Corian over kerdi

[Rendog]

I'm building a custom shower with corner seat. The shower is framed kd 2x4's with 1/2" hardyboard. The seat has exterior plywood under the hardyboard. The entire shower, floor to ceiling is covered with kerdi including a custom mud base and kerdi drain. The seat top, nitch bottom and entire door jam will be corian. The corian around the door jam will be proud of the wall tile by 1/4" and the tile will butt up to it. The corian fabricator suggests adhering the corian wilth 100% silicone. Does this sound right to you John Bridge or anyone else with experiance here???

Renny

[John Bridge]

Hi Renny,

I think you're saying the seat top is also covered with Kerdi? I would let the Corian guy install the way he wants. He's the man.

[Rendog]

Well actually I'm installing the corian so I guess I'm the man and since you're the kerdi man I thought I'd ask you! I don't see any problem with the silicone but was unsure how it would react with the kerdi. I guess I'll let you know.
Renny

[earlyretirement]

A good quality 100%silicone will have excellent adhesion characteristics. It may take a while to cure being sanwiched between kerdi and corian, but should do the trick fine. Kitchen and bath type 100%silicone often contains mold/mildew inhibitors, which is a minor plus.

[Mountain Tile]

I would use Ditra set or versabond thinset to set the seat.

[kerdibird]

Yeah Trevor, how do you plan to slope the seat with silicone?

[kerdibird]

Oh I got it, 3 tubes at the back 2 at the front right?
But then you might as well have a trowel.

[earlyretirement]

If the bench structure is Kerdi'd, and properly pitched - the Corian will also be properly pitched. Art, you have a serious wild hair, you know where!

Good luck with you bench Rendog.

[gueuzeman]

I'm with trevor, the seat should have had pitch built into it in the framing. Thinset and corian sound like a bad mix to me, even your hallowed ditra-set.

I think art's just being facetious. On the jambs, I'll bet the toughest thing is to get the pieces wedged in tight and holding them straight while they cure. Anyone think that a few spots of 5 min epoxy would be a good thing?

gueuze

[kerdibird]

You should take that early retirement package.
I'm losing hair, but getting more head.
BTW what reasoning is behind this decision to not install corian with thinset?
Is full coverage not important?
How would corian differ from a piece of marble or granite other then them being made by nature vs man?
I can't see any advantage to using silicone, for which reason I stick to my opinion.

[gueuzeman]

KB- corian- zero absorption, 100% plastic. Marble/granite, some porosity, especially on unpolished backside. I',m just saying, but you may be right.

I do think that part of it is that corian and stone installers are not trowel guys, they're caulk guys.

gueuze

[Davy]

I would hope the seat already has a pitch built into it. I would probably use a white modified thinset to get full coverage. It'll stick to glass, it should stick to plastic.

[John Bridge]

Well, it looks like we have a confused mess here. This has never happened before on the John Bridge Forums.

I'm going by experience, the experience of watching Corian pros build showers through the years. In every single case I saw them using silicone for the entire project, never thin set.

I also know that silicone bonds well to Kerdi. While it's true it will take some time for it to cure, I still think that's the way to go. I wouldn't try to do any buildup at all, though. That won't work even if it cures. You might put spots of silicone at about six inch intervals in all directions and squish the seat top into them. Refrain from caulking the edges/seams for several days. That will allow air under the top.

Unlike tile and stone, Corian does not need to be fully supported. It has a bit of flex to it.

[Rendog]

Well I've done enough benches to know that it's always best to build the slope into the framing which is what I did here. Same with the nitch bottom which is more than 6" deep. As for the jams, sometimes I use a little hot glue stick to hold things in place until the caulk dries. However this time I can wedge 2 x 4's first top to bottom. let dry. than set the sides the same way. By the way, my wife is a kitchen/bath designer and she had the corian idea to match the vanity top. I think it will look good. The corian is being delivered friday and than I'll start the tile. I'll send photos when completed. Thanks for the lively discussion.
Renny

[earlyretirement]

Hey Art, I bow to your vastly superior tiling know-how, let's call a truce and please do sanction my giving advice if I feel it will cause no harm.

If you really feel strongly I shouldn't offer advice I will stop doing so.

BTW, I'm a scientist that enjoys practicing all trades, not just a sheetrocker (a few hundred *too many* sheets hung!)