tiling outdoor patio [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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08-08-2004, 12:24 PM
We're getting ready to tile our patio, and I'm hoping to get clarification on a few questions.

The patio is nearing 2 yrs old, concrete, no cracks, and drains well except for some pooling near the stairs to the house. Dimensions are 18' x 21'. We're located in Indiana, so freeze thaw is an issue. We've already selected and ordered the tile, Crossville's Weatherstone, and have designed the layout.

So my questions so far are:
1) Do we just need to apply SLC to the specific area of the patio where we have an issue with water pooling?
2) If we use a product like Ditra, do we have to honor all, none, or some of the existing control joints? We have two that are on a diagonal, and we'd really rather not have to deal with them.
3) Do we have to do anything special for the grout since it's an exterior application?


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John Bridge
08-08-2004, 05:00 PM
Hi and welcome. Please give us a first name. :)

They didn't do you any favors with those diagonal joints. And they look like expansion joints to me rather than simple control joints. I would not cross over the expansion joints even with a membrane.

I would construct a floating floor out of mortar. Make it about two inches thick, and then use the Ditra membrane over the top. This will also cure your standing water problem at the door.

Can you do it? Don't know. Can ya? ;)

08-08-2004, 08:15 PM
Hi, sorry, name is Deanna.

Are those really expansion joints? They're pretty shallow and only 3/8" wide...here's another pic that hopefully shows them better.

If these are control joints, does it change the response? We (my husband :) ) can do most anything, but I'd rather not get too complicated on this.

08-09-2004, 06:38 AM
What's that stuff in the bottom of thise joints? Looks like a sealant of some sort. That makes them expansion joints.

You treat control joints like a crack waiting to happen. An antifracture membrane and soft joints in the tile usually work.

The floating mud bed sounds like the right answer, provided you can deal with the height near the stairs.

08-09-2004, 08:38 AM
Oh, actually that's just dirt. These really are just grooves cut into the slab, with no fill material of any kind.

Well, we put our tile order on hold early this morning. We're concerned now that this isn't feasible. First off, we can't have much additional thickness on the slab because of the stairs. If we put 2" of mortar, followed by Ditra, we'll either have a very shallow bottom step, or - if we give a similar treatment to the steps - the top one (there are 2 steps) will rise over the threshold into the house. Another concern is the price of Ditra...looking to be over $2 sqft. That'll put the price of this project over $3k, and though I'd really love the texture that tile would give us, I'm thinking stain would be much more economical and at least get us some color variation.

Advice, anyone, on how to proceed??

08-09-2004, 10:38 AM
Oh, it's dirt. :D

Acid stain the concrete. Faster and you can get a stone look. Look for a professional who can work in a "grout line" pattern using masking tape. Can be very interesting. Won't fix that little puddle, though.

08-09-2004, 12:42 PM
Here's a link to hi-res photos. Click on them once to get bigger. Twice to get huge.


The tile guy called back and said Ditra was overkill. We just need a crack isolation membrane. I'd rather tile than stain. Is there something other than Ditra?

What about filling the diagonal with anchoring cement and cutting a new control joint up the middle?

Then tile the patio honoring all the control joints. No need for Ditra.

Or epoxy the thing grey with blue and white flakes. It'll match the garage!

- Doug

John Bridge
08-09-2004, 06:18 PM
Hi Doug, Welcome aboard. Whadja do, run Deanna off? ;)

If you can control the control joints, you don't absolutely need any membrane at all. I don't know that you can do that by filling them in, though. I think they will still be potential cracks. As far as I know, all waterproof tile membranes cost over a dollar a foot. If you don't like Ditra, have a look at Nobleseal. http://www.noblecompany.com

The mud job is the way to go, seriously. You could even out the two steps to make them equal. No need to raise the top one. Mud is cheap -- sand and cement. Can you do it? I think so. If you don't want to use the membrane, great. Just use a slip sheet under the new mortar bed. It has to be a minimum of about an inch and a half thick in order to provide enough mass to give it substance. :)

Rd Tile
08-09-2004, 07:00 PM
Pavers anyone? hundreds of patterns, cheaper than tile, last forever, no worries about those joints or issues with the weather.:)

08-09-2004, 08:39 PM
Yes, pavers. That's what I wanted in the first place... But we weren't married then and Deanna was building the house herself so she put in concrete with the intention of laying tile in the future. And pavers on concrete slab might be a little high off the ground. Tile looks so good. I hope we can figure out a way to get it to work.

Peggy Donahue
08-09-2004, 08:56 PM
If it can be done these are the guys that will help you figure out how. I personally put a few greys in many of these heads.

08-09-2004, 10:15 PM
Pavers anyone? hundreds of patterns, cheaper than tile, last forever, no worries about those joints or issues with the weather.:)

So how come they're not very popular in the US? I read somewhere that pavers are widely used in Europe.

Could you install pavers over existing concrete?

Rd Tile
08-10-2004, 04:40 AM
Not Popular? I'm talking about concrete pavers that come in in all shapes and sizes, just about every home in the northeast is having them installed for all flat work, walkways, pools, driveways, patios, you name it, they're everywhere, you can't beat them.:)

Yes, they can be set over concrete.:)


08-10-2004, 09:01 AM
Ditra should NOT cost $2 per square foot. tile-experts has it for as low as $1.23 sf on their website (Ditra 30 - 323sf roll for $397.50)

08-10-2004, 09:28 AM
Jackpot! Our local guy isn't the cheapest around. When he said $2.50 / sqft for Ditra I about died.

So now that we know Ditra is affordable and that the joints are control joints, what's the best way to approach it? Do I need Ditra over the entire patio, or just the joints? Do I still need to mud the thing, or was that just for when we thought they were expansion joints?

08-10-2004, 09:38 AM
So thats where those greys came from Peggy ;)

I'm with John, Slipsheet,Mudbed,Tile(using 2 soft joints for expansion control)
Ditra would be nice but not necessary with the Mudbed.

The expensive route-130 80# bags Quickcrete from HD 5-600.00 for mud
The cheap route 22 bags Portland and a couple 3 yards of washed sand.
Add your felt or 4 mil plastic and mix it in a homemade mudbox or a wheelbarrow.Or rent an Imer/combi Mudmixer :)

08-10-2004, 12:14 PM
Since the Ditra is now within the price range and wouldn't add appreciable height as a mud bed would do, maybe the Ditra is the way to go. You need the experts to detail how to treat any control/expansion joints though. I can't help you with that.

08-10-2004, 04:04 PM
I have the same situation as Deana...so I'm listening in. My cement patio is poolside and is 10-ft wide and 40-ft long. California country so I have one moderate size crack and several spider cracks. I,like Deana ,would like to cover with tile, slate or porcelin. I'm leaning towards porcelin.

Pictures may be uploaded soon by our good friend, Bob. In the meantime...I also have the problem of room not allowing a 2-inch mortor base + membrane + tile as it would then go above my entry.

I once saw on TV where they either painted or places a 1-inch (I'm guessing) layer of concrete and cut it and colored it to make it look like stone. Is that what Bob referred to as "acid stain"?

Thanks for all the good suggestions.

08-10-2004, 04:49 PM
The TCA has a spec for exterior patios like these. Substrate; sloped mud bed; Membrane; TROBA; Sloped Setting Bed; and Tile.

The idea is that you want the setting bed sloped so it sheds water and melting ice, and if any gets through the setting bed, that there is a drainage mat to promote drainage, and the moisture is then shed onto a sloped membrane and out of the installation. The freeze thaw cycle where you live can be disasterous to tile on the exterior.

08-11-2004, 07:27 AM
If I understand correctly, the membrane should not go directly over the concrete. You would always need to add a sloped mud bed?

Let's leave the joints out of it for the moment and assume I have a concrete slab that already properly slopes and is appr. 10'x10'. What would I need to do to assure a successful tile installation?

If I understand Scooter correctly, I would need not only the Ditra but the drainage mat - TROBA (also by Schluter).

John Bridge
08-11-2004, 06:33 PM

I"ve never had to install tile in your type of climate, being the Sun Belt boy I am. The main point, though, is getting the water to run off the installation quickly so that it doesn't collect underneath and expand when it becomes ice. If you can do that with just mortar and thin set, great, but from my understanding, it hasn't worked well in the norther part of the country since day one.

If it were I (and my own house), I think I would make sure the slab is sloped well or slope it with deck mud and then install Ditra over the top, making sure that no water is able to penetrate below the membrane. My thinking is that if no water is able to get in, there's no reason to provide a drainage mat. Drain what? ;)

08-11-2004, 07:35 PM
Sorry, not being familar with the format of this site I didn't realize there was a page 2 so I've been looking for my posts thinking they haven't been posted yet. Should have known you guys were to much on the ball for them not to be.

Anyway if the last few posts about tiling on an ext patio was in reply to my project, I live in sunny Southern California so we are not concerned about snow collecting or melting. I cannot slope the cement slab as its been there for the last 40 years. I had planned to run a drain the length of the patio on the poolside of the pool fence (pictures of what we are talking about should be posted soon). So again I'm not really that concerned about drainage as I plan to just hose the patio off toward the drain.

Simply what I nee to know is
1. Must the paint on the cement be removed first?
2. Must we use a membrane and exactly what is a membrane?
3. Is porcelin a good choice?
4. When completed what the least height increase I could get a way with? Again concerned about the patio tile going above back entry slider door.

Now that I know where to find you I'll be staying up to date with the posting

Thanks guys

Roger :yipee:

08-11-2004, 07:47 PM
I agree proper slope is essential. If that has been achieved via the concrete then a mud bed would not be required? Granted, in Deana's case there is a portion of the slab near the stairs that is pooling water so that needs to be addressed. It just sounded like the answers all involved raising the height by 2" or so to make it acceptable for tile.

My example was purely hypothetical and was an attempt to clarify whether a full mud bed over an existing, properly sloped concrete slab was necessary or if a membrane, Ditra, could be applied directly to the concrete slab.

I wish I was in the Sun Belt, New England weather, especially in the Winter months, is not my cup of tea. Lived in Guam for 4 years when I was younger and would love to retire in a similar climate some day!