We generally recommend that the underlayment be removed because the subfloor may not be adequate to support tile. However, if your existing vinyl floor was installed over an adequate subfloor using a full spread installation method then yes, it can be done if you use the proper installation products.

Hardwood flooring expands and contracts due to changes in temperature and relative humidity. Having adequate levels of humidity in the home will help minimize the shrinkage of your floors during the heating months.

One of the rubs against ceramic tile is that it is cold and hard. There are floor heating systems available to make your floor more comfortable to the touch, but in terms of hardness, yes, ceramic is much like hardwood in that it doesn’t have much give. If you want something that has more cushion to it, perhaps you should consider a floating floor.