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