I just had an answer from Unibond, so if anyone else needs to know how to do this here is what you need - Unibond Tile on Floors Ceramic Adhesive for Asphalt Floors (20kg bag covers 8m square). You will also need to use a flexible grout with this adhesive.
I will try this at the weekend and...
I\\\'ve just renovated our dining room and want to lay a ceramic floor, and remember how hard it was to remove marley tiles in the past in another room.
The existing Marleys are firmly secured to the concrete floor below and I want to tile straight over them - which adhesive would be best...