Wetwalls

You may find dilute PVA to be a better product to inject than plaster - easier as well. I would have thought you'd need the plaster reasonably dry first.

Rob Graham

The plaster is directly onto the brick

Internal but plastered onto the brick

Loadsa damp :( But it *is* drying out

Hadn't thought of that. It was actually a liquified polyfilla type filler I used.

I intend to wait a couple of weeks.

I was more concerned about whether the damp may have caused a chemical change in the plaster that would require it to be renewed

I would have expected that.

Well we have never had any up to now and that only because the guttering was damaged by the recent heavy snowfall

No salt. What was loose and crumbly I've cleared off. The rest has ahollow sound which means it isn't adhering to the brickwork. Provided the plaster structure is sound then the injection of a thin coat into the plaster to wick it's way through will cure hold it

Well I have gouged out all the loose stuff and the rest seems fairly solid. It's an area of about 2 sq M.

You might want to think about a waterproof sand and cement layer direct to the masonary as a scratch coat. It's very tempting to spread hardcoat plaster on I know as its' so easy, the downside is that if damp penetrates the wall the plaster will act as a sponge. a waterproof render coat will stop it.

AJ