You couldn't tile directly over a plywood sub-floor because over time, the wood will be expanding. There are products you can use in between the plywood and tiles to keep them in place such as cement backer board.
not advised, wood expands too much
No, plywood alone is not strong enough for ceramic tile. These floors require a very sturdy subfloor at least 1 1/4" thick before the tile. This requires either using cement board or a pored mudbed.
You would be better of removing the plywood floor completely - and tiling over the original surface.
If it's plywood, it's probably at least 3/4 real ply as opposed to 3/4 composite, what I call Japanese wood. However, I wouldn't use ply under ceramic tile. I would use at the very least the material called Hardi-Board. Ask about it at the hardware store.
hardwood or vinyl . tile on a raised foundation will always crack in the grout lines
You couldn't tile directly over a plywood sub-floor because over time, the wood will be expanding. There are products you can use in between the plywood and tiles to keep them in place such as cement backer board.
not advised, wood expands too much
No, plywood alone is not strong enough for ceramic tile. These floors require a very sturdy subfloor at least 1 1/4" thick before the tile. This requires either using cement board or a pored mudbed.
You would be better of removing the plywood floor completely - and tiling over the original surface.
Improper installation. You must install cement board over the sub floor before you tile. If the tile was glued to plywood which is not waterproof, the plywood will absorb moisture which will cause the grout to crack and deteriorate
Plywood is the best choice between these two. Particle board can swell if water gets to it. You would be better off if you use a tile backer board. Concrete based or a fiber type. They are made for this application.
I don't recommend it. The plywood is flexible and bends over time. Cover the plywood with Hardi Backer board first. Available in the tile department at Lowe's and Home Depot. Get the right screws for it. It's easy to install, comes in manageable size of 3 feet by 5 feet. Well worth the time, effort and money to make sure your tile job lasts.
You CAN place tile over tile, but saying you can put tile over tile is like saying you CAN jump off of a bridge. It's just simply not a good idea. It can cause air pockets to be created under the tile laid on top, which can lead to cracked tiles if anything is dropped on them or sometimes simply by walking on them. It's worth the time to go ahead and strip the tile off of the floor before laying any new tile.
You're mum got laid last night.
Tile does not have to be laid the same way in two different rooms. Having said that, if the two rooms join each other the tile really should be laid in the same fashion in both to avoid looking esthetically incorrect.
Exterior grade plywood is not waterproof and is not meant to be used as a base for tile in exterior applications. Exterior tile needs to have a cementious type base which will not swell or deteriorate when wet.