These are the four basic steps for cleaning up smoke affected areas on brick or stonework:

1. Remove any debris and scrape off any stuck on residue like burnt plastics, etc. Any burn plastic residues may have to be removed with special solvents at the end of the job. Do not try to remove all of this at this stage.
2. Apply World's Best Detergent at approximate dilution of 1:10 water and apply by broom to small areas like 2 or 3 sq/m agitating with the broom as you apply. Do not allow the the detergent to dry out. Rinse off with a pressure washer (a hot one, if possible).
3. Any hard burnt or resistant areas that become revealed can be treated with Bare Brick Stone and Masonry Graffiti Remover applied three times and three minute intervals then high pressure water rinsed off.
4. Extremely hard burnt areas not responding to the first treatments as described will often respond perfectly by applying Feltpen Fadeout as thickly as possible making sure it is left for as long as possible. We leave it overnight if it is safe to do so.

Things to be aware of...

Any brickwork that has suffered such intense heat that it has cracked or the mortar joints have turned red/brown will never respond to any treatment within that area. The brickwork may have to be replaced.

Burnt plastics often respond to Methylene Chloride solvent type paint removers like Polystrippa. Please choose to use products like these at your own risk.

Interior surfaces such as plastered walls, paintwork can be treated as instruction #2 but by using a much weaker detergent mixture (1:20 water). Any smoke affected paintwork nearly always requires repainting. 

An areas failing to respond to any of the above may respond better to acidic detergents as the burnt by product residues may be different compounds than expected. 

These instructions are only to be used as a guide only and any job must be thoroughly investigated as to the sustainability of using such techniques BEFORE commencing any work.