Accessible bathroom with Curbless shower

[PC7060]

Yes, we quite often get freezing temperatures here. Sometimes as low as single low teens, although low 20’s at night is typically the worst we have to deal with for long periods.

The TDS for the Large-Format Floor Tile Mortar says it’s only rated for horizontal applications and with the following recommendations freezing conditions.

“Mix with Polymer Additive for areas subject to severe freeze/thaw conditions”

The stone will be set over a surface prepped with exterior stucco base coat with mesh reinforcement which is rated for masonry mortars.

The stone weight approx. 75 lbs each but fortunately I’m only setting four of them.

[cx]

Had to go to the MAPEI site directly and search to find that mortar, PC. Looks like one of those products made specifically for sale at Lowe's and specs read like a dumbed-down version of their Large-Format Floor & Wall Tile Mortar. Not thixotropic, not extend open time, mostly lower shear bonds, etc.

We can say we don't get no steenkin' severe freeze/thaw down here either, unless, of course, you were here last month.

Think I'd want some waterproofing (and to know what's under your stucco) and a sloped surface even though those big ol' rocks aren't much like tiles. And I think I'd toke up for some of the additive for my mortar. A little surprised you hadn't already planned for all that.

And Mrs. PC is happy to handle one end of them rocks? Or you fixin' to try that all by your onesies?

My opinion; worth price charged.

[PC7060]

Originally Posted by CX

Think I'd want some waterproofing (and to know what's under your stucco) and a sloped surface even though those big ol' rocks aren't much like tiles. And I think I'd toke up for some of the additive for my mortar.

The additive is the only thing on list that has not already been addressed.

The area where the stone is being installed is 40 year old masonry which previously had a stucco coating on side and 3/4" slate on top adhered with liquids nails.

We ground off top layer of stucco to remove old paint and such and applied a STO Primer/Adhesive-B with mesh over all surfaces. The STO was carried over the opt to fill voids and / cracks that were previously allowing water to seep into the block. The vertical surfaces then had a top coat of STO DPR finish in a color approved by Mrs. PC.



The top surface is slope to drain off water and I will make sure the stones is set to maintain the slope.

And Mrs. PC is happy to handle one end of them rocks? Or you fixin' to try that all by your onesies?

Uh, no assistance from Mrs. PC. I'm handling, cutting and setting these solo.

[cx]

Que Hombre!

I should have known you would already have dotted your I's and crossed your Ts, PC, but I just always gotta axe, eh?

[PC7060]

I been schooled a few time a’for on this! “Did you read the manufactures data sheet?”

[PC7060]

I’ve got stone related question similar to @vmcmahon recent bluestone tread posts here

The top tread of the bluestone slate on the my porch was reset a number of years before I bought the house but was set too high and didn’t bond to mortar. I’ve removed the stone and cleaned off the patch mortar to get back to original mortar.

I’d like to use Versabond LFT thinset (medium set?) to set the slate. Per the TDS, looks like meets all requirements for the application. I used the Mapie LFT medium set on the large side porch stones last year and found it easy to work and bonded well. Going with Versabond this time since it does not require additional modifier for cold climates.

Can you use the Versabond to fill the mortar joints as well?

[cx]

There is no medium bed, or medium-set tile installation method, PC, regardless what Custom wants to call their mortar. Their Versabond LFT is a LHT mortar and you'll be using it in the thin-set method.

Originally Posted by PC

Going with Versabond this time since it does not require additional modifier for cold climates.

Which MAPEI mortar required the liquid admix, PC?

I suppose a fella could use the bonding mortar as his grout if he wanted to and if it were the right color, but it's always recommended against in the industry. Exactly why, I cannot say. Would it be sufficiently durable? I dunno. Is it more porous than good cementitious grout? I dunno. Would it stand up to your freeze/thaw conditions? I dunno. Be sure to come back after a couple winters and tell us all.

My opinion; worth price charged.

[PC7060]

Originally Posted by CX

Which MAPEI mortar required the liquid admix, PC?

See post 61 on this page for the official MAPEI name along with a link to the TDS.
Edit: just checked the old bag (need to toss) and I used Versabond LFT to set those stones as well. Probably for the same reason, didn’t want to add the modifier.

Re the cement grout, I’ll have to see how it all works out. I filled on joint today for a test and will check early tomorrow am to see how it looks.

What grout type do you prefer in these application?

[cx]

Sorry, didn't consider that we already knew about that mortar, PC.

Thing is, all the manufacturers would prefer you used one of their mortars that required the addition of a liquid polymer additive when doing those more critical outdoor installations. But the Versabond might work just fine. You'll know soon enough.

For those large joints, such as with Saltillo tile installations, I've always mixed 3 sand to 1 Portland cement to use as grout, interior or exterior. Can be colored if desired, but it might be easier just to find one of the newer sanded grouts that says it can be used in joints the size you have. Might make a better match to what you've got. Or not.

My opinion; worth price charged.

[PC7060]

Thanks for the information, CX. I cleaned all joint in preparation for the masonry grout.

The current stuff looks like standard type S mortar which has similar proportions to your mix with the substitution of lime for portion of the Portland cement; about 2-1-8 Portland/lime/sand combo. I’m drawing a blank on the benefit of lime but I’m sure someone here knows!.

[cx]

For your grout, no advantage at all, far as I'm concerned. Would make your grout cure softer and more porous, which is not what you want in your application.

My opinion; worth price charged.

[Tiger Mountain Tile Inc]

PC, I think you want a mortar that meets A118.15 which Versabond LFT doesn't.

Outdoors and in the weather? If it were me, and I had to choose CBP brand, I'd go with Megaflex and Prism grout. Megalite would be fine too.

[PC7060]

Thanks James, appreciate the advice.

[PC7060]

Hello again, @johnbridge pros!
I’m finally starting to set tile in two large shower added as part of my 7+ year 1920’s house renovation project. I’m using a simple 4x16 subway on wall over USG foamboard. The tiles aren’t super flat so I’m planning on using a 1/4 x 3/8 notch trowel with Versabond thinset. I’ll check the coverage for the first row or so and adjust from there as required.

The first shower is a standard step in curb type; the second is the curbless added as part of the accessible 1st floor suite. Getting old is not for the weak!

[cx]

Where ever did you find USG foamboard, PC? Or did you start these showers some years ago? Or maybe that's still being made?

I'm not seeing a question for us.

Wait 'till you get into the group that's actually getting old. You ain't seen nothing yet!