1500 sq/ft tile - installation

[karencitas]

We just bought 1500 feet of porcelain tile (6 x 24) for the 1st floor. The tile will be in the kitchen, one bathroom (floor only) and all other living areas. We live in San Antonio (not sure if that part matters) and have a concrete slab.
There are some minor cracks in the slab (settling I think).
Do we need a membrane to prevent cracking? What do we need to do to insure that the tiles dont crack...but not go overboard with materials we do not need?

Thanks in advance for advice.

[prostuff1]

With 1500 sq.ft. of space to do I would do everything possible to make sure that the tile does not crack.

Can we get some pictures of the entire area and some close-ups of the crack that do exist in the concrete slab. Those pictures would help us know what to recommend as a crack isolation membrane.

My first thought would be to put ditra or greenskin down over the concrete and then put the tile on top of that.

[cx]

Welcome, Karen.

If you'll add that geographic location to your User Profile it'll remain permanently for reference in answering some of your questions. I can be important.

Lots and lots of tile has been installed directly to concrete slab on grade floors in your part of the country. Sometimes they survive for years without problems. Sometimes they crack.

You'll not get a guarantee against cracking regardless your setting materials or method, but you can improve your chances by using an uncoupling or crack isolation product over the concrete. Ditra is commonly recommended here, and while it does have some crack isolation properties, it is not a crack isolation product. I'd not hesitate to use it. The Green Skin that Kyle is recommending is a very new product on the market and hasn't yet much history. For serious crack isolation properties you might also wanna look at Noble Company's NobleSeal CIS. Custom's RedGard is another product used by some of our folks for the purpose.

One that I have not tried is Laticrete's 125 Sound & Crack adhesive. Setting mortar and crack isolation in one pass. Different approach.

Any of those products is gonna set you back some serious dinero, but I'd call it money well spent if it kept my tile installation intact over the long term.

But for absolutely free you can ensure that your tile is set using a good quality thinset mortar you can provide the industry recommended movement accommodation joints. That alone will go a long way toward providing a successful installation - but it won't keep your tiles from cracking if your concrete cracks.

Y'all planning to do this installation yourselves?

My opinion; worth price charged.

[karencitas]

Thank you for your advice. We are pretty sure that we will go with a product like ditra. We saved half of our cost by smart shopping online and adding two trips to Dallas in order to save money. Box store prices were twice as much and we jumped on the deal after finding a great price online. Now the investment (nearly 6000 lbs) awaits it's final home in my cluttered garage. We will not compromise on investing this much time and money (more so time than money) in order only to be disappointed sometime in the future.

To answer your question, yes, we are installing ourselves. This will be my first experience with the membrane, but I do have tile experience through remodels and previous homes. Any advice on the install of the membrane aside from getting the floor prepared? I have already scraped and removed paint and texture material as well as baseboards which I plan to replace and have done painting and drywall repairs. We are using a 6X24 in. tile and covering 1500 s.f. and hopefully will be able to go completely around the kitchen without any hiccups.

Again, I appreciate your advice. Any more would be grateful.

DC

[pgc555]

Karen,
I always chime in here and say "Don't forget to Back-Butter the tiles"
Back-buttering is the technique of using the FLAT side of the trowel to apply
a thin coat of thin set to the backs of the tiles before setting into the combed thin set. This helps to achieve as close to 100% coverage of the setting materials under your tiles. That gives you a better percentage of a successful installation for many years to come.

[CSS]

I like to use Ardex 8+9 for crack isolation. It is less expensive for material. Is a very good quality product. And for diy'ers you dont have to worry if you mixed your thinset wet enough for Ditra. Or if you get enough thinset coverage, or if you cover thinset with Ditra before it overglazes. With 8+9 just clean floor and roll out dry in 3 hrs to set tile. Or flood test in 4hrs (for real) http://www.ardex.com/productDetail.a...5&ProductID=54