Restoration of marble floor

I am seeking out any information on processes to lift and relay
ceramic and stone tiles in a Sydney church.  The floor has sunk in
several places and attempts to support it by filling the area below
the floor with sand has failed.  A preliminary investigation has
revealed that the tiles are laid on and well adhered to a thin
cement layer which covers one course of bricks, and below which is
sand and clay.  There are damp and salt problems and a considerable
amount of cracking.  The proposed strategy is to lift the tiles and
lay a suitable substrate, a membrane and then the tiles.  The total
floor area is approximately 1000 sqm.  Does anyone have first hand
experience at this or know of any relevant publications?

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                  Conservation DistList Instance 11:79
                 Distributed: Wednesday, March 25, 1998
                       Message Id: cdl-11-79-014
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