Perhaps put a new surface over the cracked surface. We just did a shower where the tiles were not square with the wall so we are putting a new tile over the existing one.

Have no suggestions, hopefully your fabricator will be able to come up with something, and I would assume that he would have to be liable for the cost of ripping apart your shower...ugh.

I totally can see how this could have happened. We ordered a custom cultured marble shower base, and like yours it has to be installed before the tiling...we haven't taken off the protective cardboard covering (no plans to do so until tiling is done), but I have wondered if maybe we shouldn't just to peek underneath, and make sure it's all OK before we start the walls...

I hope it gets resolved satisfactorily, can't imagine how it could be 'repaired' though... What kind of waterproofing is under your shower pan?

raehelen. Don't make the same mistake. Take a peak now before it is too late. At least if there is a problem down the line, you will know when it happened and who to blame.

The shower pan is hot mopped underneath the soapstone and mortar or thinset they used.

I am not an expert.

There is no chance that the base came in two pieces is there? If it did, and was installed then it should have been epoxied together, in my opinion. And the surface smoothed again at the seam to match.

Great question Raehelen. Additionally, is the underneath area sloped? If it has the proper slope then I would imagine water would drain to the outlet drain if the underneath area is connected to the drain. Then the soapstone pan functions as two huge tiles. But my thought is that the bottom of the soapstone is flat, as it would be difficult to sculpt both sides of the pan to shed water, make stable, and install. It would be like trying to install a toy top, always moving around. My guess is that the floor may have had a high spot and the stone "popped" on top of this area when pressure of standing in the pan occurred, causing the crack. I wonder if it should have been set in a thick bed of mortar, or dry mix, to allow some better covering of the floor irregularities, assuming that is the problem.

PLEASE keep us posted on this whole affair. It will be very helpful for GW'ers in the future.

Two issues would concern me about your description of the install. First, is it a solid flat slab with no slope to the drain? Typically when slab is used for a shower floor, it is done in four pie shaped pieces to allow drainage slope to the center, and unless your slab was sculpted down to provide slope, how is the water directed to the drain?

Second, maybe it's a regional thing, but here any shower floor slab or tile for that matter is always laid on a bed of dry pack mortar (sloped to the drain) on top of the hot mop pan, which provides a solid void free base for the material and also allows for any water seepage to the drain's weep holes.

If your (flat) slab was placed directly on the hot mop with thin set, there is the potential for cracking when weight is applied over any area with an irregularity, (high or low spot).

It is a solid slab, but because soapstone is soft, they hone the stone down toward the drain from all sides.

I am not clear on whether they used dry pack mortar underneath, but I certainly hope they did in order to create a flat surface for the stone. However, I do recall that my contractor got angry that they dinged the hot mop a little when they were installing. He did a soak test afterwards to make sure there were no leaks, but this makes me wonder where exactly the hot mop was damaged.

Thanks again.

Another picture. Note the line to the left at the top of the picture is a natural vein and not part of the crack. The crack runs from the center to the top right of the drain, and then down the left of the drain.

"If your (flat) slab was placed directly on the hot mop with thin set, there is the potential for cracking when weight is applied over any area with an irregularity, (high or low spot)."

I just confirmed with my contractor that indeed only thinset was used when the stone was placed. If the shower pan underneath is sloping (which I suspect it is) and no mortar was used, then maybe the thinset wasn't enough to support the weight? I'm sure the contractor and the soapstone installer will try to pass blame on each other here.

Do others think this could be the reason for the crack? I don't believe it was there when I first saw the stone.

The contractor definitely would have slopped down to the drain. One piece of soapstone cannot be "slopped", it would need to be cut into pieces (tiles) to slope correctly. The theory that it was placed on a slopping bed and then stepped on (causing the crack) seems extremely plausible to me. That they left it so and ran away is very troubling. That they tried to install it as a single piece is equally troubling. That the drain was installed by 2 contractors no working together, ditto.

(Hadn't seen your picture until now...)

Mongoct, how did you mount your shower bases? From your experience, would putting a solid slab on a sloped shower pan with thinset cause it to cave under pressure like this?

It could certainly do that.

For the ones I fabricated, the soapstone itself WAS the pan, the membrane, the drainage plane. So no additional membrane (like hot mop in this case) was needed.

The bottoms of mine were flat, they were set on a flat subfloor and bedded in thinset.

I've only seen a couple of hot mops (they tend to be a west coast thing), and they have been flat, not sloped. For your shower, if your hot mop was sloped and they filled on top of the hot mop with large glops of thinset, then set the soapstone over a significant thickness (greater than 1/2") of thinset, as thinset cures, it shrinks. That's why its called "thin" set. It's to be used in "thin" applications. For thicker beds, a medium bed material, something besides thinset, should have been used.

It is possible that your "thick" bed of thinset could have shrunk and created voids underneath if indeed your hoot mop was sloped.

My first phone call would go to whomever installed the soapstone pan, or to the GC if the soapstone was set by one of his subs.

Apparently, there was about 1/2" of thinset down there according to my contractor. This is all very disappointing. I've got a call in to the supplier/fabricator, but the supplier seems to be having a hard time getting their fabricator to give me a call. I'm not sure what exactly the arrangement is between them (they operate under the same name, Soapstone International, but I suspect that the supplier sells the stone to the fabricator at wholesale and subs the work out to them). The person I spoke with said it is the fabricator's responsibility to get this thing worked out. But I am not being called back, despite several calls and an email with pictures.

mongoct: SOME soapstones can be worked with woodworking tools, but hardly all. And the skill required to route out a single slab to the desired pitch is quite beyond the skill of anyone who would leave a cracked pan and walk away without so much as a word.

Also, shower pans, soapstone or no, have a dismal failure rate without a membrane.

Sorry to see this come up. The fact that it's cracked across the drain points to a problem with the installation rather than a flaw in the stone.
It could be excessive deflection of the subfloor and joists if not on concrete slab.
It could be deficiencies in the bed below the stone.

It's certainly worth escalating this to the upper management of the soapstone installer, if it appears they used the wrong method of installation. Or did your GC perform some or all of the preparation of the area to receive the slab? Unless you can determine a clear cause, you may end up negotiating a two- or three-way split with you and one or more of the other parties sharing the cost of replacement. Good luck!

The big complication is, someone could say that a different sub came in later and dropped something heavy on the floor, or that the crack was there when he started work. For others who are acting as GC, this is where inspection backed up with photos is necessary, before a different contractor is allowed in.

What is still not clear to me is whether the fabricator communicated any specific requirements about the install to my GC. I know for the vanity tops, they had a handout with their requirements listed. We got no such paper for the shower pan (they probably don't do many of these). There was, however, one conversation between my GC and the fabricator where the fabricator explained to him how they planned to install it. Unfortunately, at the time I was not aware of all the nuances of different substrates and was also trusting that these guys all knew what they were doing. I do not recall what was said in that conversation, but I think that is where the key to this blame puzzle lies. I doubt I will get anyone to admit guilt here. The fabricator is paid in full, the GC is not yet (only $1500 remaining, which might cover a new slab and fabrication, but not a proper repair, which would mean tearing out the entire shower bottom half).

What do folks recommend for a fix? A full replacement, tearing out tile, etc., or if there is space, putting a new slab over the existing one?

The soapstone fabricator is claiming that the crack was caused by someone "stepping" on the stone before the thinset was dry. That is impossible since my GC had to refill it with water for 24 hours to ensure that the shower pan below had not been damaged during the install (they dinged the tar hot mop underneath while installing). In any case, they are here now and have applied Wood & Stone Acrylic Penetrating Crack Filler, which presumably they plan to sand down after it is dry. They dumped lots of acetone on and cleaned and dried the area thoroughly. I know this does not get at the root of the problem, but what experience do folks have with how much this product will hide and seal the crack? The stuff is supposed to be water thin and able to penetrate into the crack.

Also, I discovered that my contractor had pictures from immediately after the install. The crack was there from the very beginning. So it either happened just as they were setting the stone, or right after. Whatever the case, they may have walked away from it at the time knowing it was there, and I wasn't there to see it. See pic. It is not as detailed, but the crack is visible in the same exact spot as the above pics.

Why did your contractor accept that?

I hired the soapstone guys myself. My contractor was on site that day when I wasn't able to be, but he wasn't responsible for their work. He doesn't have the greatest attention to detail, and the crack wasn't so evident that any of us noticed it until it was too late.

Curious as to what ended up happening? did the filler work? Are you keeping the cracked base?

Well, the crack filler did work, at least in filling/sealing the crack, although if you knew it was there before, you could still see it (but it looks more like a natural vein now). What they didn't do, which I understand is the proper way to do this, is mix some stone dust with their epoxy to camouflage it a bit.

At this point, with our baby arriving in a few days, I'm calling it good enough. I oiled it up which helps hide it a little more. Here are some pictures.

And here is another more close up.

It doesn't look bad and you're right. If you didn't know you probably wouldn't know. If it holds water and you're happy with it, then it sounds like you're about to have more important things to think about! Good luck and best wishes for you and your family!

Sometimes a contractor gets incredibly lucky. This is one of those times.

The repair looks ok.
Using an acrylic adhesive was the proper way to repair it.
As long as their aren't any voids(hollows) under the stone you should be fine. Don't be too concerned about using stone dust in the mix. There are many ways to do this and you will hear many different opinions from folks.
Your contractor did ok.
The big question with these type repairs in a wet enviroment is longevity.