Loft Chimney breast needs pointing

[melodymaker]

The chimney breast in my loft has mortar like powder, in some areas bricks are missing as well as large gaps. When I scrape away the mortar it's like dust. I am going to point it up but need to know if I need to get all of the loose dust out or not. I would have thought I would scrape 2 3rds out and spray with water before cementing?

 

[noseall]

2/3rds, ease up!

remove one third but do soak liberally with water prior to pointing.

 

[melodymaker]

Cheers. One third it is

 

[Symptoms]

mel - also, the best way to apply the water to the chimney breast is with a pump-up garden sprayer. You'll be able to direct the water accurately and without loads of splash going onto the ceiling/floor below which may cause damage; if you brushed it on you'd also get loads of dribbles & splashes.

Another advantage of using the sprayer is that it's an enclosed container; an open bucket holding the water could/is likely to get kicked over in the loft confines ... again damaged ceiling.

 

[smuudge]

what sort of concrete mix is best for pointing a chimney breast like this? Mine is in exactly the same state, pointing is pretty much turning to dust. cheers..