We were able to get all the Hardibacker mortared in place. It is very important to mortar the backer into place if you are going to tile to reduce the amount of movement on the underlayment to keep things from cracking or popping. We used a 1/4" notched trowel for this job -- and as it turned out, we would be using the same size for our tiles. You have to be careful with mortar as once you get it mixed, you have a very limited time to work with it. It is very important to be sure to wipe down the mortaring surface with a wet sponge before laying out the mortar for two reasons: 1. all loose material/dust needs to be removed; 2. mortar need to be moist to cure properly and you want to be sure that the surface that you are using the mortar on isn't going to suck the moisture out of the mortar. Cement board is thirsty so we wiped more water on the cement board than we did the plywood. We laid out the mortar one sheet's worth at a time. Then using Backer-On screws (special screws made just for the Hardibacker product - they go through like butter and even countersink themselves!) that were just long enough to go through the Hardibacker, mortar, and then sink nearly but not all the way through the 3/4" plywood, we screwed the board down every 8" while the mortar was still wet. We read that we could walk on it right away but we still had to wait at least 24 hours before tiling.
We used the time to try to figure out a starting point for tiling. We also needed to make sure that we had enough tiles for the job, so we laid out the whole room.Ooooo, ah! That's what it will look like when it is all finished! Isn't it lovely?
Oh, well. Enough dreaming.
We tried a couple of different layouts but ultimately decided that since the doorway was going to be the most prominent part of the room, we would start there. We squared up a line of tiles to the threshold and adjusted the layout from side to side until we were sure that we would not end up with funky or small cuts somewhere in the room where it would matter.
As we pulled up the laid-out tiles to make room for mortar, we drew outlines of some of the sheets of tile to give us some lines to go by. This was recommended by all the tiling sites. Funny thing is, they don't tell you how you are supposed to deal with the fact that the mortar most effectively covers any and all lines that you may have drawn!
Even though I am pretty good at eyeing up things, we used spacers. It helped to keep tiles from shifting when we laid new ones in and it gave us piece of mind that our tiles were in the right spot in our layout. Although many packages say that you can leave the spacers in place and grout over them, we both decided that this did not sound like the best way to do it as the grout would not stick well to plastic spacers. So, we put the spacers on end in order to be able to pull them up later. This is called "tombstone style".
We mixed small batches of mortar. It should have the consistency of cake batter. We used the 1/4" notched trowel to lay a bed of mortar to set the tiles in. First you kind of scrape a layer of the mortar into an area using the flat side of the trowel, then you get a good amount of mortar to notch in the area. The tiles should be wiggled into the mortar to ensure good contact.Once the mortar is firm, take a small plastic putty knife to scratch the mortar out of the grout lines and then wipe mortar of the surface of the tiles with a damp rag. The mortar must be removed before it hardens or you will be trying to chip it out with a chisel! Depending on your tile type, you might be able to wait until the next day to wipe the mortar off the tile face.
This is as far as we got this weekend. We spent quite a few hours Saturday hunting down the right size tile spacers, and Sunday we went to our neighbors to replace her kitchen faucet while she was out visiting her parents. She's in for a nice surprise when she gets home and sees her brand new, beautiful faucet where the old, corroded, leaky one was! 
:O
I admire your bathroom building skill!
it does look nice.
Alot of work though.. i didn't know about all that stuff..
and again i was confused with some of the words used in your post... specially "mortar"...
what in the world?
i've heard this word on video games, and it usually refers to a kind of missile launching thing... or is that morter?
hahaha i dont know..
from what i can gather it's something you mix up and put on something else.. haha :P
and dries up very quickly hehehe...
i finished what i had to do here (at work) so i'm freee to wonder around the web for a while..
keep up the good job!
and umm..
that's it
Leon, yes, mortar is also an explosive that you launch in battle; but this kind of mortar is actually a cement that sticks things together -- specifically in our case it sticks the tiles to the floor.
You've inspired me to start a backyard project...building a mini-patio with planter...Um,so far I've dug a trench. :)
Once again, I'm so impressed with your DIY skills!
I just read Leon's comment- :D ! I remember when I first heard "mortar" for an explosive...I was confused wondering why people used explosives to hold bricks together.
Shannon, I'm finally utilizing all those years of watching HGTV while renting ;) Who says that TV isn't educational?
Wow, I'm blown away with your mortar skills!
Sierrabella, bwhaahahaha!! ;))
It's not easy working with small tiles like those but it looks like the end project will look good. Worth all the hassle in the end.
Cheshire Tiler, welcome to my blog! It does look great. I can't believe that we waited so long to do it. And the tile isn't any colder to the feet than the vinyl that was in there before it.
I have to confess, it has been 18 months since we started this project and we aren't completely finished with it yet. It took us about a month to get it just about done, and then as is our way -- we left a little undone for a later date. Maybe this spring.