Hello I have previously had loadsa problems with dumb builders browning over removed chimney patches (on the internal side of an outside wall ) and using the same black soot soaked crappy bricks which draw in like mad any rainwater and moisture from outside and makes big patches since they used a gypsum based plaster and not sand cement.
Anyway now there's one chimney left which I intend to do myself (I've bricked it up using only bricks with no trace of soot or carbon) and plan to use 2 coats of 3:1 sharp sand cement with waterproof (rendamix) I am hoping this will be enough to stop any hygroscopic salt problems
As an extra measure should I coat all the brickwork with a water/pva mix will that "seal the brickwork" in any way, normally I would just damp bricks with water before applying render
Also between coats and before the final finish plaster coat should I pva the coats or just damp down with water?
Oh and next time as an extra precaution could I paint some bitumen paint on the internal layer of the external layer bricks (solid cavity wall) to restrict any moisture coming into the internal brickwork has anyone else done this?
Any help greatly appreciated
Anyway now there's one chimney left which I intend to do myself (I've bricked it up using only bricks with no trace of soot or carbon) and plan to use 2 coats of 3:1 sharp sand cement with waterproof (rendamix) I am hoping this will be enough to stop any hygroscopic salt problems
As an extra measure should I coat all the brickwork with a water/pva mix will that "seal the brickwork" in any way, normally I would just damp bricks with water before applying render
Also between coats and before the final finish plaster coat should I pva the coats or just damp down with water?
Oh and next time as an extra precaution could I paint some bitumen paint on the internal layer of the external layer bricks (solid cavity wall) to restrict any moisture coming into the internal brickwork has anyone else done this?
Any help greatly appreciated