sealing a chimney crown

[vernerbongo2]

Hello

I have damp in a bedroom wall with an external chimney breast behind it.
A friend suggested it could be coming in through the chimney crown.
Took a look & it seems solid but looks damp.

I want to seal it with a coat of something but what?

Thanks

 

[pinenot]

It's also likely to be condensation as much as anything, so seal it by all means but also look at providing ventilation to the stack.
Any good brick/concrete sealer will suffice, check them out at your local builders merchants...pinenot

 

[vernerbongo2]

Definitely not condensation!

Never had it until now & wall patchy with efflorescenses & bubbling paint.

Other than the likes of Thompsons water seal which I've found useless, what else is there?

I've seen actual crown seal but it seems to be American, so not available here.
Apparently your supposed to use something that lets the chimney breath.

Stack is in use also!

 

[joe-90]

It's defo condensation.