Hi Peter Never subscribed to anything on you tube and been an internet user for 20 years :-) great channel. I an an DIY'er rennovating my own cellar - just unblocked a deliberately blocked airbrick...now scarping goodness knws what off the walls looks like a mixture of white wahs and something else not sure what... plan to re-white wash and ventilate well - any other top tips.. this part of cellar is 'underground' by about 6 feet - the footpath at the side of the house runs along eye level when in cellar - 1911 red brick Manchester semi... thanks