1950's Bathroom Remodel [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


View Full Version : 1950's Bathroom Remodel

01-10-2017, 02:08 PM
Hi All,

I haven't been around these parts in a long time because I haven't had a tile job in awhile, but I guess I'm glutton for punishment because I bought a 60-year old house that needs work. I have the main floor bathroom down to studs, and I'm just finalizing some things that go behind the studs before I start the finish work. My main question is regarding the tub surround. I bought a real basic metal tub to go in the same spot as the old cast iron tub, but I'm tiling the surround. I'm using 12" x 24" tiles with an accent ribbon around the top. I also want to add a niche right in the middle of the back wall. I plan on framing it out to take a full 12" x 24" tile across the back. The accent ribbon will run above the niche. Here's where my questions come in:

1 - I will be mating the left wall with greenboard so I'm using 1/2" hardibacker because it's the same thickness as the greenboard. I don't necessarily have to use 1/2" backer for the back wall or right side wall due to the layout, but is it still recommended to use 1/2" for stiffness? My studs are 16" oc.

2 - Also, my preferred method is to use a single piece of clear plastic around the entire area before attaching the CBU, but what do I do about the niche? Do I just make a few cuts in the plastic and accept that the edges of the niche aren't going to have a water-proof membrane behind it? Do I cut an additional piece and lay it out inside the niche area making sure the bottom of the additional piece falls over top of the larger piece?

3 - Lastly, in my last shower build I didn't actually screw down CBU to the bottom surface of the niche because I was paranoid about water leaking down into the wood. Instead I used the vertical CBU pieces to act as a form and poured in some mortar to fill the hole. Let it set up for a day, then stuck tile to it with thinset.

4 - Bonus question: can I use the same grade of thinset for the wall tiles of the tub surround and the floor tiles? Menards has several grades of thinset depending on how much flexibility I need. Any idea how much flexibility I should look for? The most expensive bags are actually quite expensive.

Sponsored Links

01-10-2017, 02:27 PM
I should've added this is a shower/tub surround.

Also, I see Lowe's is marketing thinset for large tiles that go on walls at about $30 a bag vs. regular modified thinset for average sized tiles at $15 a bag. Is the $30 bag worth it for my large tiles or is it just an advertising opportunity because they know 12" x 24" tiles are popular now?

01-13-2017, 06:52 AM
Anybody out there?

Houston Remodeler
01-13-2017, 07:58 AM

Sorry for the delay. My day job got in the way. :yo:

1- 1/2 in is the bare minimum for wall applications

2- Ah, the conundrum of this system. You can bow out the plastic OR use a surface applied membrane in that area overlapping the sheet plastic a fair amount

3- Ah the conundrum of this system and why we abandoned it. Fasteners are required. If you are happy with your installation, its your house. There are no tile police.

4A- What do you mean flexibility?
4B- What do you consider expensive?

5- Which specific thinsets are you referring to ?

01-13-2017, 08:36 AM
By flexibility I meant the amount of polymer in the thinset that allows it to flex without cracking. The more expensive ones tend to have more polymer, but they seem to be meant for extreme applications, and I'm wondering if a basic tub surround needs anything more than just normal modified thinset.

Here's my options for thinset:










John Bridge
01-13-2017, 10:20 AM
I think I would use the same board all the way around the surround and use a liquid waterproofer over the whole thing, i.e., RedGard, Aqua-Defense, Hydro Ban. Non membrane behind the board. For the board, Wonder Board, PermaBase or Durock beats out Hardi-backer. Hardi- is way too thirsty. :)

01-18-2017, 10:01 AM
Does the tile stick to the waterproofing membrane all that well? Or would I be expected to then use something like Schluter?

The problem is I already have the materials ready to go and no good ability to transport materials anymore.

Does it matter much if the CBU absorbs a lot of water since there's going to be a waterproof membrane on either side of it? This is why I tend to like the idea of putting up plastic behind everything knowing full well that most things will absorb at least some amount of water, but at least it will never touch the wood. I worry about a surface membrane because if water finds a way through it's going to find the wood.

01-18-2017, 10:23 AM
It does matter that the CBU soaks up a lot of water, because your thin-set could skin over too quickly and/or not end up with enough moisture in it to create a good bond.

The surface membranes are quite good and very user friendly. I took a 6" x 6" square of Kerdi, cut in to the middle from a corner and curved it to form a cone. I filled it with water and just held it, nothing at the seam and no water leaked out. I then just put scotch tape at the seam and put the cone in a smaller cup so it would catch any water that came out. After several hours, no water was in the cup. I was sold. The stuff is quite good and easy to use, and has a whole set of instructions and details for every condition (just about) you could possibly imagine. I will admit I was at first a little shocked at the price, but knowing my shower isn't going to leak helps me sleep at night.

Also, the Menard's thinset, in my experience, is typically junk. I regularly find bags that what water spots from sitting out in the rain, bags whose date codes are 9 months old or more. People return unused thinset from a project they started last year and Menards puts those bags right back in circulation. I stopped going there after awhile.

My nearby Tile shop will not typically accept returns for products like grout or thinset after 30 days, and for good reason. It has a shelf life. I recommend finding a quality tile shop near you with good products. Of course YMMV.