"I have put the blue drywall behind where the vanity will go, I'm satisfied it's not going to get that wet, but around the shower and above it, I want to tile and thought I'd use backerboard or whatever the fibrecement sheeting is called....which leads to a couple of more questions -"

"Blue" drywall...is that blueboard, or drywall typically used for veneer plaster applications? It can be finished with paper tape and joint compound, so it'll be fine in non-wet areas (wet areas being a shower or tub surround).

For shower and tub surround walls, below 72" or below the height of the shower head, you don't want to use a drywall-type product. As you mentioned either a fiber-cement (hardieboard) or a true cement board (durock or wonderboard) would be used for the wet walls. The seams get finished with thinset and mesh-type fiberglass tape.

In wet areas, above the 72" from the floor height, you can transition to a drywall-type product and paint the surface. Or continue the cement board and tile to the ceiling.

Where you transition from the cement board to the drywall board, hide the horizontal seam behind the top course of wall tile.

"1) I understand some drywall mud is suitable for tiling and some isn't, what's best, and should the backerboard stuff be mudded at all?"

This will hopefully be an all-in-one reply:

In wet areas, use cement board or fiber-cement board as the tile backer. For those seams use thinset and mesh tape.

When you tile in a wet area, use thinset to adhere the tile to the cement backer board.

In non-wet areas, the tile backer can be the items listed above, or you can go with regular drywall. Since the drywall will not be getting wet, those joints can be finished with joint compound and paper tape.

For adhering ceramic tiles in non-wet areas, you can use thinset or mastic to adhere the tiles to the drywall.

For adhering a natural stone in non-wet areas, you should use thinset, do not use mastic. Mastic can bleed through and discolor or stain the stone.

"2) Can said mud be used for a transition join between the drywall and the backerboard? Can I tape the join, or is fibreglass tape (the mesh stuff) better?"

For that transition seam you can use either; joint compound and paper tape, or thinset and joint compound.

"4) I'm (ideally) keeping the original door jamb which means it finishes more or less flush with the drywall. Around the rest of the house I've used a plain, chunky square 4"x1" trim/skirting/doorframe. I figure I have to either affix the trim *before* the tiling because I assume the tiles will butt up against them. I thought about using parchment paper or similar to protect the trim edges when tiling then remove paper and silicone seal the edge (and maybe not attempt to grout up to the edge of the trim)"

An easy way is to tack a scrap piece of wood in place where the trim will go. If your trim is 4", set the edge of the scrap piece of wood at the 4-1/8" line. Now tile right tight up against the piece of scrap wood.

When tile is set, remove the scrap piece of wood. Install your 4" trim. You should now have a very nice 1/8" gap between the edge of the tile and the trim. Caulk that gap, as wood may move seasonally and the movement would cause grout to cracks. There are color and texture (sanded vs unsanded) caulks made to match most grout colors.

"5) Am I crazy to leave the vinyl flooring when I'm doing virtually everything else? Vinyl is in good shape despite the work etc that went on around it, and it continues out into the hall unbroken so I'd have to redo a fair amount of flooring. I'd love to tile it but I figure walls are hard enough (haven't tiled a wall before) so floors might be a it much...besides, I'm thinking as long as I'm prepared to remove skirting, vanity and toilet, the floor could be redone later, if necessary....?"

That's your call. If you think you might tile down the road, then plan for it now. Think of how thick your tiled floor might be. Example, if your existing subfloor is 3/4" plywood, there is probably something like 1/4" luan over that and your vinyl is on top of that. So on top of your existing subfloor you have maybe 1/4" plus 3/16", or just under a half-inch of "flooring".

If you tile, you might need to remove all that half-inch of "flooring" and add half-inch underlayment, then either 1/8" ditra or 1/4" cement board, then your thinset and tile (1/8" plus 3/16").

So sort of worst case (and a total supposition) you'd be looking at adding 1/2" ply underlayment + 1/8" thinset + 1/4" cement board + 1/8" thinset + 3/16" floor tile, or about 1-3/16" total.

But before you add that thickness you'd be subtracting the already installed 1/4" luan and 3/16" vinyl.

1-3/16ths minus 7/16ths means the height of your finished tile floor will be 3/4" higher than the finish of your existing vinyl floor.

(I think!)

So, if you want a 1/8" gap between your wall tile and your floor tile, set the bottom edge of your bottom course of wall tile 7/8" above the height of your existing vinyl floor.

Now, all that figuring and ciphering is nothing more than a crap shoot. So what I'd recommend in a case like yours is to plan on eventually having a tiled floor, tiled walls, and a wood baseboard as a transition between the two.

If down the road you wanted a 5" tall baseboard, set a 6" tall baseboard in place now, and set the top of the baseboard level.

Tile the walls with the bottom course of wall tile sitting on top of the baseboard.

When you eventually finish your floor, remove the baseboard, tile the floor, then rip about an inch off the baseboard to make it 5" instead of 6", and it'll fit nicely.

A lot of "what if's" and made up numbers in my post, but it's a start.

Mongo

Mongo, thanks very much for your detailed reply, you pretty much covered it all! The floor is a dilemma but would be creating a whole lot more work and expense and time required, when we really need the bathroom now - the vinyl is not too bad and continues out through the laundry - and is direct on concrete (or has some sort of overlay, but no subfloor as far as I can tell, I could see concrete directly under it at the edge where it meets the shower enclosure.

You've pretty much confirmed what I thought about the transitions and the way to do the baseboard, since it's so wide rather than scrap wood I may just sacrifice some of the actual trim and just tack it on, it's pretty cheap (mdf) - I will be priming it properly with something waterproof and will probably use oil-based enamel or melamine paint on it (it'll be bright white so should be simple) as I don't want any water damage. I was worried about the edges of the vanity also, so will be raising it off the floor slightly with silicone button feet as it's an unfinished edge, and I primed/sealed the unfinished edges in case they get damp, I hate swelling particle board (vanity was fairly cheap and is the type where the porcelain sink forms the whole top, and it's not inconceivable that water could run over the edge and onto the top of the cabinet)

I get what you mean about the floor thickness, even on concrete I'd have to allow for the tile bedding etc, I will tile to the edge of the baseboard and plan to trim the bottom if I tile it. The baseboard has a slight rounded pencil edge, which I can match with a router bit.

Just one more question, if that's ok, well maybe two :)

Firstly, I will probably use a line of feature tiles (the parts I'm tiling will probably be floor to ceiling, plus a small part of the ceiling where it drops (ducting etc) as it will be over the light over the vanity which will get pretty hot so I thought perhaps a few tiles over it, this will be direct onto existing regular drywall so thinset I guess?

So I am assuming the feature tile should go up first, as a guideline to keep everything straight, I can either do a pencil line with a level (and then have the problem of it being covered by adhesive) or I can use my laser level instead...

Lastly, the question of start and finish edges, most tiling jobs I see they have a cut tile at the bottom of the wall and one at the top as well, I assume that's either so you don't end up with a sliver of a tile at one edge (which might get thicker or thinner if the wall's not plumb) or so it appears straighter since they're cut...?

I have a cheap wet tile table saw I picked up just for this job, a dremel with tile cutter and a dremel drill press rig if I need to do anything tricky, plus some of those spade-type tile bits so I figure I'm ok cutting-wise. I am going to try to keep it simple, as this is my first attempt at tiling (done most other things but this and wallpaper and I'm not much interested in wallpaper!)

Thanks again...

For tiling ceramic onto drywall in a non-wet area, you might find mastic easier to work with. It has better tack and better sag resistance than non-specialty thinsets.

As to cut tiles on a wall, sometimes the size of the baseboard or crown can be adjusted, or the thickness of the grout lines can be adjusted, or a fru fru decorative border can be added somewhere in the wall which will allow you to not have any cut tiles in the wall.

If you do need to cut a course, yes, what you want to avoid is a thin sliver of tile at the top or bottom.

A couple of examples:

If using 6" squares, if I have 15 full courses and the last course is 5", then I might cut one inch off the top course of tile and leave it at that. Or I might cut i" off the bottom course of tile and have that conform to a wavy floor, and finish the wall to the ceiling with 15 full courses of uncut tile.

If I had 15 full courses and the last course came out at 1", then instead of having that "sliver" of tile at the top of the wall, I'd only use 14 full courses. I'd take the 6" plus 1" remaining, divide that by 2, and get 3-1/2".

You could then use a 3-1/2" course at the bottom and top of the wall and the 14 full courses in between.

The "rule of thumb" is that if a cut row will be less than one-half of a tile (in this case less than 3"), then use the latter method to avoid the sliver.

It's not a necessity to do that, it depends on the tile used, your layout, the overall design, etc.

You can use that same technique vertically as well, to avoid slivers in the corners of the room. Same with floor layouts.

And yes, if you have an out-of-level floor, you want the wall tile level, so you'd cut the bottom edge of the first course of wall tile to conform to the wavy floor, and set the tile so the top edge of the first course of tile is dead level. And if doing so, it's easier to hide that cut if it's done with large tile rather than small tile.

Example, my floor is 1" out of level. If I was using 2" tile my bottom course if tile would go from a full tile to a half tile. Very noticeable.

If I was using 12" tile, my bottom course would go from a full 12" tile to an 11" tile. That's not as apparent to the eye.

When doing a wall wher the floor is not level, often tiles I'll screw a ledger board to the wall to "replace" my bottom row of wall tile. I'll then tile off that so the second and subsequent courses are deal-perfect.

I'll then remove the board and cut and fill in the bottom course of wall tile.

Mongo

I've already printed this out, you ought to teach tiling, if you don't, because that has to be about the most perfect explanation of the whys and wherefores I've seen, and I'll follow it to the letter!

So is my plan of starting with the feature tile and a laser level good or would I be better off starting at the bottom on the level if it is indeed not a level floor? I guess that eliminates more variables....

And is masonite/hardboard ok as furring or should I use strips of the cement board (assuming thickness is ok) instead? I'm not sure if the staples I'll use in the air stapler are galvanised or not, but I'm thinking once the board is nailed, the staples are redundant. I'm also thinking of using the waterproofing membrane stuff (the orange flexible sheeting) under the tiles, if you think that's a good idea.

If you intend on using the "orange membrane" ( Schulter-Kerdi) be sure to use UNMODIFIED thin set on the underside as well as on top to set the tiles. Reason is because modified thinset drys too quickly and needs air to cure fully the membrane is Not porus so it will take forever to cure. Home Depot sells Red Guard whuch is another elastic paint on membrane. Problem with that is if u pull a tile off, that can peel.