Sanded or non-sanded grout?

I'm laying tile in my bathroom on Thursday. I'm not what you would call savvy with tile.

Anyway, prep is all done. I stripped the original floor down to sub, repaired some tongue and groove that was iffy. Then I laid 1/2" ply (screwed on a 6" grid), then 1/4-1/4-1/4" flexbond thinset, then 1/2" hardiebacker screwed down on a 5" grid. I left seams at 1/8" and taped and mudded them as well. I even marked my floor joists and every few screws I used a 3" to tie the whole thing into the framing. Anyway, I feel confident that its properly prepped.

Here's the question. I'm told that non-sanded grout is for up to 1/8" spacing. More than 1/8" I should use sanded. Mine is 3/16" but I don't want to use sanded because of the super-glossy glazed finish. They're actually pool tile.

Can I use non-sanded? What is the difference? Will I have cracking with non-sanded? I don't get the mechanics of why one would use sanded vs non-sanded.

associated photos (hotlinked AND clickable, of course)

repaired T&G and first section of ply

two pieces of hardie down, mud laid for the third (only two seams in the whole room)

finished hardie, seams taped and mudded

Wait, you're going with a glossy tile on a bathroom floor?

I'm not a tile expert, but I have done a bathroom and it came out looking great. Tiles sold for use on floors generally have a somewhat matte finish, whereas wall tiles can be super glossy. A super glossy tile would also be super slippery when wet.

If you've already considered this, then please disregard, but I felt I should at least mention it.

I would follow the recommendation based on joint width regarding sanded vs. non-sanded grout, unless you have a strong objection to the sanded, visually.

Oh, forgot to mention (in case its important): The tile is on a mosaic backing. Here is a photo of a sample. The actual 12x12" mat has 25 tiles each, so the tiles are about 2.5" square.

1988RedT2 wrote: I'm not a tile expert, but I have done a bathroom and it came out looking great. Tiles sold for use on floors generally have a somewhat matte finish, whereas wall tiles can be super glossy. A super glossy tile would also be super slippery when wet. If you've already considered this, then please disregard, but I felt I should at least mention it.

I don't know how its done, but this is marketed as OSHA-safe for commercial use around swimming pools. I guess they've already thought of it somehow.

And I've never been on any tile that isn't snotty when wet, but I appreciate the heads-up. I guess we'll find out. I wonder if its size has something to do with it. Small tiles with frequent grout lines instead of large spans of just glossy tile? I dunno.

Sanded as it will crack in a seam that wide.

Ditto the slick issue.

That looks like the tile I put on my pool steps and I had to remove it after several people fell. One person was hurt.

BTW removing tile is much harder than putting it down in the first place.

Tiles in a bathroom should have a rough surface. No building inspector will approve those.

1988RedT2 wrote: I'm not a tile expert, but I have done a bathroom and it came out looking great. Tiles sold for use on floors generally have a somewhat matte finish, whereas wall tiles can be super glossy. A super glossy tile would also be super slippery when wet. If you've already considered this, then please disregard, but I felt I should at least mention it.

I don't know how its done, but this is marketed as OSHA-safe for commercial use around swimming pools. I guess they've already thought of it somehow.

And I've never been on any tile that isn't snotty when wet, but I appreciate the heads-up. I guess we'll find out. I wonder if its size has something to do with it. Small tiles with frequent grout lines instead of large spans of just glossy tile? I dunno.

Yup, use sanded. Made the mistake once of using non-sanded grout on some pretty wide (and def. wider than recommended for the product) tile joints years ago because it was a quick counter in a pool window pass-through thar I figured wouldn't really matter, and I had the grout. Came out sunken, cracked, weird and rubbery-looking. 15 years later, still looks that way, but worse. Would be absolutely gross on a floor.

I've used sanded on glass tiles, and it comes clean if you work it, so don't worry about the tile finish. Just make sure you get something that will hold up in those joints, I.e. sanded.

Margie

Another vote for sanded grout, and I just laid a bunch of tile.

I know nothing about tile or grout, but I want finished pictures of the bathroom. Those tiles should look wicked.

Even if you do slip and bust your fanny.

Another vote for sanded, matte and - it's not too late! - underfloor heating.

Another vote for sanded unless you go for some of the newer epoxy grout. Epoxy is tough stuff and not so prone to shrinkage, but also takes a lot more care on clean up and naturally costs more. Left over residue is a bear to deal with.

Nice job prepping.

You want sanded grout. You asked about "the mechanics"... it has to do with the aggregate size compared to the width of the joint. The aggregates in the unsanded are too fine to have sufficient surface area to bond the joint together when it is thicker. It will crack.

Same reason you use concrete to pour a slab (mixture of portland, sand, and larger aggregate) and not mortar mix (portland and sand without the larger aggregate).

Fueled by Caffeine wrote: No building inspector will approve those.

This is not true. No building inspector would disapprove them. Building inspectors are not in the business of making design or aesthetic decisions. They are in the business of code enforcement, and there is no applicable residential code.

I don't know what "OSHA approved for use around swimming pools" means. Is it approved for a floor surface, or just walls? Does OSHA even approve tiles? Sounds like a sales pitch.

Glossy tiles WILL be much more slippery.

I'd bet it's "approved" for walls. I had 3 people come near a serious injury by putting tiles that look just like that on the steps.

I learned my lesson and checked for slip resistance on the new tiles I laid and all the different tiles I laid when I built my new house. They make slip resistant tiles and while that doesn't mean they don't get slipperier than when dry it does mean your feet won't slip out from under you when you are standing still.

That is unless your spouse uses a lot of hair strong hair conditioner and then doesn't let the water run for a while to wash it off. She's not allowed to wash her hair in my shower anymore.

That looks familiar. This was before putting in the tiles I had to cut and putting down grout (and before the bad ass vanity I built), but it looks like the same tile. I've had zero problems with it being too slippery.

SVreX wrote: Nice job prepping.

Thanks. I feel very confident about it.

You want sanded grout. You asked about "the mechanics"... it has to do with the aggregate size compared to the width of the joint. The aggregates in the unsanded are too fine to have sufficient surface area to bond the joint together when it is thicker. It will crack. Same reason you use concrete to pour a slab (mixture of portland, sand, and larger aggregate) and not mortar mix (portland and sand without the larger aggregate).

Thanks for the tech. That makes sense.

I don't know what "OSHA approved for use around swimming pools" means. Is it approved for a floor surface, or just walls? Does OSHA even approve tiles? Sounds like a sales pitch. Glossy tiles WILL be much more slippery.

OSHA approves slip resistance standards for flooring. I don't think OSHA said that this tile is OSHA approved, I think the manufacturer claims that it meets OSHA rules for slip resistance in commercial pool applications. Probably the manufacturer measured the slipperiness of it and it was below what OSHA requires so they advertised it.

For giggles this morning I laid out four square feet of tile outside the shower. When I got out of the shower it didn't seem to be very slippery at all but I know that's not a valid test.

OSHA doesn't even go that far. They set a recommendation for what they think is a minimum coefficent of traction for a wet surface should have to be considered slip resistant. They do not set swimming pool tile standards or such. So you've been a bit snookered by dishonest advertising. Anyone that says they have an OSHA approved anything is not being truthfull. Similar UL approval.

Anyhow, most regard the OSHA COF for slip resistance as inadequate. The OSHA standards does not meet the requirements for ADA and such.

I'll agree with all the others that are suggesting glazed tiles as flooring in a bathroom is not a good idea. I was one of those kids years ago, lost my front teeth to similar wet footing.

Curmudgeon wrote: Another vote for sanded grout, and I just laid a bunch of tile.

Me too.

sanded.

i have a general dislike for non sanded grout on anything but glass tile just because it seems to dry on me much faster than sanded. i do more tile than i care to think about.

I went with sanded for the 'larger aggregate' reason. Grout is basically Portland cement and without some sort of aggregate that does not have an enormous amount of strength in any direction. I have not done any real close gap or vertical tile installation, maybe it's a different story with that.

foxtrapper wrote: OSHA doesn't even go that far. They set a recommendation for what they think is a minimum coefficent of traction for a wet surface should have to be considered slip resistant. They do not set swimming pool tile standards or such. So you've been a bit snookered by dishonest advertising. Anyone that says they have an OSHA approved anything is not being truthfull. Similar UL approval.

I agree about OSHA. They do not test or approve products.

I almost agree about UL, but not quite. UL falls short of testing individual products, but they do test systems and assemblies. For example, they may test a particular type of drywall on a particular type of framing with a particular type of fasteners and a particular type, size, and quantity of penetrations, then come to the conclusion that the specific tested design is rated for a 1 hour fire rating. If your product is one of the specific components tested, then you piece of a UL tested design. Your product is then UL approved for that specific assembly. But you are right, they don't actually test individual products.

Therefore, 5/8" gypsum board (sheetrock) is NOT actually fire rated (though people call it that). It is an approved component of a rated design. Install it in a different manner, and it is technically not UL fire rated.

Ok, so I'll go sanded. Everyone keeps warning me about scratching the tile though. How do I grout without scratching things up?

SVreX wrote: Nice job prepping. You want sanded grout. You asked about "the mechanics"... it has to do with the aggregate size compared to the width of the joint. The aggregates in the unsanded are too fine to have sufficient surface area to bond the joint together when it is thicker. It will crack. Same reason you use concrete to pour a slab (mixture of portland, sand, and larger aggregate) and not mortar mix (portland and sand without the larger aggregate).

Fueled by Caffeine wrote: No building inspector will approve those.

This is not true. No building inspector would disapprove them. Building inspectors are not in the business of making design or aesthetic decisions. They are in the business of code enforcement, and there is no applicable residential code.

You are correct My experience with bathroom floor slipperiness is all related to commercial or industrial applications. Different set of rules there.

Yeah, grout does not require a lot of pressure to squeeze into the joints. Don't go bonkers with the pressure and you should be just fine. I also sorta hate to point this out, but if sanded grout will booger up the tiles so will sand on your shoes etc. such as: if there's sand on your shoe sole and you turn on the ball of your foot, well there's a nice circular scratch left behind.

and even then it shouldn't scratch.

i've yet to ever hurt any tile including glass with sanded grout.

that whole job is sanded grout, it didn't hurt the granite curb and seat either.