# Tiling an outdoor deck



## Rick Molner (Apr 5, 2014)

I've built a number of decks in my time and done a fair amount of tile work indoors, but I now have a customer who is wanting to construct a large tiled deck, and this will be my first such project.

Some things are pretty straightforward, such as needing a good waterproofing membrane that will also isolate the tile from what's under it, using unglazed porcelain tile for the surface, getting 100% coverage with modified thin set (for freeze/thaw cycles), keeping small grout lines (to minimize any moisture intrusion) and planning expansion breaks every 10' or so (this is an almost 1,000 sq ft deck). For structure, I plan to construct the deck using I-joists, microlams, and solid decking supported by steel columns; and designing to deflection numbers in the 600+ range for a nice, solid surface so I can use the mix of 12x12 and 18x18 tiles the customer wants.

For waterproofing, I'm leaning toward Noble's Noble Deck, installed over 1/4" or maybe 1/2" Durock to provide additional isolation from the wood decking.

So here is where I'd really like some thoughts from folks with experience doing this kinda work! Has anyone used Noble Deck, and if so ever had any issues? Assuming it works well (and it's both a waterproofing and heavy duty crack isolation membrane, so hopefully it should), does it matter how thick the Durock layer is under it? Under that, should I be thinking exterior plywood for the decking or maybe Advantech? Is it worth maybr going to two decking layers offset for additional isolation since I'm using Durock, or is that overkill?

I know everyone has their favorite way of doing things, and there's often more than one way to do a good job. I want this deck to be a long-lasting product for the customer, and maybe launch me off into doing additional waterproof deck projects. :clap:


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## CarpenterSFO (Dec 12, 2012)

Why solid wood decking? Why not ply? Stronger, less movement, less expensive, easier to install.

Edit: Maybe by "solid" you don't exclude plywood. Ply should be fine; others who have used Advantech floor can comment on that.


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## CarpenterSFO (Dec 12, 2012)

Semi on-topic - Exterior tiled decks usually fail around the edges. Just about any membrane will do the job in the field just fine. Around the edges you have to be fanatical about flashing, transitions, and other details.


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## MIKE ANTONETTI (Jul 17, 2012)

I'd look into Schluter instead, I've gone to their class and yes many tiled decks fail, I personally haven't done any but the concept of Schluters system of drainage along edge as Carp. SFO stated seams to be engineered accountable to weathers extremes.


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## rotarex (Mar 31, 2008)

I have seen it done before, but what happen after the fact i don't know.

but if i was doing tile on the deck i would make sure my live-load is minimum 100 psf. as each deflect would cause the grout to crack and moister build up etc etc. 

we use ardex exterior cement when tiling front entrance, but thats on cement not wood.

hmmm..... may i suggest after the deck is built with 100 psf liveload that you find someone or if you can, to screed (dry pack a good 2 inches ) and tile on that


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## Rick Molner (Apr 5, 2014)

Carp -- Thanks! Did not mean to imply solid "board" decking and I was in fact talking about using plywood or something else in a sheet like one of the improved OSBs... by "solid" I was just trying to differentiate from individual 2x6 boards on a typical deck. 

I already know that one of the real issues with outdoor tile installations is the wide variations in humidity over unconditioned space, and to a lesser degree wide swings in temperature. The result is differential movement between the substrate and the tile, and I just don't know whether plywood or one of the improved OSBs like Advantech would be a better choice to reduce this movement through seasonal changes. 

ProtectoWrap says their AFM-WM product can be installed directly over plywood (they recommend two offset layers), but having porcelain tile that moves very little on top of plywood that moves a lot more, even with the membrane in between them, scares me a little.

Roger on your comments about flashing and details. I do plan to strip 5" of stucco on the wall over the ledger location, install a metal flashing first and then run the membrane up the wall under the existing tar paper. With the acrylic top coat on the replaced stucco being very weather resistant, I think those steps should cover the wall side of the deck. Then I plan to wrap edge flashing on the other sides and run the membrane over metal drip edging, plus a gutter system on the downhill side. Any other ideas would be much appreciated!

Mike -- Thanks! I looked briefly at the Schluter system, but I have heard of some problems. Maybe that's only because there is more written about it compared to the Noble system. I'll take a more in-depth look at it. Sure hope someone weighs in who has real-world experience with the NobleDeck system before I rule it out.


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## CarpenterSFO (Dec 12, 2012)

I like the Schluter products - Kerdi, Ditra, all the edges and transitions - and have used them inside and out. I've never had any problems with them.

I've never used Noble, so I can't offer any useful advice about that.


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## Rick Molner (Apr 5, 2014)

Rotarex -- Thanks! I am designing the deck for 3-4 times the normal recommended 40 psf which gets me over 100. I-joists will be on 12 inch centers providing lots of strength and minimum deflection. I'd also planned on 1-1/8" decking, but may decide do two offset 3/4" layers is a better approach, but either one makes for a really solid surface. I'm using the Forte software package to check out I-joist and microlam sizing and hanger requirements, and have lots of margin.

I thought about lightweight concrete/cement, but I have to believe there's a way to do this with CBU rated for outdoor use like Durock. Putting modified thin set between the plywood (or Advantech) and the CBU and again under the tile seems like I'd have several flexible layers to handle any movement. Add a soft joint every 10 feet in both directions and I feel pretty good about it. On the other hand, if no one has ever gone this route, maybe there's a reason...?


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## angus242 (Oct 20, 2007)

NobleDeck, without a doubt, better than the Schluter solution. Of course, whatever you're used to is the "best". Knowing the product and how to properly install is half the battle. 

This is what I feel is the best way to do a deck:


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## GO Remodeling (Apr 5, 2005)

This deck is Dricore panels over a living space. A thick roofing membrane was placed as primary waterproofing. Then 3-4" of concrete placed to pitch to edge. I covered the concrete with Noble Deck set with Laticrete Platinum thinset. I recommend an air powered caulk gun for the sealant ( about 700 lf). Everything flashed, Noble corners and drip edge installed.


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## GO Remodeling (Apr 5, 2005)

Another deck was installed over 2-3" mud bed pitched to drain under a covered porch. Flashing and sealant are a must.


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## Tech Dawg (Dec 13, 2010)

I recently saw a product from FinPan that was pretty interesting for decks. "TI Proboard"

Just set the board on the joists, fill the grooves with fat mud and then carry on with a tile installation with membrane. Theres some videos on finpan's site.


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## Dan_Watson (Mar 1, 2008)

Paverdeck framing and then kirdi/weidi board?


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## GO Remodeling (Apr 5, 2005)

The TI board looks intetesting. I like a mud bed vs. cbd and plywood. I would seal the screwheads and seams with WEDI glue. And make a flashing for the house attachment and drip edge.


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## Rick Molner (Apr 5, 2014)

Been out of the state for a few weeks on a long vacation waiting for warmer weather. Thanks for the inputs; plans are now in review by a structural engineer so I can get a stamp, a permit, and get started. I've decided to go with 1) a 3/16 per foot slope away from the house; 2) two offset layers of 3/4" untreated exterior glue T&G plywood (Sturd-I-Floor); 3) a layer of 1/2" Durock; 4) Noble Deck CPE membrane for isolation & waterproofing, attached to the Durock with Noble EXT; and 5) porcelain tile attached with modified thin set, 100% coverage, incorporating backer rod/silicon caulk expansion joints between perimeter tile and the field and then every 8-10 feet in both directions in the field. There will of course be flashing and drip edging routing water into a gutter system.

The deck surface deflection will exceed 720/360 and with enough care putting the tile in place to minimize water from getting under them I'm convinced this system will work well. Analysis says it'll handle many cycles of large swings in humidity and temperature; we'll see how it works in practice and I'll post results.


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## GO Remodeling (Apr 5, 2005)

Two things: 
I used Laticrete Platinum for setting membrane and tile. It's highly modified and mixes with water. It seems to go further than the Ext.

What type of grout do you use? I've used Htc Mapei cementous grout and Fusion Pro for exterior work.


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## Rick Molner (Apr 5, 2014)

Laticrete is definitely a great product, and I really like it for setting tile. My inclination toward EXT to stick down the membrane is because I've never used Noble Deck before and I'm trusting that Noble has optimized it for their product. Plus I don't have to mix it and I've found it at a pretty good price point. Sounds like you've used EXT and therefore have some experience with Noble Deck? Any lessons learned?

I'm still pondering the best grout to use. Originally I was thinking epoxy, like Spectralok or Mapei Opticolor, but I'm not sure it's worth the cost or hassle. I've never used Fusion but heard it is really good, but also difficult to work with. Since I'm putting in colored silicon expansion joints, I'm debating whether using it for the entire job rather than grout would help to ensure no water intrusion? Getting even a trace of water down between the tile is my biggest concern, given the number of freeze/thaw cycles we see here in Colorado.


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## cleveman (Dec 28, 2007)

I think the OP mentioned from the beginning that he had to use unglazed porcelain.

Why is this? I think you can use glazed.

You will get water under the tile. I believe this is the reason why the deck is sloped and one of the reasons for the membrane.

I replaced some tile on a stoop and the project manager went with a glazed porcelain and portland based grout.

The tile being replaced and the grout were in fine shape, they just wanted to update.


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## Rick Molner (Apr 5, 2014)

The unglazed porcelain provides for a less slippery surface when wet, especially when it's textured. I also like the "color thru" aspect. I don't plan on chipping it, but it's nice having the body color be very similar to the surface.

I'm not concerned about water getting to the deck structure, since the membrane and good flashing details should prevent that, barring some failure. And of course the porcelain will prevent all but microscopic moisture levels from getting thru the tile. But I am concerned about getting enough moisture thru the grout that subsequent freezing would build up enough pressure to overcome the elasticity of the modified thin set and pop a tile. We get enough sun and nighttime freezing that the installation will see dozens (probably many dozens) of freeze/thaw cycles in the winter.

It just struck me when pondering grout that if 100% silicon works to allow for tile movement and it seems to adhere well, why not make every grout line an expansion joint. Seems like an odd approach, but I wonder what would be the down side.


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## Rick Molner (Apr 5, 2014)

By the way, one such silicon product that comes in a range of colors is Mapei's Mapesil AC, which is made for use in damp areas, even under water. I've never used it, but it seems like it would be pretty effective for keeping water out unless it degrades significantly over time. Maybe someone perusing this thread has some experience with it...


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## GO Remodeling (Apr 5, 2005)

You've got to be a homeowner. No mechanic would want to silicone the amount of grout joint you're thinking about.

A few thoughts on silicone: is it uv stable? It gets dirty and moldy in showers and you want to use it outside in all that grime?

No need to go rogue. There are proven materials to use.


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## Inner10 (Mar 12, 2009)

olzo55 said:


> You've got to be a homeowner. No mechanic would want to silicone the amount of grout joint you're thinking about.
> 
> A few thoughts on silicone: is it uv stable? It gets dirty and moldy in showers and you want to use it outside in all that grime?
> 
> No need to go rogue. There are proven materials to use.


Iirc floormaster siliconed every joint on his wood and porcelain floor...madness.


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## Rick Molner (Apr 5, 2014)

Fair enough. As a deck and basement guy, I've drawn pretty much within the lines until now. This'll be my first waterproof deck and the goal is a nice finished product, minimal maintenance and happy homeowners, even if it means a little more effort for me. I understand TJIs, 2-bys, loads and deflection... but tiling is not my expertise nor my favorite thing to do. Which is why I'm looking for input from those here who specialize in tile work...


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## GO Remodeling (Apr 5, 2005)

Inner10 said:


> Iirc floormaster siliconed every joint on his wood and porcelain floor...madness.


I can see the reasoning for a wood to tile joint being siliconed vs. grout.
But it was a single tile surrounded by wood, if I remember correctly.


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## Inner10 (Mar 12, 2009)

olzo55 said:


> I can see the reasoning for a wood to tile joint being siliconed vs. grout.
> But it was a single tile surrounded by wood, if I remember correctly.


Many single tiles.

I'd pay to see a guy sponge off a floor caulked with silicone for grout. :laughing:


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## GO Remodeling (Apr 5, 2005)

Inner10 said:


> Many single tiles.
> 
> I'd pay to see a guy sponge off a floor caulked with silicone for grout. :laughing:


I'll bring the beer, you get the chairs.


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