Porcelain sloped garage floor?

[Bouyz]

Hello Everyone. I'm new to this excellent forum and have been following along for awhile now. I want to lay 12x12 porcelain tile in my 850 sq. ft. garage. This is a three car garage with four garage doors. The rear door allows entry into my back yard. The floor is very flat but slopes approx. 2 3/4" in 17 feet toward the 3 front doors. The rear section of the garage, because of the rear door, begins to slope the other direction approx. 3/4" for the remaining 7 ft. There is a control cut along this transition area.Here is my question. Can I still tile this floor and if so, would I have to maintain a grout line along this transition area at the control cut where it begins to slope the opposite direction? Cement is 9 years old. Thanks for any input.

[HomeTeam]

My unqualified opinion: Put the grout joint over the cut; caulk it so it is flexible, but do it all over Ditra.

[cx]

Welcome, Steve.

Not at all sure why you attached this question to another fella's thread about finding someone to bullnose porcelain tiles in Boston, but maybe it's a Canadian thing, eh?

What your tiles want from that floor is that it be flat. They don't care a whit if it slopes. And the larger the tiles, the flatter they want the floor.

I suspect your floor does not consist of two flat planes that meet at that control joint at the top, but I suppose it's possible. You're the onliest one can check that for us.

Your 12x12 tiles are not gonna wanna bend over a round transition.

Given that it'll be essentially an outdoor installation, I'd wanna give thought to using an uncoupling or crack isolation membrane to help the tile installation deal with the temperature and humidity changes to which it'll be subject.

And you'll need adequate movement accommodation joints in addition to the one you'll want above that control joint. Every 8 to 12 feet in each direction is what our ANSI standards call for.

My opinion; worth price charged.

[Bouyz]

Thanks for the reply. Could not figure out how to start a new thread. eh. That transition area is about 4" to 6". There are control cuts every 8 to 9 ft. Still feeling my way around this forum.

[Houston Remodeler]

Then your new layout will need to accommodate those control joints. If you can get tiles to fit perfectly you're lucky. If not, cut to size.

[Bouyz]

So there has to be a grout line everywhere there is a control cut in the concrete?

[Houston Remodeler]

No, grout would be bad.

You need a 'soft joint' there which can be an approved caulk or a factory made expansion joint such as the ones made by Schluter.

[Houston Remodeler]

read pages 20-22 and look at the pics for examples of factory made joints.

[HomeTeam]

Paul, can't Ditra be used over the control joints without cutting the tiles to match as long as he puts in a surface joint every 8'-12' as per Schluter's Ditra installation guidelines? Now, if they are expansion joints... (cut all the way through giving complete separation of the slab, then yes, he has to have the tile joints corresponding).

[HomeTeam]

Paul: we were writing at the same time, and looking at the same pages!

[Houston Remodeler]

I'd look real hard at those control joints for cracks. Besides CX's recommendation is still valid- treat it like an outdoor installation with expansion joints every 8 feet. With that in mind why not honor the existing control joints ?

[HomeTeam]

He may not want 12, 12, 12, 12, 7, 12, 12, 12, etc.

[Bouyz]

Hi guys; My garage is just under 36 ft. wide with 2 cuts running that length and 24 ft. deep with 2 cuts also, so the cuts are 12 ft. apart one way and 8 ft. the other. I measured the depths of the cuts and got 1" to 1 1/2" There is no cracks anywhere and no signs of any shifting cement.

[Houston Remodeler]

Do you mind soft joints over the control joints?

[Bouyz]

Guess I could live with soft joints. Will have to try to plan it so that I will have as close to a full tile as possible at the joints. Would I still need Ditra?