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