Sealing porous brick wall - advice sought
 

I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?
And if so what?

Any suggestions or advice gratefully received.

--
Timothy Murphy
e-mail (80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

"Timothy Murphy" wrote in message
...
I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?
And if so what?

Any suggestions or advice gratefully received.

--
Timothy Murphy

Liquid Plastics do a lot of different stuff but I think it's the K501 that
you need to waterproof brickwork http://www.liquidplastics.co.uk/fset.htm

John.

Timothy Murphy wrote:
I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?
And if so what?

Any suggestions or advice gratefully received.


I've never found anything that really works. I've totally flooded walls
with Thomsons Waterseal and it's made virtually no difference. A bit
like trying to seal a loaf of bread I suppose.
Re-pointing helps a lot but, if the bricks themselves are porous, it's
not a total solution.

Stuart Noble wrote:
Timothy Murphy wrote:

I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?


I've never found anything that really works. I've totally flooded walls
with Thomsons Waterseal and it's made virtually no difference. A bit

Actually I've used it in these circs pretty successfully. After it was
applied, when it rained you could easily see the area of outside wall
where I'd applied it, as the brickwork stayed pale-coloured and
moisture-free whereas elsewhere it went dark as water soaked in.

I'm never quite sure whether it's a good idea to use it though, ie,
you're sealing a wall which is meant to be able to breathe.

David

On Fri, 30 Sep 2005 03:15:19 +0100, Timothy Murphy
wrote:

I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?
And if so what?

Any suggestions or advice gratefully received.

There has been a few threads on this in the past, something siloxane
based should be best, as long as the brick isn't tooo porous:

http://groups.google.co.uk/groups?hl=en&lr=&q=group%3Auk.d-i-y+seal+brick&qt_s=Search
http://groups.google.co.uk/groups?q=group%3Auk.d-i-y%20siloxane%20&hl=en&lr=&sa=N&tab=wg
http://www.google.co.uk/search?hl=en&safe=off&c2coff=1&q=site%3A.co.uk+sil oxane+sealer&btnG=Search

Better to get something from a specialist company dealing with stone
facades and get their advice rather than something cheap from the
local shed.

cheers,
Pete.

Timothy Murphy wrote:
Can I get a spray which will seal the wall?
Or should I apply something with a brush?
And if so what?

Tim,
I have sealed porus pots and a toilet bowl, with an invisible
hairline crack, using PVA glue diluted to a milky consistency. With
the pot I just swilled it around for a few minutes, left it to stand
for ten minutes and then threw the excess away. With the toilet I just
left it in the bowl overnight and flushed it away in the morning. That
was 24 years ago and we're still sitting on the same one.

If your wall isn't too big you could apply it with a plant spreyer.

Chris.
PS - (Played Cricket on the grounds of Trinity when it celebrated 400
years.)

Timothy Murphy wrote:
I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?
And if so what?

Any suggestions or advice gratefully received.


Mistake mistake. I'm not going to sit and type the full story of why
yet again. Short answer is repoint if the pointings bad, and fix any
other sources of water such as overflowing gutters etc. Rain does not
blow thru bricks, though it can blow through bad pointing.

http://www.periodproperty.co.uk/cgi-...ing/forum2.pl?
for full explanations, advice etc

NT

Pete C wrote:

I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

There has been a few threads on this in the past, something siloxane
based should be best, as long as the brick isn't tooo porous:


http://groups.google.co.uk/groups?hl=en&lr=&q=group%3Auk.d-i-y+seal+brick&qt_s=Search

http://groups.google.co.uk/groups?q=group%3Auk.d-i-y%20siloxane%20&hl=en&lr=&sa=N&tab=wg

http://www.google.co.uk/search?hl=en&safe=off&c2coff=1&q=site%3A.co.uk+sil oxane+sealer&btnG=Search

Thanks for all the responses.

I guess the problem could just be the pointing, as some suggested.
The brick is badly eroded, but the pointing is worse.
So I'll try re-pointing first
(actually, I think I will get a professional to do it)
and see if that solves the problem.

--
Timothy Murphy
e-mail (80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

Timothy Murphy wrote:
Pete C wrote:

I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

There has been a few threads on this in the past, something siloxane
based should be best, as long as the brick isn't tooo porous:


http://groups.google.co.uk/groups?hl=en&lr=&q=group%3Auk.d-i-y+seal+brick&qt_s=Search

http://groups.google.co.uk/groups?q=group%3Auk.d-i-y%20siloxane%20&hl=en&lr=&sa=N&tab=wg

http://www.google.co.uk/search?hl=en&safe=off&c2coff=1&q=site%3A.co.uk+sil oxane+sealer&btnG=Search

Thanks for all the responses.

I guess the problem could just be the pointing, as some suggested.
The brick is badly eroded, but the pointing is worse.
So I'll try re-pointing first
(actually, I think I will get a professional to do it)
and see if that solves the problem.

Since your wall is old soft porous brick, you should use lime mortar
(3:1). Cement is the main cause of soft brick deterioration, and would
only make it signficantly worse in time.

If the bricks are disintegrating badly, a coat of lime render should
stabilise them. But dont use cement, cement render is about the worst
option for soft brick walls.


NT

In article ,
says...
snip
I guess the problem could just be the pointing, as some suggested.
The brick is badly eroded, but the pointing is worse.
So I'll try re-pointing first
(actually, I think I will get a professional to do it)
and see if that solves the problem.

Make sure he uses lime mortar, not Portland cement.

Lobster wrote:
Stuart Noble wrote:

Timothy Murphy wrote:

I think water is coming in through an old (150 year) brick wall,
which looks very pitted.
(The rain only comes through when there is also a strong wind.

Can I get a spray which will seal the wall?
Or should I apply something with a brush?



I've never found anything that really works. I've totally flooded
walls with Thomsons Waterseal and it's made virtually no difference. A
bit


Actually I've used it in these circs pretty successfully. After it was
applied, when it rained you could easily see the area of outside wall
where I'd applied it, as the brickwork stayed pale-coloured and
moisture-free whereas elsewhere it went dark as water soaked in.

I'm never quite sure whether it's a good idea to use it though, ie,
you're sealing a wall which is meant to be able to breathe.

David

The walls I've used it on could certainly breathe (and drink) quite freely