reason for using it. If you mean
mortar in general, surely waterproof ones are available?


Okay, walls have to
breathe, but you need to stop them drinking.

Perhaps it didn't rain 100 years ago?

--
*Stable Relationships Are For Horses.

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

On 28 Oct 2004 08:06:15 -0700, (Ellen
Rawlinson) wrote:

At the risk of looking a fool,
could I ask what aquapanels are?!

The same things I asked about just a couple of days ago. 8-)

They're a bit like MDF, except made with cement instead of woodglue.
So you have a very heavy, dark grey piece of "board" that doesn't mind
getting wet. Popular for making shower enclosures, because you can
tile over the top.

A few years back I made a Gaudi-like tiled garden pond from this stuff
- Aquapanel, bought from Wickes. This week I'm replacing exterior
fascia boards with another brand, Viroc Versapanel. Following
recommendations though, I'm having the plywood shop saw it to size for
me, to save dust and wear on my tools.

I also have a suspicion that 20 years ago this stuff was radically
new, and I bought a pair of hand-made speaker enclosures made from it.
"Musician Bonsais", individually made drive units by a lab technician
(?) at Liverpool University. And very good they still are ! It's an
excellent material for making speakers - even better than MDF.
--
Smert' spamionam

On Thu, 28 Oct 2004 16:59:36 +0100, "Dave Plowman (News)"
wrote:

But the house has beautiful high Victorian skirting boards, and I didn't
want to lose them.

It's just timber and some time on the spindle moulder. You can have
them any made shape or size you want, and it'll still be cheaper than
B&Q,

In article ,
Andy Dingley wrote:
But the house has beautiful high Victorian skirting boards, and I didn't
want to lose them.

It's just timber and some time on the spindle moulder. You can have
them any made shape or size you want, and it'll still be cheaper than
B&Q,

Was even cheaper not to have the rooms re-plastered.

--
*Why is the time of day with the slowest traffic called rush hour?

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

"Roger Moss" wrote in message
...

"Anna Kettle" wrote in message
...
I'd plaster with lime plaster instead of sand&cement render or gypsum
plaster. In a 100 year old house your original plaster will be lime
plaster - it only went out of fashion after the last war. Lime plaster

I like the idea of lime - but is it strong enough to put screws in? I
have
memories of old houses with light fittings, bannisters etc dangling where
rawlplugs have turned what should have been a nice 6mm hole into a dusty,
almost conical excavation.

Is there some special technique for fixing shelves, heavy mirrors etc to a
lime plastered wall (without drilling through in the hope of finding a
lump
of stone and using 6" frame fixings to reach it!)?

I don't really think gypsum is strong enough to support these things either.

"Ellen Rawlinson" wrote
| Rentokil sent along a surveyor today

That is a *salesman* not a surveyor.

| to have a look. He drilled a hole in a wall, put the dust in
| a flask type thing and showed me that it was 10% (apparently 4%
| or above is a problem).

Nah, it's only a problem if it feels squelchy when you prod it.

Others have outlined the solution.

Owain

On Thu, 28 Oct 2004 12:39:05 +0100, "Roger Moss"
wrote:

I like the idea of lime - but is it strong enough to put screws in?

No, you fix battens to the
timber/brick/stone/SomethingThatIsStrongEnough and then hang things
off the battens

I have memories of old houses with light fittings, bannisters etc
dangling where rawlplugs have turned what should have been a nice
6mm hole into a dusty, almost conical excavation.

Typical DIY'ers!

Is there some special technique for fixing shelves, heavy mirrors etc
to a lime plastered wall (without drilling through in the hope of
finding a lump of stone and using 6" frame fixings to reach it!)?

We don't have stone here in sunny Suffolk so I'm not at all up on this
one. If you don't get a reply here then your best bet is to ask on
http://www.periodproperty.co.uk/

Around here it it so difficult to get anyone who says they will come
and plaster to actually come and do "your" job that one daren't frighten
them off with talk of lime...

Pity cos when they have to use it they end up being very enthusiastic.
Its nice stuff to use. Maybe you should offer to send a likely
plasterer on a one day 'Lime plastering for plasterers' course. There
is bound to be one near you sometime

Anna

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

In article ,
Roger Moss wrote:
I like the idea of lime - but is it strong enough to put screws in?

No plaster is strong enough for fixings. You go through that into the
brick behind.

I have memories of old houses with light fittings, bannisters etc
dangling where rawlplugs have turned what should have been a nice 6mm
hole into a dusty, almost conical excavation.

Old houses didn't use rawlplugs - they're too recent an invention. The
common way to fix to a brick wall was to hammer wood wedges between bricks
and fix to them. If those do come loose, you're left with a pretty large
hole. With a light fitting to lath and plaster ceiling, the correct way is
to fit a batten between the joists, and fix to that.

What you're describing is not a problem with the material, but a lack of
decent workmanship.

--
*Failure is not an option. It's bundled with your software.

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

Dave Plowman (News) wrote in message ...
In article ,
stuart noble wrote:
Having dealt with half a dozen similar problems over the years, I would
say the simple solution is to use a pva modified mortar to bond
Aquapanels to the inside brickwork.
Is this on your own property, or being paid to do it for others?

The latter, although on the understanding at the time that it was
"experimental". I didn't see why you couldn't use resin bonded cement boards
(Aquapanel) as a kind of waterproof plasterboard, and they appear to have
worked 5+ years down the line. I think similar materials are probably used
to clad the exterior of modern office buildings.

If the outside is being painted, use a solvent based pliolite masonry
paint, which is genuinely water resistant but still gives a matt finish.

Why would you paint bricks?

Either because they were previously painted, or rendered. If not, I'd
re-point to 1" depth and hope the bricks themselves weren't too porous. IME
the mortar is always the weak link.

As to walls breathing, lime mortar, and other mud hut technology, I'd say
that nothing stops the passage of air through mortar.

If you mean lime mortar, that's the reason for using it. If you mean
mortar in general, surely waterproof ones are available?

But they still allow air through, together with any moisture it may be
carrying. Only a plastic membrane makes things genuinely waterproof.

Okay, walls have to
breathe, but you need to stop them drinking.

Perhaps it didn't rain 100 years ago?

Dampness was accepted, along with a lot of other inconveniences that we
don't put up with today.
I accept that lime mortar is still doing its job in many ancient buildings.
What I dispute is that it was ever a good material for bricklaying.

In article ,
"stuart noble" writes:

Either because they were previously painted, or rendered. If not, I'd
re-point to 1" depth and hope the bricks themselves weren't too porous. IME

That's too deep. Repointing is putting on a new exposed
surface, not rebuilding a wall whilst it's standing
(which it might not be if you rake out too much).
Normally, 1/4" is the amount it's safe to rake out.

--
Andrew Gabriel

In article ,
stuart noble wrote:
Okay, walls have to
breathe, but you need to stop them drinking.

Perhaps it didn't rain 100 years ago?

Dampness was accepted, along with a lot of other inconveniences that we
don't put up with today.

I don't think so. Wallpaper was common much before this, and it will soon
fall off in damp conditions - then as now.

Houses heated by open fires are by nature well ventilated. Remove the
ventilation and all sorts of problems occur.

Your treatment attempts to deal with 'rising' damp. The general view these
days is that *genuine* rising damp is actually rare, and that most who
recommend treatment for similar symptoms - even if they do exist - are
more likely to be profit motivated.

--
*I started out with nothing, and I still have most of it.

Dave Plowman London SW
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On Fri, 29 Oct 2004 10:36:28 +0100, "Dave Plowman (News)"
wrote:

Old houses didn't use rawlplugs - they're too recent an invention.

Rawlplugs go back to the '20s, AFAIK.
Of course, those were the fibrous ones.

In article ,
Andy Dingley wrote:
Old houses didn't use rawlplugs - they're too recent an invention.

Rawlplugs go back to the '20s, AFAIK.
Of course, those were the fibrous ones.

Yup. However, I'm not sure how long it took for them to come into general
use on new builds. I've worked on '30s houses with the 'wedge between
bricks' method.

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Dave Plowman London SW
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Dave Plowman (News) wrote in message ...
Your treatment attempts to deal with 'rising' damp.
Does it?
The general view these
days is that *genuine* rising damp is actually rare, and that most who
recommend treatment for similar symptoms - even if they do exist - are
more likely to be profit motivated.
I've never believed in it in brick built houses and, if it does exist, it's
likely to be combined with penetrating damp. Fact is I don't really care
where it's coming from. The wall is damp and you want to stop that
penetrating to the inside so you put a barrier there which prevents water
coming in but allows water vapour to escape. Easy to do, no drying time, and
leaves you a good finish to decorate.

Grunff wrote in message ...

1. Fix whatever drainage exists around the outside.
2. Adequately ventilate.
3. Adequately heat.
4. Replaster.

Our 1930s house has no dpc and no dpm. It was very damp when we moved in
3 years ago. Very, very damp. Following the above steps (all advice from
this group BTW) has completely removed the damp.

Grunff

Could you please expand a bit on what adequately ventilating and
adequately heating actually involved i.e. what the situation was when
you started and what changes you made ?

Thanks

In article , Dave Plowman (News)
wrote:
Yup. However, I'm not sure how long it took for them
[Rawlplugs] to come into general use on new builds.

Google scores again - first invented c.1919

"Tuesday, January 30, 2001 :

Rawlplug, which makes wall-fixings, was today snapped up by plaster
and plasterboard supplier BPB for £27m. ...

The 82-year old plug was invented by builder John Rawlings and is
used after drilling to fix anything from shelving to pictures to
walls.

It was originally made out of jute, bonded with animal blood, but
was replaced with plastic in the 1960s."

http://archives.tcm.ie/breakingnews/.../story2926.asp

I'm of an age to remember the Rawlplug tool: a sort of masonry
drill in a metal handle that you hammered and rotated to make the
hole. No wonder they had to have big mental asylums in those days!

--
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In article ,
Tony Bryer writes:

I'm of an age to remember the Rawlplug tool: a sort of masonry
drill in a metal handle that you hammered and rotated to make the
hole. No wonder they had to have big mental asylums in those days!

I still have several, although they belong to my father.
He used them to install central heating around 1960, so
they are for 1/2", 3/4", and 1 1/4" pipe holes.

I used an SDS drill to install mine, although I used them
a number of times before I bought an SDS drill.

--
Andrew Gabriel

In article ,
Tony Bryer wrote:
I'm of an age to remember the Rawlplug tool: a sort of masonry
drill in a metal handle that you hammered and rotated to make the
hole. No wonder they had to have big mental asylums in those days!

I've still got a couple. But the big local asylum is now houses.;-)

They were actually quite quick into normal brick etc once you got the hang.
And would also work - but slowly - into much harder materials. Only the
advent of the SDS drill finally put mine to bed. A hammer drill and
masonry bit couldn't do everything a Rawltool could.

--
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Dave Plowman London SW
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Andrew Gabriel wrote in message ...
In article ,
"stuart noble" writes:

Either because they were previously painted, or rendered. If not, I'd
re-point to 1" depth and hope the bricks themselves weren't too porous.
IME

That's too deep. Repointing is putting on a new exposed
surface, not rebuilding a wall whilst it's standing
(which it might not be if you rake out too much).
Normally, 1/4" is the amount it's safe to rake out.

On most of the walls I've worked on round here you can rake out 1" with your
finger, and 1/4" of mortar perched on top of something that unstable would
be purely cosmetic. The entire front of my 1900 lime mortar brick built
house was done to an inch with cement/pva mortar 10+ years ago (up to 4"
deep in places where the Victorian bodgers must have run out of mud). Since
then, no cracks, no spalling and, more important, no damp.
I should also mention that the original mortar here was heavily dosed with
brick dust, the poor man's pozzolan. It seems to me that if you make lime
set in this way, you're going to lose the self-healing properties attributed
to it. Can't have it both ways I guess.

TRK's dad wrote:

Could you please expand a bit on what adequately ventilating and
adequately heating actually involved i.e. what the situation was when
you started and what changes you made ?

Sure!

Heating:
No CH, some electric heaters and two open fires. Replaced with CH, UFH
in kitchen and one wood burner.


Ventilation:
Many of the room vents were blocled up. We cleared those, so there are 2
vents on the ground floor and two on the first floor.


Water ingress:
Guttering was replaced, and outside render patched.


The house was really very, very damp when we moved in. I suspect the
heating and fixing the gutters were the most important fixes.

--
Grunff

In article ,
stuart noble wrote:
Your treatment attempts to deal with 'rising' damp.

Does it?

Well, it was given as an alternative to a mortar skim plus replaster of
the bottom metre or so, so I took it it was? Or are you recommending
replacing the plaster on *all* outside walls with this method?

The general view these days is that *genuine* rising damp is actually
rare, and that most who recommend treatment for similar symptoms - even
if they do exist - are more likely to be profit motivated.

I've never believed in it in brick built houses and, if it does exist,
it's likely to be combined with penetrating damp. Fact is I don't really
care where it's coming from. The wall is damp and you want to stop that
penetrating to the inside so you put a barrier there which prevents
water coming in but allows water vapour to escape. Easy to do, no drying
time, and leaves you a good finish to decorate.

Assuming the original plaster is ok, it's simply adding considerable cost.

If you've cured the cause of penetrating damp by removing piled up soil
etc and made sure the pointing is sound - as you'd have to do anyway -
leaving things to dry out naturally in a habited house would be my advice.

--
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Dave Plowman London SW
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In article ,
stuart noble wrote:
On most of the walls I've worked on round here you can rake out 1" with
your finger, and 1/4" of mortar perched on top of something that
unstable would be purely cosmetic.

In some ways, it only is. It certainly shouldn't be structural in the
cases of shallow footings where there is bound to be some movement. It's
only to form a waterproof seal.

--
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Dave Plowman London SW
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"Andy Dingley" wrote in message
...
On Fri, 29 Oct 2004 10:36:28 +0100, "Dave Plowman (News)"
wrote:

Old houses didn't use rawlplugs - they're too recent an invention.

Rawlplugs go back to the '20s, AFAIK.
Of course, those were the fibrous ones.


I`ve got a newspaper that I found under our floorboards from 1911 - it`s got
a fantastic full front page advert for Rawlplugs.

"4 Tons Held By One Number 25 Rawlplug!" sort of stuff with line drawings of
lathes swinging from hooks. Pity the poor sod that had to drill out that
hole with his hammer and rawlbit.


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"stuart noble" wrote in message ...
Dave Plowman (News) wrote in message ...
In article ,
stuart noble wrote:

Having dealt with half a dozen similar problems over the years, I would
say the simple solution is to use a pva modified mortar to bond
Aquapanels to the inside brickwork.
Is this on your own property, or being paid to do it for others?

The latter, although on the understanding at the time that it was
"experimental". I didn't see why you couldn't use resin bonded cement boards
(Aquapanel) as a kind of waterproof plasterboard, and they appear to have
worked 5+ years down the line. I think similar materials are probably used
to clad the exterior of modern office buildings.

If the outside is being painted, use a solvent based pliolite masonry
paint, which is genuinely water resistant but still gives a matt finish.

Why would you paint bricks?

Either because they were previously painted, or rendered. If not, I'd
re-point to 1" depth and hope the bricks themselves weren't too porous. IME
the mortar is always the weak link.

As to walls breathing, lime mortar, and other mud hut technology, I'd say
that nothing stops the passage of air through mortar.

If you mean lime mortar, that's the reason for using it. If you mean
mortar in general, surely waterproof ones are available?

But they still allow air through, together with any moisture it may be
carrying. Only a plastic membrane makes things genuinely waterproof.

Okay, walls have to
breathe, but you need to stop them drinking.

Perhaps it didn't rain 100 years ago?

Dampness was accepted, along with a lot of other inconveniences that we
don't put up with today.
I accept that lime mortar is still doing its job in many ancient buildings.
What I dispute is that it was ever a good material for bricklaying.


I'm sorry to say you show complete failure to understand how damp
control worked in 1800s buildings. Vic buildings rarely need dpcs,
injections, tanking etc to make them fnuction healthily again. The
vast majority of the damp problems with Vic houses are due to
1. attempting to treat them like more modern types of construction,
when they approach damp control in a completely different way, and
2. failure to maintain satisfactorily.


Tanking the walls with aquapanel and painting the exterior are about
the last things that will help a Vic house with damp. They are known
_causes_ of damp in Vic houses. I'm sure you mean well, but Vic houses
do not work like modern buildings at all when it comes to damp.

http://www.periodproperty.co.uk/cgi-...sing/forum2.pl


NT

On Fri, 29 Oct 2004 16:15:30 +0100, Tony Bryer
wrote:

I'm of an age to remember the Rawlplug tool: a sort of masonry
drill in a metal handle that you hammered and rotated to make the
hole.

I've got a 12' long version of that - quarrying "star drill". The
same design is a few centuries old.

There's also the Rawl drill - a hand-cranked hammer drill.

--
Smert' spamionam

Well, it was given as an alternative to a mortar skim plus replaster of
the bottom metre or so, so I took it it was? Or are you recommending
replacing the plaster on *all* outside walls with this method?

IME penetrating damp usually manifests itself in the lower part of the wall.
Most of the rain runs down the wall, and only starts to soak in lower down.

Assuming the original plaster is ok, it's simply adding considerable cost.

If the originasl plaster is ok, it's a pretty good sign you don't have a
damp problem.

If you've cured the cause of penetrating damp by removing piled up soil
etc and made sure the pointing is sound - as you'd have to do anyway -
leaving things to dry out naturally in a habited house would be my advice.

Penetrating damp usually occurs where the mortar has degraded to the point
where it is porous or has developed hairline cracks at the join with the
bricks.