Exterior Balcony in PA

[Hafer]

I'd like if all the experienced folks would weigh in on this plan:
I'm replacing a 180 sq. ft. flat roof that covers an arched masonry porch, the kind of deal you can walk out onto from a 2nd story bedroom. Circa 1926, but very solid. I ripped off all the old leaking roof, sistered new 8'6" 2X8s onto the existing 2X8s, (yes, there is adequate built-in slope) they all rest on the masonry AND tie into a double 2X8 plate that forms the long side of the 20.5 X 8.5 deck. 3/4" Advantech T&G OSB (a good product) screwed down to that, Redguarded. Feels solid as rock. Passes the Deflectolator with flying colors. Two tile guys stomped around on it and said I'm good to go with only 1/4" PermaBase cement board, Redguard, Versabond thinset and my tile. My questions:
1. Do I need a Ditra or NobleDeck-type product, or am I good without it?
2. Tile guys say ONLY through-body porcelain, but there's a Daltile quarry tile that would look perfect with the vintage of this place. Tile guy 1 says I don't want the maintenance of quarry, Daltile guy says I have to seal anything I use, quarry or not. The daltile quarry is "rated for commercial and residential exterior freezing-thawing conditions when installed properly."
3. After the tile goes down, there will be a wrought iron railing that will need to get re-installed, meaning I'll be drilling into those tiles and the subfloor. Can you help me avoid trouble?

[sandbagger]

1. we like Ditra here.

2. you don't seal porcelain. the biggest advantage to "through body" is that chips aren't as visible. he prolly figures that's a consideration with an exterior install. whatever you use, "when installed properly" is the key.

3. I take it you are drilling in the horizontal surface? we don't do that in showers for the simple reason that water always wins. fill the holes with sillycone, but water is going to get in there eventually. maybe someone will have another suggestion.

[Hafer]

Thanks, Art. Regarding #3, Yes, I am now thinking I'll need to find another way to anchor those wrought iron rail posts besides drilling into the tile floor. I wonder if I can somehow install/adhere the metal mounts that hold the rails to the subfloor, protect the subfloor with more Redguard or some kind of waterproofing treatment, then tile around it?

[sandbagger]

Greg - that sounds a little extreme. Ideally you would mount to a vertical surface, but you are pretty much stuck since it's a reuse of the old rail. I'm thinking the best you can probably do is lots of silicone in the screw holes and under the mounting bases. Even better is Kerdi-fix. Make sure the mounts aren't in a low spot than can collect water.

[Duradekspert]

If your looking for an approved waterproofing membrane then Tiledek from Duradek is a great choice. It comes with a 10 year waterproofing warranty and is able to have tile installed directly on top! if you want more info you can check out the Duradek website.
Take care and

[sandbagger]

unfortunately, Katie, the issue is still that Greg will have to penetrate the membrane to mount his railing.

[Duradekspert]

ah, yes... I've attempted to attach a picture... this is how we reccomend attatching posts if they must be surface mounted...

another option is to use a fascia mount system...
I hope this helps...
Thanks

[johntrent]

Greg - welcome to the forum. I don't think Redguard is approved to be used as an exterior waterproofing - I maybe wrong & I am sure someone will correct me if so -

That being said - is this over an occupied space? Is there a finished ceiling below? If so you need a different approach anyway.

We usually attach the railing supports first then ditra around them, cut a kerdi patch & kerdi fix under it & above it - I'll try to find a pic.

[Hafer]

All: Excellent advice, looks like I have to come up with a good design to lock in the 7 small, cup-like holders that accept my metal railing posts. John, this balcony sits over an exterior open-arched porch. There is an old metal lathe and plaster ceiling underneath, the arches provide good protection from rain, but it's an open area, not closed in at all. I will need to do some repair to the ceiling after I get the top deck tiled, some fell, alerting me to the roof leak in the first place. FYI, the Redguard container does say it's good for exterior decks. I have beeen VERY impressed with this product. I don't intend to do this, but I firmly believe I could slap on another coat and make it through the winter without harming the Advantech OSB one bit. It's like I have a tough plastic coating on this roof deck.

One new wrinkle for you pros: I want to use bullnose at the deck edges, AND run a two-inch strip of tile vertically beneath the bullnose edge, above the fascia. So, the way in which water drains from under the tile and finds the drip edge seems important. This will allow you to see the tile from the street, and will tie in nicely to this 1926 Hollywood-style stucco. Balcony is on the left in the photo...

[ceramictec]

Greg,

I don't think RedGard or other liquid membranes sgould be open and exposed to the elements without being covered. the UV rays I think break it down. you might look into that.

my only 2 ways I would do on an exterior deck is Ditra w/kerdi band or Noble Deck.

[Mountain Tile]

Nice pics John. I like the method John is showing you greg. I would never use redgaurd on an exterior application, I don't care what the can says.

[CSS]

I agree Redgaurd not the best. Ardex 8+9 is roll on wp for interior or exterior and is approved for wp over living area some are not.

The issue I have is your substrate temp needs to be at least this means a minimum of 50 degrees during curing process. I have not yet found one thinset that says otherwise. Not sure but im guessing its pretty cold over there right now. For the best quality install you should wait for temps to rise. Both Quarry and porcelain are good materials either would work great.

[Hafer]

Robo: Ardex 8+9 it is, thanks for telling me about the product. Talked with the Ardex rep, he sold me on it, I picked up enough to do the job. Weather is still warm enough around here, as long as I choose my days carefully. I intend to get the deck sealed up and tiled before it's too late this year.

[johntrent]

Thanks Chuck - I am a believer in that system - I had to cut into a deck we had done like that for another situation - wish I had taken a picture but didn't - anyway it was a perfect crosscut section. There was definitely no moisture within the assembly - good stuff