The roof on my garden shed (7'x7') is in pretty good condition but I suspect it is one of those cement asbestos ones and although the advice is to leave it alone if it is in good condition, I would like it replaced. Does anyone know of a reliable roofer covering West London and the cost involved in replacing the roof and disposing of the old roof safely? I would also like to replace the metal guttering at the same time, front and back. The house is an average 3 bed terrace house.