I am installing underfloor heating in my bathroom, on top of a new, 10mm thick thermal underlay.
I am going to instal a back to wall WC pan on a square sheet of 12mm external grade plywood to bring it more or less level with the area containing the heating elements, and then tile the entire room, cutting the tiles to fit round the WC.
I would be very grateful for advice on whether it would be better to tile all the floor and then fit the pan on top of the tiles.
Should the plywood be sealed, and if so, with what? A PVA solution?