I am in the middle of renovating a Victorian property dated around 1880. There are seven fireplaces, all almost perfectly preserved, including the hearth, surrounds, tiles and cast iron 'bits'. At the top there is a hinged sheet of metal a couple of which are broken. When I opened these, in most cases a bucket full of dust and the occasional half a brick fell onto the hearth, presumably from where the previous owner had simply left them.
I would like to clean the existing fireplaces, including all the items set out above, but not use the fireplaces. To do this, what advice can you give in terms of blocking off the chimney which protects the chimney itself and avoids potential damp problems (which are prevalent elsewhere in the property) and ensures that I can enjoy these well preserved fireplaces?