hi,

wondering if anyone could give me a little guidance here. i live in a
semi-detached house that need some repointing doing to the brickwork.
i'm thinking of having the whole lot done including the chimney. it's
standard red brick, nothing fancy but i was wondering if anybody could
give me a general idea about how much it's going to cost me. thanks
for any help

wrote in message
...
hi,

wondering if anyone could give me a little guidance here. i live in a
semi-detached house that need some repointing doing to the brickwork.
i'm thinking of having the whole lot done including the chimney. it's
standard red brick, nothing fancy but i was wondering if anybody could
give me a general idea about how much it's going to cost me. thanks
for any help

Suggest you contact Gun Point

http://www.gunpoint-south.co.uk/default.htm

You may find a branch more local to you. I used them several times for
brickwork repairs and repointing after subsidence damage and was always pleased
with the result. Can't remember square metre rate, sorry, but remember thinking
the cost was a lot lower than I had expected.

Peter

Peter Taylor wrote
Suggest you contact Gun Point

http://www.gunpoint-south.co.uk/default.htm

Maybe a better link is http://www.gunpointlimited.co.uk/conta1.htm

wondering if anyone could give me a little guidance here. i live in a
semi-detached house that need some repointing doing to the brickwork.

Whoever you use, first check to see that you don't have lime mortar. If
modern cementious mortar is used to repoint a lime mortar house, you could
cause serious damage and some of the brain dead spods that get contracted to
do the work wouldn't have a clue.

Christian.

"Christian McArdle" wrote in message . net...
wondering if anyone could give me a little guidance here. i live in a
semi-detached house that need some repointing doing to the brickwork.

Whoever you use, first check to see that you don't have lime mortar. If
modern cementious mortar is used to repoint a lime mortar house, you could
cause serious damage and some of the brain dead spods that get contracted to
do the work wouldn't have a clue.

I'm probably going to need some repointing done soon. I'm assuming
that my house (1900's terraced) will have been built using lime
mortar, right? Assuming so, what are my chances of finding a brickie
who will use it these days? Won't they all just want to use
cement-based stuff instead?

David

Lobster wrote:

"Christian McArdle" wrote in message . net...

wondering if anyone could give me a little guidance here. i live in a
semi-detached house that need some repointing doing to the brickwork.

Whoever you use, first check to see that you don't have lime mortar. If
modern cementious mortar is used to repoint a lime mortar house, you could
cause serious damage and some of the brain dead spods that get contracted to
do the work wouldn't have a clue.


I'm probably going to need some repointing done soon. I'm assuming
that my house (1900's terraced) will have been built using lime
mortar, right? Assuming so, what are my chances of finding a brickie
who will use it these days? Won't they all just want to use
cement-based stuff instead?



Nah. Its very fashionable. juts bang in hydrated line instead of
portland and slap it in.


David

The Natural Philosopher wrote in message ...
Nah. Its very fashionable. juts bang in hydrated line instead of
portland and slap it in.
And hope it doesn't rain for a couple of months. Hydraulic lime might be a
better bet

The Natural Philosopher wrote in message ...
Lobster wrote:

"Christian McArdle" wrote in message . net...

wondering if anyone could give me a little guidance here. i live in a
semi-detached house that need some repointing doing to the brickwork.

Whoever you use, first check to see that you don't have lime mortar. If
modern cementious mortar is used to repoint a lime mortar house, you could
cause serious damage and some of the brain dead spods that get contracted to
do the work wouldn't have a clue.


I'm probably going to need some repointing done soon. I'm assuming
that my house (1900's terraced) will have been built using lime
mortar, right? Assuming so, what are my chances of finding a brickie
who will use it these days? Won't they all just want to use
cement-based stuff instead?


Hi.

One point not mentioned yet is that sound mortar should never be
stripped out of old houses built with soft bricks. One should only
replace mortar that is loose and can be removed by hand. So you never
do a complete repoint, but always patch, and be prepared to patch
again several years later. The reason is that most of these houses
have been repointed already with cement, which is much stronger than
the bricks, and if you remove the cement it breaks part of the brick
away with it. You can do a lot of damage this way.


Regards, NT

stuart noble wrote:
The Natural Philosopher wrote...
Nah. Its very fashionable. juts bang in hydrated line instead of
portland and slap it in.
And hope it doesn't rain for a couple of months. Hydraulic lime might
be a better bet

Just use 1:1:6, or even approach 1:2:9.

J.B.

"Jerry Built" ] wrote in message . ..
stuart noble wrote: The Natural Philosopher wrote...

Nah. Its very fashionable. juts bang in hydrated line instead of
portland and slap it in.
And hope it doesn't rain for a couple of months. Hydraulic lime might
be a better bet

Just use 1:1:6, or even approach 1:2:9.

1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

Regards, NT

N. Thornton wrote:
1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

So what would you suggest, or an expert recommend?

--
Toby.

'One day son, all this will be finished'

Toby wrote in message ...
N. Thornton wrote:
1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

So what would you suggest, or an expert recommend?
I've always used a readymix general purpose mortar with 4 water:1 PVA. It
needs to be fairly thick to avoid getting it on the brick faces.

In article ,
"Toby" writes:
N. Thornton wrote:
1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

So what would you suggest, or an expert recommend?


--
Andrew Gabriel
Consultant Software Engineer

"Toby" wrote in message ...
N. Thornton wrote:
1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

So what would you suggest, or an expert recommend?

I'm no expert on this, I've just read a few papers on it, so I'd stick
my head in the sand and suggest asking an expert Seriously, when I
read it I was boggled with the complexity of what I thought was such a
simple thing.

I did discover one thing though, which is inclusion of 1% plastic
fibres increases longeveity by controlling cracks and increasing
strength under tension. The Victorians knew this principle, and it was
standard practice to include horsehair in their mixes because it
extended mortar life significantly.

I wish I could give us all a better answer. I still dont know what to
repoint the house with.


Regards, NT

N. Thornton wrote:
I wish I could give us all a better answer. I still dont know what to
repoint the house with.

I think we are in the same situation. This house has had about 10% repointed
with cement, and a survey stated it was poor, although doesn't seem at all
bad to me. Trouble is the front has very thin joints hence easy to make a
mess of. As this place will get sold within 5 years, I think I'll just give
the facade a scrub; this should give the mortar a fresher appearance so may
pass a casual inspection. I've used 1:1:6 mix on small jobs such as window
reveals and it seems to have performed just fine.

On the flip side, lime mortar houses circa 1900 are great for putting holes
in, as easy as Lego.

--
Toby.

'One day son, all this will be finished'

On the flip side, lime mortar houses circa 1900 are great for putting
holes in, as easy as Lego.

You've got to be joking! My 1909 house is terrible for putting holes in. The
mortar and brick are so soft, it is hard to drill anything without whole
bricks disintegrating.

I can often get one in by turning off hammer until it is an inch in. After
that, the hammer is required to advance, and very careful and delicate
hammer can sometimes get deeper without smashing the thing.

Christian.

Christian McArdle wrote:
On the flip side, lime mortar houses circa 1900 are great for putting
holes in, as easy as Lego.

You've got to be joking! My 1909 house is terrible for putting holes
in. The mortar and brick are so soft, it is hard to drill anything
without whole bricks disintegrating.

I can often get one in by turning off hammer until it is an inch in.
After that, the hammer is required to advance, and very careful and
delicate hammer can sometimes get deeper without smashing the thing.

Christian.

Well, I meant window sized holes, being careful not to end up with patio
door sized holes ;-)
But yes I agree. I have an intriguing 1st floor brick/lime mortar internal
dividing wall supported on a regular joist. I think the bricks must be the
Victorian equivalent of thermolites as there just does not seem to be any
substance to them. A stubborn finger is all that is needed to transform them
to dust (Discovered after attempting to fix basin to wall... :-(

--
Toby.

'One day son, all this will be finished'

In article ,
(N. Thornton) writes:
"Toby" wrote in message ...
N. Thornton wrote:
1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

So what would you suggest, or an expert recommend?

I'm no expert on this, I've just read a few papers on it, so I'd stick
my head in the sand and suggest asking an expert Seriously, when I
read it I was boggled with the complexity of what I thought was such a
simple thing.

It sure isn't simple, and neither is it the case that it's
completely understood. I used to have a neighbour who taught
brickwork, and his comment was that we're discovering what
we don't know about cement based mortars faster than we're
working how to use them properly. We know (or at least used
to know) much more about lime based mortars, since we've been
using them at least 200 times longer.

However, I recall reading somewhere a few years ago (possibly
in this newsgroup) that the BRE had experimented with various
cement/lime mixtures, and the 1:1 was quite good. Any less lime
and the mortar loses all the movement and self-repair qualities
of lime, so you'd be back to the problems you get repointing a
lime mortar house with cement. I think there were problems with
mixtures containing more lime too (until you get to pure lime
of course), but I can't recall what that was.

I did discover one thing though, which is inclusion of 1% plastic
fibres increases longeveity by controlling cracks and increasing
strength under tension. The Victorians knew this principle, and it was
standard practice to include horsehair in their mixes because it
extended mortar life significantly.

I've not come across it in mortar, but it's certainly used in
scratch coat lime plaster. This stops it cracking as the lime
mortar walls move around. The dot-n-dab plasterboard fixing
is loaded with plastic fibres too to give it tensile strength.
The tutor on my plastering course demonstrated how effective
that is by hanging his weight on a piece of board fixed up with
the stuff, and it showed no sign of giving way.

I wish I could give us all a better answer. I still dont know what to
repoint the house with.

Silicone bath sealant? ;-)

--
Andrew Gabriel

(N. Thornton) wrote in message . com...
"Toby" wrote in message ...
N. Thornton wrote:
1:1:6 is very common, but has been widely criticised by the experts,
since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

So what would you suggest, or an expert recommend?

I'm no expert on this, I've just read a few papers on it, so I'd stick
my head in the sand and suggest asking an expert Seriously, when I
read it I was boggled with the complexity of what I thought was such a
simple thing.

I did discover one thing though, which is inclusion of 1% plastic
fibres increases longeveity by controlling cracks and increasing
strength under tension. The Victorians knew this principle, and it was
standard practice to include horsehair in their mixes because it
extended mortar life significantly.

I wish I could give us all a better answer. I still dont know what to
repoint the house with.


Regards, NT

Wickes (in their Good Ideas Leaflet no. 12 at
http://www.wickes.co.uk/scat/goodideas )
advocate the addition of plasticiser to standard mortar to get the
benefit of lime mortar; ie making it not too rigid or hard. Anyone
had experience of this or care to comment?

David

In article ,
(Lobster) writes:

Wickes (in their Good Ideas Leaflet no. 12 at
http://www.wickes.co.uk/scat/goodideas )
advocate the addition of plasticiser to standard mortar to get the
benefit of lime mortar; ie making it not too rigid or hard. Anyone
had experience of this or care to comment?

I always use it when I'm not using lime. However, not everyone
is convinced it's a good idea.

I always use waterproofer too, with either lime or plasticiser.
(Sometimes I use all 3 if I only have a combined
plasticiser/waterproofer and want to use cement/lime mortar mix.)

--
Andrew Gabriel

"Christian McArdle" wrote in message . net...
Toby wrote:

As this place will get sold within 5 years, I think I'll just give
the facade a scrub; this should give the mortar a fresher appearance
so may
pass a casual inspection.

I've been warned not to do that as the bricks tend to become absorbent
and turn green. The accumulated muck keeps the water out apparently.

I've used 1:1:6 mix on small jobs such as window
reveals and it seems to have performed just fine.

If I understood it right it works but is weak, and will fail early.
Consider that decent cement or lime mixes should last over 50 years at
least. So 'early' might not be such a big problem.

I gather the best mix is lime and sand plus a pozzolan. Brick dust is
a pozzolan, I dont remember what the others are.


On the flip side, lime mortar houses circa 1900 are great for putting
holes in, as easy as Lego.

You've got to be joking! My 1909 house is terrible for putting holes in. The
mortar and brick are so soft, it is hard to drill anything without whole
bricks disintegrating.

I wonder if you have undercooked bricks, rejects. Old bricks are soft,
but they shouldnt be that bad. Usually the rejects were used on the
inner layer of wall, so Vic houses tend to look a right eyesore if the
plaster's stripped off, with broken, misshapen, burnt and undercooked
bricks galore. Perhaps an inexperienced builder was involved. Who
knows.


Regards, NT

I wonder if you have undercooked bricks, rejects. Old bricks are soft,
but they shouldnt be that bad. Usually the rejects were used on the
inner layer of wall, so Vic houses tend to look a right eyesore if the
plaster's stripped off, with broken, misshapen, burnt and undercooked
bricks galore. Perhaps an inexperienced builder was involved. Who
knows.

Well, the bricks I've seen drilled have all been inside, mostly in the
fireplace, as elsewhere they are covered in plaster, so I can't see what's
going on. About a quarter are black (but probably because they formed the
flue, although there isn't much of a pattern), most are cracked.

Christian.

Well, the bricks I've seen drilled have all been inside, mostly in the
fireplace, as elsewhere they are covered in plaster, so I can't see
what's going on. About a quarter are black (but probably because they
formed the flue, although there isn't much of a pattern), most are
cracked.

I should mention that the brick front facade is excellent with a mixture of
grey, yellow and red brick in the local Reading brick fashion. It's a shame
the presumably original roof slates haven't lasted as well.

Christian.

Andrew Gabriel wrote in message ...
However, I recall reading somewhere a few years ago (possibly
in this newsgroup) that the BRE had experimented with various
cement/lime mixtures, and the 1:1 was quite good. Any less lime
and the mortar loses all the movement and self-repair qualities
of lime,
Movement and self repair in regard to pointing amounts to something that
will wash away with the first rainfall. If the mortar *and* the pointing
were the same, maybe....

In article ,
"stuart noble" writes:

Andrew Gabriel wrote in message ...
However, I recall reading somewhere a few years ago (possibly
in this newsgroup) that the BRE had experimented with various
cement/lime mixtures, and the 1:1 was quite good. Any less lime
and the mortar loses all the movement and self-repair qualities
of lime,
Movement and self repair in regard to pointing amounts to something that
will wash away with the first rainfall. If the mortar *and* the pointing
were the same, maybe....

Long before portland cement, lime mortar brickwork usually had
some cement in the exterior pointing (exterior pointing was not
done as the bricks were layed, but later). Most of mine has lasted
100 years without any trouble, and where it hasn't, it's due to
some unreasonable influence happening subsequently like bridging
the damp poof course or failing to repair leaking gutter downpipes
(not me -- previous owners;-). There were also a couple of small
places where someone had repointed wrongly (in one of them, using
pure cement and no sand -- a bugger to get out).

--
Andrew Gabriel

Andrew Gabriel wrote in message ...
Long before portland cement, lime mortar brickwork usually had
some cement in the exterior pointing
I think a small amount of cement is just another pozzolan, but I wonder if
non-hydraulic lime alone has ever been successful externally.

"N. Thornton" wrote:
"Jerry Built" wrote...
Some other people wrote about pointing and what to mix to use:
juts bang in hydrated line instead of portland and slap it in.
And hope it doesn't rain for a couple of months. Hydraulic lime might
be a better bet

Just use 1:1:6, or even approach 1:2:9.

1:1:6 is very common, but has been widely criticised by the experts,

No it has not. See below.


since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

Erm, NT, I think you've become confused. This is doing people a
big dis-service. There is nothing wrong with 1:1:6. For a brief
and easy-to-understand look at the subject, please see:

http://www.buildingconservation.com/...ent/cement.htm
http://www.bricksandbrass.co.uk/diymats/lime/lime.htm

Please note carefully that above I said "approach 1:2:9".

A LOT of mis-information has recently been spouted by those with vested
interests in the lime production/use fields. 1:1:6 has been around for
a long time - about 150 years.


J.B.

"N. Thornton" wrote:
"Christian McArdle" wrote...
Toby wrote:

As this place will get sold within 5 years, I think I'll just give
the facade a scrub; this should give the mortar a fresher appearance
so may pass a casual inspection.

I've been warned not to do that as the bricks tend to become absorbent
and turn green. The accumulated muck keeps the water out apparently.

What is your source of information? It's fine to clean external
brickwork by non-destructive means. Things like sandblasting or
scabbling are right out though! You don't really want a build-up
of moss etc. on your house!


I've used 1:1:6 mix on small jobs such as window
reveals and it seems to have performed just fine.

If I understood it right it works but is weak, and will fail early.
Consider that decent cement or lime mixes should last over 50 years at
least. So 'early' might not be such a big problem.

See other post. I'm not trying to be nasty!


I gather the best mix is lime and sand plus a pozzolan. Brick dust is
a pozzolan, I dont remember what the others are.

Cement is a pozzolan, too!


On the flip side, lime mortar houses circa 1900 are great for putting
holes in, as easy as Lego.

You've got to be joking! My 1909 house is terrible for putting holes
in. The mortar and brick are so soft, it is hard to drill anything
without whole bricks disintegrating.

I had a job on Wed/Thu fixing skirting/picture rail, some to a party
wall. On the party wall I didn't use "hammer", just an ordinary drill
with a newly-sharpened masonry bit. No problem at all (LBC commons).
Not too noisy, either.

I wonder if you have undercooked bricks, rejects. Old bricks are soft,
but they shouldnt be that bad. Usually the rejects were used on the
inner layer of wall, so Vic houses tend to look a right eyesore if the
plaster's stripped off, with broken, misshapen, burnt and undercooked
bricks galore. Perhaps an inexperienced builder was involved. Who
knows.

Do you mean rejects, or regrades? Rejects are junk, cracked or mis-
shaped, used for hardcore etc. Regrades are bricks that are fine
except for slight damage and colour problems. You wouldn't want to
use them for facing. There are/were many, many types, textures and
colours of bricks. There is likely to be a "brick museum" or a "brick
library" at a BMs near you - for fun, 'phone up a few to see if anyone
knows where (or say approx. where you are & I'll see what I can do).
Obvious variations are from Staffordshire blues and similar which are
as hard as hell, to Baxi decorative bricks used in fireplaces, which
aren't as hard as your thumbnail.

Christian McArdle wrote:
[ the longevity of the bricks in his house ] It's a shame
the presumably original roof slates haven't lasted as well.

A problem with the fixings and corrosion?

J.B.
--

[ the longevity of the bricks in his house ] It's a shame
the presumably original roof slates haven't lasted as well.

A problem with the fixings and corrosion?

Not that I can tell. Most of the slates are still present, they've just
rotted away at the edges. They are 100 years old, though.

Christian.

"Jerry Built" ] wrote in message . ..
"N. Thornton" wrote:
"Jerry Built" wrote...

1:1:6 is very common, but has been widely criticised by the experts,

No it has not. See below.

since the lime content causes thr cement to not checmically set
properly, and the cement clogs the pores preventing the lime going off
properly as well. The result is regular failures. But its still
commonly used. I expect it'll take another 10 years for the knowledge
to permeate.

Erm, NT, I think you've become confused. This is doing people a
big dis-service. There is nothing wrong with 1:1:6. For a brief
and easy-to-understand look at the subject, please see:

http://www.buildingconservation.com/...ent/cement.htm
http://www.bricksandbrass.co.uk/diymats/lime/lime.htm

OK so if I understand correctly, according to this, 1:1:6 is fine, but
some cement lime mixes arent. I know little about lime mortars, I read
some articles and paper a year or so ago, some from English Heritage,
and the concensus of them all was that lime cement mixes should be
avoided. I guess, as the article you refer to says, there are
differences of opinion. I expect I'll be using 1:1:6 then, thanks for
the info.


Regards, NT

I shall stick my head above the parapet and call myself an expert ...

There is already mortar between the bricks, so the pointing is not
there to stick the bricks together. It is there as a sacrificial
layer.

Rain (water, salt, acid ...) is driven into the brick surface and then
when the weather improves, leaves by the easiest escape route. If the
pointing is weaker than the brick, then the easier route is through
the pointing. Over the (many) years this causes the pointing to wear
away and eventually the bricks will need repointing. This is a much
better situation to be in than if the pointing is stronger than the
bricks because then the surface of the brick wears away leaving the
soft core exposed which wears away quickly. OUCH!

Consider three situations:

Old soft bricks, pointed with lime mortar. Lime mortar is weak, even
with a pozzolan added, so the bricks will be OK.

Modern, hard bricks pointed with cement. So long as the cement mix is
fairly weak this should be OK too. I'm not a cement expert so I assume
that others know better than me and that a that a
1cement:1lime:6aggregate mix is OK. (The lime is just there as a
plasticiser and a red herring)

Old soft bricks pointed with cement. The cement is stronger than the
bricks so producing the effect which I can see outside the window as I
sit here. An old red brick wall has a grid of cement pointing but the
bricks in between the pointing have worn back by about 10mm since it
was done. This is a problem which has shown up particularly in the
last 50 years, partly because late 20thC builders have no experience
of lime mortar, but also because Portland cement today is MUCH
stronger than the cement of 100 years ago.

The thing to understand is that a weak mortar is not a poor mortar.
The mortar must be weaker than the brick.

I shall create another message about pozzolans which seem to be
causing a lot of confusion.
--
~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plasterwork, plaster conservation
/ ^^ \ // Freehand modelling and pargeting
|____| www.kettlenet.co.uk 07976 649862

If you want to be picky, then the word pozzolan only applies to
volcanicash from Pozzolano in Italy. I shall use the word pozzolan in
a much more general way and the pozzolan which is normally used today
in UK is brick dust.

Pozzolans are impurities which are added to a pure lime mortar to give
it some cementitious properties; to make it harder and more
impermeable to water. When lime putty mortar is used outdoors, then
pozzolans are always added to give it some extra weather resistance.

Hydraulic lime mortar contains natural pozzolans, so is fine for using
outdoors without any more additives.

Hydrated lime should be put in a tub of water for a couple of days
when lo and behold it becomes lime putty. Pozzolans can then be added
for external work.

Once pozzolans have been added to lime putty mortar, it will start to
set and so normally is used the same day.

To say that hydraulic lime (or lime putty mortar + pozzolan) have
cementitious properties is misleading because todays cement is MUCH
stronger than either. I don't have the figures to hand but my dodgy
memory thinks that todays cement is about 10 times as strong as
cements of 150 years ago and 20 times as strong as hydraulic lime
mortar. Castle Cement have done lots of research on this.

Until a few years ago, a little Portland cement was often added to
lime mortar to act as a pozzolan but there were too many mortar
failures so English Heritage commissioned some research.

The results of the research were published as "The Smeaton Report" and
in summary the report says that that cement+lime mixes will succeed if
there is enough cement in the mix to get a _cement_ set. The lime is
there just to provide plasticity.

What does NOT work is a mix where 'just a little' cement is used as a
pozzolan because the cement clogs up the pores of the lime so the air
and water which are required for a _lime_ set can't get into the
matrix.
Mortar failure is likely because there is a poor lime set and
not enough cement for a cement set.


--
~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plasterwork, plaster conservation
/ ^^ \ // Freehand modelling and pargeting
|____| www.kettlenet.co.uk 07976 649862

differences of opinion. I expect I'll be using 1:1:6 then, thanks for
the info.

I always use 3 to 1 mix for pointing, any specific reason you have to use lime?
Are you matching in to some old pointing? Tel

"Jerry Built" ] wrote in message . ..
"N. Thornton" wrote:
"Christian McArdle" wrote...
Toby wrote:

As this place will get sold within 5 years, I think I'll just give
the facade a scrub; this should give the mortar a fresher appearance
so may pass a casual inspection.

I've been warned not to do that as the bricks tend to become absorbent
and turn green. The accumulated muck keeps the water out apparently.

What is your source of information? It's fine to clean external
brickwork by non-destructive means. Things like sandblasting or
scabbling are right out though! You don't really want a build-up
of moss etc. on your house!

Am I allowed to have my house sandblasted (to be followed up by
repointing and coating with waterproofer)? It's worrying me; but how
else do I remove all the old bits of crud and cement left behind when
the render was hacked off, to restore the facade both aesthetically
and functionally?

Thanks
David

"Jerry Built" ] wrote in message . ..
"N. Thornton" wrote:
"Christian McArdle" wrote...
Toby wrote:

As this place will get sold within 5 years, I think I'll just give
the facade a scrub; this should give the mortar a fresher appearance
so may pass a casual inspection.

I've been warned not to do that as the bricks tend to become absorbent
and turn green. The accumulated muck keeps the water out apparently.

What is your source of information? It's fine to clean external
brickwork by non-destructive means.

I cant remember Im afraid. Youre saying scrubbing old bricks up wont
make them go green? Thinking about it it makes sense. I expect only if
they have water sitting or splashing on them theyre likely to green.


Things like sandblasting or
scabbling are right out though! You don't really want a build-up
of moss etc. on your house!

I've got that. What's the best action?


You've got to be joking! My 1909 house is terrible for putting holes
in. The mortar and brick are so soft, it is hard to drill anything
without whole bricks disintegrating.

I wonder if you have undercooked bricks, rejects. Old bricks are soft,
but they shouldnt be that bad. Usually the rejects were used on the
inner layer of wall, so Vic houses tend to look a right eyesore if the
plaster's stripped off, with broken, misshapen, burnt and undercooked
bricks galore. Perhaps an inexperienced builder was involved. Who
knows.

Do you mean rejects, or regrades? Rejects are junk, cracked or mis-
shaped, used for hardcore etc. Regrades are bricks that are fine
except for slight damage and colour problems.

Rejects. In Victorian times as many as 50% of bricks made on site were
rejects: broken, cracked, funny shaped, undercooked and too soft, etc.
Bricks were generally made by itinerant gangs who came to the site,
dug up the clay and burnt the bricks on site. Later pressed bricks
took over. Aesthetically the hand made bricks are far nicer, but the
reject rate was high, and the junk was normally used for the inner
skin of the wall.

I just wondered if you might be going into undercooked bricks there.


You wouldn't want to
use them for facing. There are/were many, many types, textures and
colours of bricks. There is likely to be a "brick museum" or a "brick
library" at a BMs near you - for fun, 'phone up a few to see if anyone
knows where (or say approx. where you are & I'll see what I can do).

Theres a good site online, cw lots of piccies, I lost the address
though.


Regards, NT

In article , stuart
noble writes

Andrew Gabriel wrote in message ...
Long before portland cement, lime mortar brickwork usually had
some cement in the exterior pointing
I think a small amount of cement is just another pozzolan, but I wonder if
non-hydraulic lime alone has ever been successful externally.

My house is rendered in hydraulic lime and sand, which gives it a
wonderful mushroom colour. We were going to limewash it, but liked the
finish so much we decided to leave it alone.

John
--
John Rouse

Lobster wrote:
"Jerry Built" wrote...
It's fine to clean external
brickwork by non-destructive means. Things like sandblasting or
scabbling are right out though! You don't really want a build-up
of moss etc. on your house!

Am I allowed to have my house sandblasted (to be followed up by
repointing and coating with waterproofer)? It's worrying me; but how
else do I remove all the old bits of crud and cement left behind when
the render was hacked off, to restore the facade both aesthetically
and functionally?

To some extent it depends on the brick, but it's not generally
a good idea outside! The brickwork can be made much more susceptible
to water absorbtion and spalling. The operator's technique and the
"sand" used to blast clean are factors too. What sort of bricks
is the construction of? As a matter of interest, why was the render
removed, and was it an original feature? If you have not too much
to clean up, could you use brick cleaner (acid based)?


J.B.