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Default Porous brickwork and treatment

Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...e-Treatments/1

although the solvent-based one looks a bit nasty!

Any suggestions please?
--
Peter.
The gods will stay away
whilst religions hold sway
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On 17 Aug, 09:25, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...s/26,Surface-T...

although the solvent-based one looks a bit nasty!

Any suggestions please?
--
Peter.
The gods will stay away
whilst religions hold sway


AIUI, there's 2 families of waterproofing treatments - there's the non-
breathable silicon-based ones (Thompsons WaterSeal being the best
known http://www.thompsonsweatherproofing....oduct.jsp?id=1
) - and there's the much more expensive but water-vapour-permeable
silane/siloxane based ones (which are less well known, but Liquid
Plastics K501 is an example http://www.liquidplastics.co.uk/Deco...ngs-for-Walls).

As you've already found out, there's also a division between water-
based and solvent-based versions of silicone treatment. AIUI solvent-
based are the older generation products (I believe silane/siloxane
treatments were also solvent based at one time, but have already been
discontinued).

I've treated a large Victorian building built from very soft red
bricks with K501, because the brickfaces were spalling from frost
damage. This was 2 years ago - and the last 2 winters have shown the
spalling has been completely halted.

With my building it was wise to bear the considerable extra cost of a
breathable treatment, as it's unlikely that all points of water (rain)
penetration could be sealed - and the solution relies on controlling
the level of moisture in the brickfaces (by permitting it to pass out
again as water vapour) down to the point that spalling is stopped.

I can't tell you what will be right for your building, or even if it
is necessary, but bear in mind these treatments are non-reversible -
so do you homework before plunging in.

Can you post a close-up pic of the damage, and another showing the
extent of the problem?
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Default Porous brickwork and treatment

PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork
being porous.
About that time I had to drill a couple of holes in the gable wall -
it faces SW - and the debris was like a crumbly paste rather than
dust for about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove -
which I think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on
it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...e-Treatments/1

although the solvent-based one looks a bit nasty!

Any suggestions please?


Liquid Plastics K501 is the dogs danglies


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On Aug 17, 9:25*am, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...s/26,Surface-T...

although the solvent-based one looks a bit nasty!

Any suggestions please?



More or less all above ground wall bricks are porous. What you propose
is a classic mistake. Read SPAB's guidance on such things if you're
still tempted.


NT
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Default Porous brickwork and treatment

On 17 Aug, 12:24, Tabby wrote:
On Aug 17, 9:25*am, PeterC wrote:



Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.


Is it worth treating the wall and, if so, what sort of gunk to put on it?


There are 2 possibilities on this page


http://www.everbuild.co.uk/products/...s/26,Surface-T...


although the solvent-based one looks a bit nasty!


Any suggestions please?


More or less all above ground wall bricks are porous. What you propose
is a classic mistake. Read SPAB's guidance on such things if you're
still tempted.

NT


I've read the SPAB advice (and been on a couple of of their very good
training courses) - but I disagree with their purist standpoint on
masonry treatments.

They would have you cut out and replace every spalled brick. In my
case that would have been several thousand bricks. A cure is no cure -
if it bankrupts the customer.

I asked a lot of different people, got a lot of different answers -
but the best advice I got was "it depends", and that for my situation
silane/siloxane was the solution *most likely* to make a sane
compromise.

So far - results have borne this out.

If you live in a scheduled ancient monument you'll probably have to do
it the hard way, similarly if the problem is small (or your wallet
very large) it's probably no hardship to go for the rolls-royce
solution. For the rest of us, there's compromise.


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On Aug 17, 2:56*pm, " wrote:
On 17 Aug, 12:24, Tabby wrote:
On Aug 17, 9:25*am, PeterC wrote:


Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.


Is it worth treating the wall and, if so, what sort of gunk to put on it?


There are 2 possibilities on this page


http://www.everbuild.co.uk/products/...s/26,Surface-T....


although the solvent-based one looks a bit nasty!


Any suggestions please?


More or less all above ground wall bricks are porous. What you propose
is a classic mistake. Read SPAB's guidance on such things if you're
still tempted.


NT


I've read the SPAB advice (and been on a couple of of their very good
training courses) - but I disagree with their purist standpoint on
masonry treatments.


its simply based on properly understanding whats known on the subject


They would have you cut out and replace every spalled brick. In my
case that would have been several thousand bricks. A cure is no cure -
if it bankrupts the customer.


Saying the ideal is to replace a spalled brick, but that replacing 100
isnt practical is just stating the obvious. I dont think claiming spab
wants you to replace 1000s of bricks on a terraced house is very
credible. Its also got nothing to do with the question in hand.


I asked a lot of different people, got a lot of different answers -
but the best advice I got was "it depends", and that for my situation
silane/siloxane was the solution *most likely* to make a sane
compromise.


yes, the usual confused & often ignorant advice


So far - results have borne this out.

If you live in a scheduled ancient monument you'll probably have to do
it the hard way, similarly if the problem is small (or your wallet
very large) it's probably no hardship to go for the rolls-royce
solution. For the rest of us, there's compromise.



some calm logic could help


NT
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some calm logic could help


NT


Then stay away from conservationists.
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stuart noble wrote:

some calm logic could help


NT


Then stay away from conservationists.

ROFLMAO.
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On Tue, 17 Aug 2010 02:18:37 -0700 (PDT), wrote:

On 17 Aug, 09:25, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...s/26,Surface-T...

although the solvent-based one looks a bit nasty!

Any suggestions please?
--
Peter.
The gods will stay away
whilst religions hold sway


AIUI, there's 2 families of waterproofing treatments - there's the non-
breathable silicon-based ones (Thompsons WaterSeal being the best
known http://www.thompsonsweatherproofing....oduct.jsp?id=1
) - and there's the much more expensive but water-vapour-permeable
silane/siloxane based ones (which are less well known, but Liquid
Plastics K501 is an example http://www.liquidplastics.co.uk/Deco...ngs-for-Walls).

As you've already found out, there's also a division between water-
based and solvent-based versions of silicone treatment. AIUI solvent-
based are the older generation products (I believe silane/siloxane
treatments were also solvent based at one time, but have already been
discontinued).


Thanks for this info - wondered about the relative merits of solvent/non.

I've treated a large Victorian building built from very soft red
bricks with K501, because the brickfaces were spalling from frost
damage. This was 2 years ago - and the last 2 winters have shown the
spalling has been completely halted.

No spalling of bricks at all; some shallow, inadequate, repointing coming
off on the gable triangle but the rest is OK.

With my building it was wise to bear the considerable extra cost of a
breathable treatment, as it's unlikely that all points of water (rain)
penetration could be sealed - and the solution relies on controlling
the level of moisture in the brickfaces (by permitting it to pass out
again as water vapour) down to the point that spalling is stopped.

I can't tell you what will be right for your building, or even if it
is necessary, but bear in mind these treatments are non-reversible -
so do you homework before plunging in.

Can you post a close-up pic of the damage, and another showing the
extent of the problem?


Apart from the minor bit mentioned above, there's none to see. It's only
the obvious slight dampness to 20mm or so that worried me. It also must
remove a lot of heat from the wall in cold weather when there's a goodly
wind.
--
Peter.
The gods will stay away
whilst religions hold sway
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On Tue, 17 Aug 2010 10:27:35 +0100, Pete Zahut wrote:

PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork
being porous.
About that time I had to drill a couple of holes in the gable wall -
it faces SW - and the debris was like a crumbly paste rather than
dust for about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove -
which I think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on
it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...e-Treatments/1

although the solvent-based one looks a bit nasty!

Any suggestions please?


Liquid Plastics K501 is the dogs danglies


I'd rather avoid coating the wall. I prefer something that soaks in and
that can easily be renewed by simply spraying on another dollop (I've never
like paint on exterior wood and use other treatments where possible).
--
Peter.
The gods will stay away
whilst religions hold sway


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On Tue, 17 Aug 2010 04:24:44 -0700 (PDT), Tabby wrote:

On Aug 17, 9:25*am, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...s/26,Surface-T...

although the solvent-based one looks a bit nasty!

Any suggestions please?


More or less all above ground wall bricks are porous. What you propose
is a classic mistake. Read SPAB's guidance on such things if you're
still tempted.

NT


Well, there's no spalling and post-war ex-council house isn't historic!

SPAB says that one cause is frost on damp bricks; I can't stop frost or
rain, so doing nothing might eventually lead to spalling.
A poromeric coating would shift the equilibrium by excluding water and
allowing vapour to pass through. With heating inside and heat from the sun
outside this should work.
--
Peter.
The gods will stay away
whilst religions hold sway
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On 18/08/2010 13:57, PeterC wrote:
On Tue, 17 Aug 2010 10:27:35 +0100, Pete Zahut wrote:

PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork
being porous.
About that time I had to drill a couple of holes in the gable wall -
it faces SW - and the debris was like a crumbly paste rather than
dust for about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove -
which I think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on
it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...e-Treatments/1

although the solvent-based one looks a bit nasty!

Any suggestions please?


Liquid Plastics K501 is the dogs danglies


I'd rather avoid coating the wall. I prefer something that soaks in and
that can easily be renewed by simply spraying on another dollop (I've never
like paint on exterior wood and use other treatments where possible).


But isn't the K501 a silane/siloxane product? AIUI this is not a
coating, but a series of silicone-like particles that can move about
within the brickwork. They simply occupy space that would otherwise
contain water.
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On Wed, 18 Aug 2010 14:47:20 +0100, stuart noble wrote:

On 18/08/2010 13:57, PeterC wrote:
On Tue, 17 Aug 2010 10:27:35 +0100, Pete Zahut wrote:

PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork
being porous.
About that time I had to drill a couple of holes in the gable wall -
it faces SW - and the debris was like a crumbly paste rather than
dust for about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove -
which I think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on
it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...e-Treatments/1

although the solvent-based one looks a bit nasty!

Any suggestions please?

Liquid Plastics K501 is the dogs danglies


I'd rather avoid coating the wall. I prefer something that soaks in and
that can easily be renewed by simply spraying on another dollop (I've never
like paint on exterior wood and use other treatments where possible).


But isn't the K501 a silane/siloxane product? AIUI this is not a
coating, but a series of silicone-like particles that can move about
within the brickwork. They simply occupy space that would otherwise
contain water.


Ah, sorry - the name rather suggested a coating. Having looked at the data
sheet, it does look good. Thanks for the info.
--
Peter.
The gods will stay away
whilst religions hold sway
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On 17 Aug, 09:25, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...s/26,Surface-T...

although the solvent-based one looks a bit nasty!

Any suggestions please?
--
Peter.
The gods will stay away
whilst religions hold sway


Dear Peter
Brick is supposed to be porous. If it is not causing any problem do
not treat it. If, however, it is accumulating water to the extent
that you are getting frost damage or loosing heat badly then I see no
reason why you cannot treat the brick. All treatment ideally should
be reversible in accordance with good SPAB practice and the idea of
putting on a layer of silicone is not a good one. If , however, you
can infuse the silane based products mentioned but others in this
thread it is naturally removed over a period of decades and as far as
we know can do no harm. BRE did work with silanes some 30 plus years
ago on statues that were degrading (I think limestone but cant
remember)
I know the firm Safeguard, having bought from them for 35 years or
more and they are reputable and have their own research PhD a chap
called Eric ? with whom I have spoken in the past and you could do far
worse than them
http://www.safeguardeurope.com/appli...enetration.php
If you are interested

Chris
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chris wrote:
On 17 Aug, 09:25, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.

Is it worth treating the wall and, if so, what sort of gunk to put on it?

There are 2 possibilities on this page

http://www.everbuild.co.uk/products/...s/26,Surface-T...

although the solvent-based one looks a bit nasty!

Any suggestions please?
--
Peter.
The gods will stay away
whilst religions hold sway


Dear Peter
Brick is supposed to be porous. If it is not causing any problem do
not treat it. If, however, it is accumulating water to the extent
that you are getting frost damage or loosing heat badly then I see no
reason why you cannot treat the brick.


Thats right. I have rendered walls and some north facing bits were
spalling, but not others. I traced it to rain bouncing off the window
drip boards and making the wall above slightly damp. Those areas ALONE
have been treated and repainted, and the damage has stopped.

Otherwise the walls dry out naturally enough.


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On Aug 18, 2:04*pm, PeterC wrote:
On Tue, 17 Aug 2010 04:24:44 -0700 (PDT), Tabby wrote:
On Aug 17, 9:25*am, PeterC wrote:
Last Autumn there was a mention in a thread about 1950's brickwork being
porous.
About that time I had to drill a couple of holes in the gable wall - it
faces SW - and the debris was like a crumbly paste rather than dust for
about 15 - 20mm in.
The bricks are heavily patterned - a vertical herringbone groove - which I
think are Rustic(?) from c. 1950.


Is it worth treating the wall and, if so, what sort of gunk to put on it?


There are 2 possibilities on this page


http://www.everbuild.co.uk/products/...s/26,Surface-T....


although the solvent-based one looks a bit nasty!


Any suggestions please?


More or less all above ground wall bricks are porous. What you propose
is a classic mistake. Read SPAB's guidance on such things if you're
still tempted.


NT


Well, there's no spalling and post-war ex-council house isn't historic!

SPAB says that one cause is frost on damp bricks; I can't stop frost or
rain, so doing nothing might eventually lead to spalling.
A poromeric coating would shift the equilibrium by excluding water and
allowing vapour to pass through. With heating inside and heat from the sun
outside this should work.



You need to get the problem udnerstood before looking at solutions.
And in your case there is no problem. Pretty much all bricks are
porous and get wet and freeze, this doesnt cause spalling. Spalling
only happens if the bricks are so saturated with water that the only
way for the freezing water to expand is by pushing the brick face off.

No problem, nothing to solve. This is well demonstrated by the fact
that the brickwok has been coping just fine for 50 years.


Siloxane coatings, if repeated, clog the evaporations paths, then
damage can result.

SPAB is criticised here by those that havent read what they say &
taken the time to understand it. However they do know their stuff on
this topic. It turns out the way old houses handle dampness is a fair
bit different to what people thought a couple of decades ago, and to
some degree some of the same principles apply to more modern builds
too.


NT
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On Wed, 18 Aug 2010 19:20:11 +0100, The Natural Philosopher wrote:

chris wrote:



Dear Peter
Brick is supposed to be porous. If it is not causing any problem do
not treat it. If, however, it is accumulating water to the extent
that you are getting frost damage or loosing heat badly then I see no
reason why you cannot treat the brick.


Thats right. I have rendered walls and some north facing bits were
spalling, but not others. I traced it to rain bouncing off the window
drip boards and making the wall above slightly damp. Those areas ALONE
have been treated and repainted, and the damage has stopped.

Otherwise the walls dry out naturally enough.


D'you know, I was thinking about that yesterday (might have been due to the
Liquid Plastics treatment being several hundred quid): if the bricks
themselves aren't spalling then there can't be that much water in them and,
as you say, if they've been OK for 60 years...

So, thanks Tabby, Chris and TNP fo 'confirmation' and thanks to others for
the v. useful information and links.

I'll see what happens this Winter then, if I do anything at all, a
treatment will last 10 years+ and probably won't be necessary at all.
--
Peter.
The gods will stay away
whilst religions hold sway
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On 18 Aug, 22:36, Tabby wrote:

SPAB is criticised here by those that havent read what they say &
taken the time to understand it. However they do know their stuff on
this topic. It turns out the way old houses handle dampness is a fair
bit different to what people thought a couple of decades ago, and to
some degree some of the same principles apply to more modern builds
too.



interesting - gorra link?

Jim K
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Siloxane coatings, if repeated, clog the evaporations paths, then
damage can result.

Siloxane isn't a coating. It doesn't form a film. Get a grip man.
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On Thu, 19 Aug 2010 00:33:16 -0700 (PDT), Jim K wrote:

On 18 Aug, 22:36, Tabby wrote:

SPAB is criticised here by those that havent read what they say &
taken the time to understand it. However they do know their stuff on
this topic. It turns out the way old houses handle dampness is a fair
bit different to what people thought a couple of decades ago, and to
some degree some of the same principles apply to more modern builds
too.


interesting - gorra link?

Jim K


http://www.spab.org.uk/

http://www.spab.org.uk/advice/techni...a-2-brickwork/
--
Peter.
The gods will stay away
whilst religions hold sway


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PeterC wrote:
On Thu, 19 Aug 2010 00:33:16 -0700 (PDT), Jim K wrote:

On 18 Aug, 22:36, Tabby wrote:
SPAB is criticised here by those that havent read what they say &
taken the time to understand it. However they do know their stuff on
this topic. It turns out the way old houses handle dampness is a fair
bit different to what people thought a couple of decades ago, and to
some degree some of the same principles apply to more modern builds
too.

interesting - gorra link?

Jim K


http://www.spab.org.uk/

http://www.spab.org.uk/advice/techni...a-2-brickwork/


All damp control is a balance between keeping the water out, and letting
it escape if it gets in.

Since the two solutions are normally diametrically opposed, this gives
rise to conflicting advice.

Breathable shower proof coatings are perhaps the best of both worlds

In general you want to waterproof excessively wet areas (areas subject
to driving rain or standing in wet soil) , but let more sheltered areas
breath.

This leads directly to modern ways to deal with damp: High quality
engineering brick below ground with strong impermeable morytar, so that
water is unable to penetrate the wall and frost spalling below damp
proof is very unlikely.

Then a DPC, that limits the rise of the ground water, and more or less
making sure that walls are overhung by eaves and those are guttered, to
take water away from the walls. Also no paving near the house that can
cause splashing onto the wall above DPC. In addition, no flat projecting
surfaces like drip boards above windows, as these will act to collect
water. These should be sloped.

Its very rare to get driving rain IMMEDIATELY followed by a heavy frost.

So provided the rain soaked brickwork can lose its wetness in a day or
so, that's generally enough to avoid frost spallation.

Areas where water collects..bases of parapets or internal corners (in my
case window drip boards) may need treating LOCALLY.. All that consists
of is filling the voids in the brickwork with something else, so water
wont soak in.

In my case spallation was confined to three areas, Working out WHY there
was instructive.

All were on the north west side in deep shade. the direction the rain
comes from and where the sun don't shine..

Two were directly above lead faced sloping drip boards. One might assume
that water ran down and collected in the base of the wall above the drip
board...

The third was directly above where I had carelessly left a scrap
horizontal slate covering the gravel surround of the house. Water had
bounced off it and saturated the wall. I removed the slate, problem when
away.








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On Aug 19, 8:33*am, Jim K wrote:
On 18 Aug, 22:36, Tabby wrote:



SPAB is criticised here by those that havent read what they say &
taken the time to understand it. However they do know their stuff on
this topic. It turns out the way old houses handle dampness is a fair
bit different to what people thought a couple of decades ago, and to
some degree some of the same principles apply to more modern builds
too.


interesting - gorra link?

Jim K


Just read any SPAB damp related pamphlets for basic info. If you want
it explained more, check out the periodpropertyuk forum. Its not a
trivial subject though.

There are plenty of people making common wrong assumptions, a classic
one being that damp moves from the outside of a house inward, and thus
coating the outside helps. In fact overall vapour movement is from
inside to out, and coating the outside increases water content in
walls by blocking evaporation. There are several common misperceptions
on this topic.


NT
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On Aug 19, 8:37*am, stuart noble wrote:
Siloxane coatings, if repeated, clog the evaporations paths, then
damage can result.


Siloxane isn't a coating. It doesn't form a film. Get a grip man.


It soaks in and coats the particles, reducing water absorption and
evaporation. But when applied repeatedly it builds up, blocking pores,
forming a coating. It just isnt a useful part of damp control.


NT
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On Thu, 19 Aug 2010 13:55:43 +0100, The Natural Philosopher wrote:


All damp control is a balance between keeping the water out, and letting
it escape if it gets in.

Since the two solutions are normally diametrically opposed, this gives
rise to conflicting advice.

Breathable shower proof coatings are perhaps the best of both worlds

Yes, shift the equilibrium towards less wet.

In general you want to waterproof excessively wet areas (areas subject
to driving rain or standing in wet soil) , but let more sheltered areas
breath.

This leads directly to modern ways to deal with damp: High quality
engineering brick below ground with strong impermeable morytar, so that
water is unable to penetrate the wall and frost spalling below damp
proof is very unlikely.


Mine is just 2 courses of blue bricks, which I prefer to a DPC only. Every
Autumn I brush the walls to about 4 - 5 courses up to remove any dust; also
keep ant-heaps etc. cleared away.

Then a DPC, that limits the rise of the ground water, and more or less
making sure that walls are overhung by eaves and those are guttered, to
take water away from the walls. Also no paving near the house that can
cause splashing onto the wall above DPC. In addition, no flat projecting
surfaces like drip boards above windows, as these will act to collect
water. These should be sloped.


My eaves are small front and back and none at all on the gable end.
The concrete path runs adjacent to the house along the SW wall as the
'front' door is in the end (side) of the house - can't do anything about
that.

Its very rare to get driving rain IMMEDIATELY followed by a heavy frost.

So provided the rain soaked brickwork can lose its wetness in a day or
so, that's generally enough to avoid frost spallation.

Or ensure that the brickwork doesn't get saturated.

Areas where water collects..bases of parapets or internal corners (in my
case window drip boards) may need treating LOCALLY.. All that consists
of is filling the voids in the brickwork with something else, so water
wont soak in.

In my case spallation was confined to three areas, Working out WHY there
was instructive.

All were on the north west side in deep shade. the direction the rain
comes from and where the sun don't shine..

Two were directly above lead faced sloping drip boards. One might assume
that water ran down and collected in the base of the wall above the drip
board...

The third was directly above where I had carelessly left a scrap
horizontal slate covering the gravel surround of the house. Water had
bounced off it and saturated the wall. I removed the slate, problem when
away.



--
Peter.
The gods will stay away
whilst religions hold sway
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