Help! Is this a big deal? I mean it is, but is it a “fix this asap, you’ll have to remove everything and start over” or a “seal it asap, and don’t worry about it.”
We have four cracks (heading NSEW) in our downstairs shower all aiming towards the drain area and starting at the edges of the shower. I do not remember seeing them before, and there is definitely both evidence that someone else regrouted, and that the regrouted grout (but not the original grout) is coming up. We don’t actually use this shower much, but it’s in the guest room, and we have guests for the next two weeks.
I don’t think you’ll know if there’s a pan until you tear out the tile. There’s supposed to be a water proof pan, but who knows if whoever tiled the shower used one. The cost of being wrong is pretty high, so I’d error on the side of caution.
Looks to me this is a serious issue. At one time, my tenants reported ventilation issue and have replaced with good exhaust fans.
If I guess right, there may not be any ventilation at the bath or less ventilation or exhaust is not working issue.
Same home had similar issues, crack started forming. The tenants left it as it is as they did not notice. The cracks, if I guess, would have formed by humidity (without ventilation).
In six months, all the side walls started falling apart…I was forced to change sidewalls,…everything almost bath renovation costed me appx $10000.
I do not want to give you panic statement. Look at this angle and try to fix asap. Perhaps, elt1 or ptiemann provide more info - if they know similar issue.
I may not come often this blog, due to many personal issues, suddenly noticed your posting.
Tile is not water proof, and neither is grout or even solid concrete.
There should be water proofing under the tile, the 2 common choices for custom showers as yours are “shower liner” (here is a photo: Robert Lamoureux: Hot mop vs. vinyl shower pan liner, bathtub shell – Santa Clarita Valley Signal ) or hot mop (which is basically cooked tar applied with something that looks like a mop). “Non-custom showers” like in apartments use a precast plastic tub.
I would say it’s a cosmetic issue, it is not going to cause water ruining your wooden sub-floor (unless the water-proofing membrane fails), but it makes you wonder why the tile is cracked.
Under the liner should be a mortar bed, which defines the slope. I think your tile is kind of big for a shower floor. Maybe the slope of the mortar bed is not even enough for such big tile.
Normally, if there’s cracked tile, I would think that the floor has flexed (was not stiff enough). But with a mortar bed on it, I don’t think that’s possible.
Look in the crawl space and look for leaks.
Test for leaks. Block drain and fill with a couple of inches of water. See if it holds water for an hour. No leaks no problem. Shower pan still waterproof.
This was my thought as well. And these tiles seem to be easily crackable. I’ve got some similar larger tiles that have cracked along a line which I"m guessing is where the plywood sheets meet.
The one by the drain hole makes perfect sense to me. Some one heavy steps on it and adjacent tiles. Stress risers incur and crack initiates from there and propagate in several directions. For now I will seal it to keep water from seeping through. Looks like cosmetic to me. You need eventually replace all as it is difficult to find identical tiles. If the subfloor is cement it is from ground settling or shrinkage.
I agree the direction makes sense–and they all four aim towards the hole. What I see from the crawl space is wood. I’m guessing 10"x2" beams–whatever they used in the 1960s.
Put a level measure the bubble direction. I suspect there is a or two vertical movement(s) from supporting beams buckling the subfloor.
ref. Positive bending moment.
I guess that’s really what I’m most worried about is that it’s leaking under.