Hi Guys,

I'm going to install quarry 6X6 tiles I believe 1/2" thick in restaurant behind bar and in the kitchen.I have just 4 days to do this job so I do have time issue.
The house is old(over 100 old) and there is little bit issue with subfloor.It's partialy wet since they are using kitchen.Now there are vinyl tiles .I will remove them.There is a 3/4"plywood on top of old joist.I plan to leave subfloor plywood there.
Questions:

1. what type of underlayment should I use between plywood and quarry tiles--1/4" or 1/2"backerboard vs.Kerdy, or some other product.Or I can just lay them straight to subfloor with thick mortar bed which I think may crack ? I just want to prevent future cracks.
2. Type of mortar or cementiuos bed and trowel size? If cementiniuos bed what is the proper mixture of sand,cement... How thick mortar bed needs to be?
3. grout type and size?
4. How can I cut quarry tile? May I use wet saw,grinder or other tool? I heard quarry tiles are really hard.

Thanks for this great forum.Any input,suggestion would be really appreciated!

Mike

Hi Mike,

Thanks for the call and for coming here to ask your question.

You are asking about two very different methods. One is 1/4" concrete backer board over plywood, the other a "mud" job consisting of 1 1/4" thick mixture of sand/cement. If you feel comfortable doing a mud job and can raise the floor the extra thickness, go ahead. Otherwise go with concrete backer or a membrane such as Ditra.

Chances are the vinyl tiles were installed on 1/4" plywood, if so, remove the plywood and tiles together. I would also suspect some water damage in a floor like that. Once you feel the subfloor is OK, you should consider adding a sheet of 1/2" underlayment grade plywood, then either 1/4" concrete board or Ditra. Or, go with the mud job. Although much thicker, the mud method would allow you to make the floor flat if that's one of the issues you were eluding to above.

1. If you add ply get 1/2" or thicker C/C or B/C, then 1/4" concrete board or Ditra. If you do a mud job it's tarpaper, metal lath, 1 1/4" mortar which is 1:5 cement/sand mixed dry. Either of these require more info so don't just go do it cuz there's more details for you to know.

2. See #1

3. Sanded or epoxy if you need the best and $$$ is not an issue. 1/4" gap roughly.

4. Straight cuts can be made with good tile cutter, but saw is required too.

Mike, a few of your questions tells me you should not be charging people to do this work cuz you're learning on their dime. It's obvious you're not qualified. Can you sub out this portion of the work? No offense. I remember talking you through a handicap shower last year, this is not how a contractor should operate. We will help you if you insist, but your client deserves for the work to be done right. It's very difficult to do repairs in a restaurant since they don't wanna close.

Jaz

Mike,

My suggestion to you is to stay away from the sand/cement/wire lath method. Not a lot of guys do it any more because it's time consuming, it's hard work, and there aren't a lot of guys around that are really good at it. At one time, it was simply how it was done, but with newer materials availible most people have gotten away from it and it has become a bit of a lost art. (Not to mention that skilled labour is expensive and, in today's market, the additional work makes it too expensive unless it is absolutely necessary.)

It is true that it will allow you to make your floor dead flat, but you are levelling it yourself by hand, so if you don't know what you are doing, you can make the level really bad really fast.

Keep in mind that your 6"x6" tiles will be more dificult to keep flat and level than a larger tile. They will want to take the shape of the floor underneath (simiar to mosaics) so you want to start with the best surface possible. I'd go with Jaz's suggestion of building the floor up with plywood and/or concrete board.

Also, in case you're curious, the recommended joint size (by the book) is the thickness of the tile. This is why you often see rather large joint lines in commercial kitchens where they have used quarry tile. However, you can go a little smaller for appearance sake. I wouldn't go smaller than 1/4 inch.

For notch size, I'd probably go with a 1/2"x1/2". If your floor is dead flat, you may be able to get away with a 3/8", but if you have and rolls or humps to contend with, the 3/8" may not be enough.

Hey guys,

Thank you very much for your great input on this topic.
Jaz, I would never put my customers money in jeopardy.I would never take job if I'm not sure I can handle it.I lay regular tiles, but I have never done quarry tiles.That doesn't mean I cannot do it right.It's just another challenge for me and I'm sure I can handle it!
Jaz don't worry there is gonna be more qualified tilers on job site besides me.I just wanted to know few upfront information just for my self, which I'm sure tile guys which will operate on job site already know.
Btw that job on handicap shower turn out really nice, customers are happy.

Thanks again guys, you were great source of information!

Michal

thanks for your great input, I really appreciate!
Michal

I agree with the above, stay away from the floating, sounds like to me gluing and screwing a 1/2" hardie board or equal to the old subfloor is the way to go. Leveling in a commercial kitchen would not be the issue plus no one in the kichen area cares if the tiled floor is flat. As far s the cuts are concerned, quarry tile is not as hard as granite, but close, you will need the proper saw blade, we have had good luck using a felker tm-6 or the tm-7. One last note you will need to use an epoxy grout, " spectra lock " is the easiest to use and is available in all the colors. One more note, I don't like the 1/4" backerboard at all unless you thinset down each section and than screw.I have never had proper results with this.

Hewittile,
I will definately use 1/2" Durack and probably use that spectra grout, it sounds like good idea.
Thanks for great tips!

What's the alternative? That is the way all backerboards are to be installed to floors. I've used 1/2", 5/16" & 1/4", for floors although the 1/2" is made for walls unless you want/need the xtra height.

Jaz

In a commercial kitchen and bar area, epoxy may be a good idea, but there are a couple of things to keep in mind.

First off, if you choose to go with the Specrta Lock, make sure you get the right one. I have found that distruibutors often try to push the Spectra Lock Pro. The Spectra Lock Pro is a nice grout to work with, but it is not a commercial grade epoxy. It is an epoxy, with all of the components, but falls a little closer to the "stain resistant grout" category geared more towards residential applications. It is not rated for commercial kitchens. For a commercial application, steer more towards the Specra Lock 2000.

http://www.laticrete.com/Portals/0/datasheets/LDS681.0.pdf

The other thing to keep in mind is the cost. Your epoxy grout will cost you at least 5 times as much as a good sanded grout. This is the main reason that we tend not to use epoxy unless it is specifically called for. Unless it is for a specific application (mostly commercial) people simply don't want to pay for it. If cost is an issue, you may be better to lean towards a good sanded grout with an additive or a sealer to be applied after the grout is cured.

In your commercial application, the epoxy would definately perform better. No cement based grout will last as long or be as durable. It just may be a hard sell because of the price.

Jaz

Height is point where we are concerned, but if I choose 1/4" Durack we would have to probably put mortar underneath.Than height compare to 1/2" Durack would be the same.And work will take more time.I'm always mentioning Durack which I think is more sturdier than other backerboards.Just my thoughts.

thanks