Mongoct, I tried the jumping to check the shimmer! Very low shimmer :) Getting ready to install the floor warming cables so need to get the floor prep finished. Here is the 3/8" ply screwed down 4"oc as Bill V recommended. Now I have just realized something :( ... I have the underlayment installed and I still don't have the last joist on the far left in place yet. When we screwed the new joists to the floor we didn't have the underlayment in place. Now we need to get that last joist in there and the underlayment is in place. I added a link to the old floor discussion below. That links to the "Remodeling" forum. I have posted more detailed information on there. Its about my progress getting the floor to this point and was posted today. Here is the new joist positions, but the far left is missing the new addition: 1) So is it ok to screw through the underlayment into the joist on that last one? 2) Or should we put bridging in between the joist and the plate and toenail these short pieces into the joist and plate? I thought the principle of the layers was to help isolate them from one another. If I screw that last joist to the floor it will go through all of the layers and I will lose the layering effect, right? The reason for the underlayment going in was I had the help and I forgot about that last joist. The plumber isn't done, but he said he didn't care if the joist was there or not. Here is a link that might be useful: Adding joist to existing floor...

Based upon most of the threads on this forum, you might ask him this: "After your installation fails, will you do it the way Bill says it should have been done in the first place?" Oh, and tell him that tile installers are not allowed to cry after reading what we write about them. Actually, just ask him to bring his TCNA Handbook to your first meeting so he can show you diagrams of how he intends to do your installation. "Uh...what handbook?" Mongo

"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

If you are concerned about a possible foundation leak. I would suggest you get an inspector out first to get their opinion. While its no necessary since havent seen water. Now would be the time since you are rippin up the carpet. And after what the inspector then proceed.