In article ,
Jake wrote:
Yes, it definitely has cavity walls. I've had to replace some bricks
in it.

In other words, the wall consists totally of stretcher bricks with no
headers? Ie all the bricks are lengthwise with none end on?

Yes, there is an issue with rainwater gathering on the pavement
outside to some extent, but I can't do much about that.

All the true cavity walls I've ever seen have a damp proof course. If you
can't see it for some reason to be sure, then that needs to be addressed
first.

Anyone got an answer to my original question?

On its own, a silicone damp course won't cure the problem. It has to be
combined with a waterproof re-plastering of the inside. Which beggars the
question as to whether the silicone does anything worthwhile at all.

--
*42.7% of statistics are made up. Sorry, that should read 47.2% *

Dave Plowman London SW
To e-mail, change noise into sound.