Tile Installation Questions

[dborns]

I started a new tiling job in my hall bath this week. I had to breakup the old tile, and it came up pretty easily. Now, I just have the old mortar on the floor. My first question is, can I tile over that mortar, or do I have to scrape it up? I'm hoping I can go over it with new mortar, but wanted to verify.
The second question is, the tiles are 6"x24", and it suggests to install in 33" pieces, so obviously cut into 1/3 pieces. So when I cut a piece of tile, is that middle piece trash? I'm just thinking that the ends are not going to be rounded off like the end of each uncut piece of tile. Am I incorrect in that?

 

[havasu]

First, you must scrape up the old thinset. Secondly, Depending on your layout, usually if you cut one end as a starter piece, you use the cut piece on the next row, depending on the layout. You cut it in half, you will have a running bond, like brickwork. Try cutting only 1/3rd to start, the second row, use the remaining 2/3rds piece, then the third row, use a full tile. This gives you a random look, less uniform.

 

[bud16415]

I might not be understanding here. if the tile is 6” x 24” how can you cut it to get a 33” piece.



Follow havasu’s advice and don’t put any cut ends anyplace except around the edges of the room.



Normally you measure the room and start your layout such that you don’t end up with a sliver on the other end. If you start in the middle and work out in your pattern the middle of the room can be a joint or it can be the center of a tile. One way or the other will produce the widest piece on the ends/edges. The other direction is also similar depending on what you are going for. Your old pattern was a straight bond as the tiles were just laid in rows both direction. You can also do a half bond or as suggested a third bond. Again I would measure the room and make sure whatever bond you run you don’t end up with slivers on the end.

It is pretty easy to just dry set a few rows in the bond direction and one row in the other direction to see where you are at if you don’t want to do the math.

 

[dborns]

Thanks for the replies and assistance.
Havasu, I’m not liking you much right now..... Kidding, I was pretty sure that’s the answer I’d get, that the old mortar has to come up. Any suggestions on how to do that correctly would be appreciated. I’m not sure, I’m just assuming the backer board is screwed down; that’s the way I was taught anyway.
Would wetting it down some help break the mortar up?

Also, my apologies on the 1/3 cut question. I misread the instructions.

 

[havasu]

I used an air chisel with a wide blade for my last tile job. Yep, lots of dust, lots of work. If screwed down by a backer board, you may consider ripping out the old backer board and just replacing it. More trash. But less mess. Alot has to do with the thickness at the transition to the next room. Sometimes this is a critical issue, since you don't want a tripping hazard.