Bathroom Remodel - Down to the studs and joists

[HouseOfJoe]

Need some niche layout advice, please. So I've covered the back of the niche with my mosaic. I'm going to line the horizontal and vertical sides of the niche with the shower wall tile, then picture frame the niche with bullnose (covering the edge of the side tiles inside the niche with the bullnose).

I'll miter the bullnose, but since I'm doing that, is there any need to miter the inside pieces? I don't want grout joints in the corners of the niche, do I?

[ss3964spd]

You do want grout joints in the corners. You can fill them with actual grout or with silicone.

If the BN will be covering the raw edges of the horizontal and vertical tile I wouldn't bother mitering them, you'll not see the miters.

FWIW, I did not use any silicone for either of the two niches I've installed, grouted them both with SL Epoxy. No cracks at all, and one has been installed for 13 years. I think this is similar to what you're tying to do, but my layout of this one isn't so hot.

[HouseOfJoe]

Thanks, Dan. Yeah, what you did there is pretty much where I'm heading.

I realized after I made the post that since the mitered bullnose will have a grout line on the face of the wall, it makes sense to simply carry that grout line into the corner of the niche.

[HouseOfJoe]

So I got a piece of quartz to top my curb. I’ve heard that you can set it with thinset, but I’ve also heard many quartz/granite guys use silicone. Anybody got an opinion?

[ss3964spd]

Nooooo, I'd not use silicone to set that curb top, Joe, it is too flexible even after cured. Thinset mortar is whatcha wanna use. Maybe scuff up the back of the curb with some 60 grit.

[HouseOfJoe]

So I just bought the 7 inch harbor freight diamondback saw today and started doing some cutting and with this stock blade I’m getting a variance of about a 16th of an inch over 24 inches. putting a speed square on the table and running it by the blade seems like it’s pretty darn close but the table has just a whisker of a rock to it so I’m wondering if that might be the culprit.

I also have a virtually new glass tile/mosaic blade, I’m thinking about swapping blades and seeing if that makes it any better. Any reason I can’t use that blade on porcelain?

[smifwal]

Might be that you are pushing the tile through too fast and the blade is flexing with the pressure

[HouseOfJoe]

Could be, Shawn. I’ll keep an eye on that. Weird thing, I broke it down to clean it and when I put it back together the tiny wiggle the tray had seems to be gone. So we’ll see what tomorrow brings.

Still curious if anyone has an opinion on whether I can use the mosaic blade on porcelain and if anybody thinks that that blade might be better than the stock blade that comes with the saw. I can’t really imagine why it wouldn’t work.

[cx]

Only one way to find out, Joe.

Worst case the glass blade clogs up a little faster when cutting the softer porcelain.

My opinion; worth price charged.

[HouseOfJoe]

So for the wire lathe that goes down on the plywood that the deck mud goes over, is there a particular kind/type/size that I should be getting? Seems like a silly question, but I'm not seeing obvious choices that look right in the big box store web sites.

Also, on the paper that goes down first, is rosin paper acceptable? I've still got a big chunk of that from when I did my floors in my basement.

Thanks!

[cx]

Not a silly question at all, Joe. The industry has a spec for that. What you want is an expanded metal lath with a weight if 2.5 pounds per square yard. Should be available at your local home center. You may encounter 1.75-pound lath and for a shower floor I would not hesitate to use that. You prefer it to be galvanized, and that's usually what you'll find these days.

Whatever you find, wear gloves from the fist time you lay eyes on it until you have it covered with mortar. You will shed some blood at some point, but you can reduce the number of openings by wearing heavy gloves. And long sleeve shirts.

Rosin paper would not be a good cleavage membrane. The purpose of the membrane is to keep the plywood from sucking moisture out of the mortar and rosin paper would actually be worse than the plywood. You need something like roofing felt or polyethylene sheeting. Doesn't need to be pretty. Couple large garbage bags or old shower curtain or similar would work fine. You won't find those in the industry standards, but they'll work just fine.

Once you've placed your mortar, I recommend you cover the final product with polyethylene sheeting until you're ready to install your Kerdi.

My opinion; worth price charged.

[HouseOfJoe]

So I made a boo-boo. When I mounted the bullnose on this vertical face I made it a bit too proud of the surface of the mosaic. The only solution I can think of is to place another level of mosaic tile on top of the existing mosaic. Including whatever I use for adhesive that will bring the surface of the mosaic just a hair proud of the bullnose, which I think will look better than what this looks like.

I’m looking for suggestions on what adhesive I should use. Regular thinset? Or something else?

[ss3964spd]

Not sure there are a lot of options, Joe, but I think I'd fill with modified mortar then skim it off with a blade. You'd want the mortar to fill in all the low spots around the stones then let it dry so you have a flat surface to prevent the new stones from trying to tip into the voids. After, the faces of many of those stones will be exposed so maybe coating it all with a primer before installing the new stones with mortar will work.

[HouseOfJoe]

I guess my main question is will modified thinset work to attach a new layer of mosaic stone to this existing layer. This is a vertical, basically dry location. I’ll be placing it by hand, stone by stone, so I’m not too concerned about the subsurface as I think I can compensate for that on the fly. I’m just looking for a definitive answer on whether modified thinset will stick tile to tile or should I use another product?

[ss3964spd]

I believe coating the existing mosaic with a suitable primer, such as one specifically for installing tile over existing tile, then using a thinset mortar like Versabond to set the new mosaic would do the trick.

If you opt the the primer double check what kind of mortar is recommended for it.