Help with substrate ID

Hello all -- I am an apartment dweller looking for some expert advice. A week after the soap dish in our shower stall was "repaired," it fell off the wall and shattered. Based on what I'm reading here, it appears as if mastic was used as the adhesive, with silicone caulk on the edges. This was all done in one step. The adhesive was wet and peeled off like putty. It sounds as if the installer should have used thinset as the adhesive and grout around the edges a day later. Is this correct? Secondly, what am I to make of the packed dirt (or what looks like dirt) substrate? Is that what it looks like, and if so, what prep should be done in advance of applying the thinset. Thanks for all of your help.

Here is the site, awaiting reinstallation:
http://www.floorstransformed.com/ceramic-tile-forum/photos/2491.jpg

Well let's get some other opinions but that substrate looks like oriented strand board to me. If this is the case, you can forget having a soap dish there again. In fact, you should be wearing steel toed boots to take a shower from here on in.

OK, one vote for oriented strand board. I should also add: this is in a brownstone dating back 130 years (although presumably the shower innards aren't of the same vintage). It simply looks clumpy, like packed dirt.

What happens to it if you tickle it with a sharp object? Does it crumble? Does it splinter? Can you pick off those little bumps?

Scratch it with a sharp (something) and take another picrture.

Definately need another pic like Bud said. I don't know why, but I'm kind of leaning towards it being just plain sheetrock.

Here's a closer look:

http://www.floorstransformed.com/ceramic-tile-forum/photos/2492.jpg

It feels as you'd expect very firm dirt (like hardpan that's been baked by the sun) to feel, and you can see fine hairlike fibers in the picture.

Old, old, plaster browncoat maybe. Probably Portland cement, local clay soil and horse hair.

Sounds prehistoric. What adhesives or procedures would you use to ensure that the dish bonds strongly to this stuff?

"ensure"

Have no idea! Try a modified thinset. Maybe even 100% silicone.

I agree, use thin set mortar, either modified or unmodified, but first drill several holes in the wall so the thin set will anchor its self better.

Jaz

Thanks for the expert advice -- I realize this was a pretty obscure one to throw at the forum.

I would like to suggest using an epoxy adhesive. Try the Laticrete 310. It is a two part, easy to mix, and will hold.

The work was done today -- he actually inserted zinc screws through the new dish into lead anchors in the substrate. Probably not ideal from a cosmetic perspective, but he felt like this would suffice (and only require one visit). No adhesive at all was used, as far as I could tell. The dish was finished with silicone caulk, not grout, but since the screws will support all of the weight by themselves, I assume this is alright. He appreciate your insights into the nature of the substrate -- despite working on many brownstones, he said it had been a long time since he had seen anything quite like this (most showers having been gutted and refinished post-horsehair era).

HE DID WHAT?

HOLY CRAP!

And that's OK with you?

Probably not ideal from a cosmetic perspective,

YA THINK!?

I'm a tenant, not the (absentee) owner, what can I say. I had little control over what the handyman ultimately decided to do, but hoped to understand more about it in hopes of influencing the process somehow. What problems should I foresee with this unorthodox fix?

I'm a tenant, not the (absentee) owner, what can I say.

OK, in that case, I love it, think it's a grand idea, and know you will enjoy it from now on. Be sure to smear a few gobs of silicone around the head of the bolts and the washers (there are washers aren't there?) to insure against water migration travelling the path of the bolts into the substrate (and beyond).

I had little control over what the handyman ultimately decided to do,

Calling this mental dwarf a "handyman" is being much too kind to him.

What problems should I foresee with this unorthodox fix?

I would be installing security chains and interior slide bolts on all my doors and windows. You should also own a gun if you don't already.

Hah, well, it took him an hour just to drill the holes in the ceramic dish, so it's pretty obvious this isn't the recommended installation method. I was in favor of following Jazman's lead and drilling shallow holes in the substrate only, then using thinset behind, waiting for it to cure, followed by grout (either epoxy or ordinary) along the seams, but I wasn't calling the shots. I think there is silicone smeared around the head of the screws -- there are no washers, however. Live and learn.

Oh well, who needs washers anyway?

Jangel had a good idea with the epoxy thinset. A little expensive but one helluva bond for sure. A little off topic but does anyong know if you can purchase little buckets of two part epoxy?

Not sure what your trying to do, but have you tried JB Weld?

Buying even the minimum quantity of epoxy offered would be super expensive just to install a soap dish.

You can see by the way the soap dish finally got installed that there is no way the property owner would go the expense of epoxy thinset. The owner as well as the so-called "handyman" are both low budget jack legs.

End of thread.