A Yes, Loose lay flooring is a special structure of LVT flooring , it is 100% water proofand fire proof, The raw material of LVT flooring is combined with  PVC resin and inorganic stone powder, they are all water proof and fire proof material.

A If the existing ceramic tiles glossy surface and the sub-ground is quite flat, you can install loose lay flooring directely.
If the existing tiles is embossment or slate surface texture, you have to remove it and repare the sub-ground self-leveling treatment.

A No, Underlayment is not required for loose lay floor installation.

A No, Glue is not neccesary for loose lay installation, Loose lay vinyl flooring has special bottom layer which is very soft and easy to close fit the sub-ground. But we suggest you can use some glue at the door place to secure the stability of the loose pay flooring where is very traffic close the door.

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