New to Saltillo

[Charash1414]

I have been referred to a lady who had saltillo tile installed on her patio here in Atlanta, Georgia. There are significant problems with the installation. I only know about the efflorescence, but apparently there are more issues because she wants it taken out and re-installed. I will most likely pass on the job because of my lack of experience, though as a experienced interior tile setter, I'm curious if this is something I should consider. Here are my questions:

1. 3 to 1 portland to fine masonry sand for the grout? Any concerns regarding freeze/thaw cycles both during and after the cure period?

2. Tips to avoid efflorescence? Mapei AquaDefense the concrete slab? Are there any uncoupling membranes approved for exterior use? I know Schluter backed out of that area. Anything else?

3. Special considerations around shrinkage cracks?

4. Recommended sealer? I've read you can polyurethane them???

Thank you in advance!!!

[cx]

Might be helpful if you'd add that geographic location to your User Profile.

1. That would be a really rich grout mix and I don't think it would work well. A 1 to 3 mix of your described materials would be far more useful and what we've used for Saltillo installations for years.

2. Is the substrate properly sloped away from the structure? A waterproofing membrane might be useful. I think you'll find many of the direct bonded waterproofing membranes out there, including your AquaDefense, are indicated for exterior use.

3. Product manufacturer's instructions should detail how they want you to teat such areas.

4. I don't have a recommendation for an exterior sealer for Saltillo, but I don't think I'd wanna use a polyurethane in that application.

My opinion; worth price charged.

[Lazarus]

Done a number of these installs. You need to soak the tiles...or at least water them down a good bit. They tend to be cupped and require a LOT of morter under them to totally "bed" them on the substrate. I have only set them on a concrete slab, so I can't comment on a plywood or other base.

[cx]

Laz, if you're using the thinset method of setting those tiles there is no reason you need to soak them.

[John Bridge]

Well, I guess everyone, including me, has their own way of doing Saltillo. I haven't done it for at least 20 years. We used to always hose the tiles and drain them in the driveway before installation. It does two things: it puts moisture into the tile body and keeps it from sucking the juice out of your setting material; and it washes away some of the loose grit that's always present on bottoms of the tiles.

As to whether they should be used outdoors (sealed or not) in any climate except the desert, I would recommend against it.

[speed51133]

https://en.wikipedia.org/wiki/Saltillo_tile

found this interesting

[Lazarus]

I agree, John. When I said "soak," I meant wet them down and let them drain. Those puppies tend to be pretty thirsty.......

[Davy]

We use to install nothing but Saltillo and we always soaked them in large mud tubs. Then we would drain them for maybe 30 minutes, then set them. The soaking helped on what John and Laz mentioned but also helped when time to grout. Dry Saltillo will suck the moisture right out of your grout and turn it to powder. We usually tried to grout the tiles the next day while there was still moisture in them. If you wait too long, like 3-4 days then it would take a lot of spraying to get them wet again. Some folks freak out when you drag your water hose in their house.

We use to mix our own grout using screened sand and portland cement (3 to 1). We would mix a whole wheelbarrow of grout at a time and dump it out on the floor, then push it around using a 24 inch squeegee. If the tile had just the right amount of moisture in it, it would wash up real nice. Sometimes we would drag a beach towel over it to clean off the grout. Fun times.

[Lazarus]

Classic technique, Davy......

[cx]

Yeah, Davy, I learned the wait several days and then bring the garden hose in and hose it all down before grouting. And we use the same formula for our grout, but we added chocolate concrete stain to the mix, which dulled the gray to a more brown color. We mixed our grout in an electric barrel mixer.

And I agree with everything you said except the part about "Fun times."

[fogtown]

Decades ago I did a number of floors with Saltillo, some outside but under a roof. I don't think I'd use it in a freezing area- it's absorbtive and weak, there are stronger tiles that look similar. That said I love the look and feel for some installations and I think with proper detailing (drainage, sealing) it could be done in GA. We'd back butter heavily to fill the cup on the bottom and once I ground my own deep notched trowel to get large ridges for adjustment . Some lots had so much variation in width we'd use an 1- 1.5" grout line. Most were sealed with water base Glaze'N Seal but one job was used motor oil and paraffin for an antique look, another was 1/3 linseed oil/beeswax/turpentine. But modern sealers would hold up better! Sometimes a high percentage of the tiles had dog, cat or chicken footprints. On one huge whole house grout job our assistant mixed up the sacks and dumped a mixer load of thinset mortar instead of grout - "fun times"..

[Davy]

We did use cement coloring in our grout a few times but the company we worked for had a finishing crew that would usually stain the tiles and grout brown. So gray was fine on most jobs. They acid washed the floor about 10 days after grouting to remove efflorescence. After another 7-10 days they would stain and seal it. I can't remember for sure but I think the stain might have been mixed in with the sealer.

Dog prints in the tiles were wanted by some folks, but not always. One homeowner I remember was excited about dog prints. We had enough to start at the front door and place them so it looked like a dog went thru the dining room and into the kitchen.