Chimney breast removed, sooty brickwork

by Rory
(Brighton, uk)

Hi Paul,
We removed an old chimney breast and so the surface to prepare is broken brickwork but with some burnt sooty channels. Any tips on preparation for this would be very gratefully received. Would a sand:cement scratch coat be a good starting point? Or is bonding coat a good start. Love the website.
Thanks

Answer
Hi Rory,
Before plastering - you must apply a good coat or two of diluted PVA. Otherwise the soot will bleed through the plaster and appear on the decorated surface for evermore.
Sand/cement is good to use as it also adds mpre protection to seal the soot in. However after applying PVA - there will be no suction, so you may have to apply a scratch coat - (properly scratched - to provide a key for the next coat). This will then give you some suction for the final sand/cement base coat to be applied and easily flattened.

Paul