Properly built baths have none of the issues that you describe. Inserts are the lowest of the low in both quality and function. Get something built properly, by a qualified contractor.

Yes you can get the 3 piece from Maax with the interlocking system that works very well .As for the ceiling part probably not going to happen with a 7’ ceiling I do not agree that acrylic surrounds are all cheap looking and they certainly have come a long way IMO They function exactly the same as tiled tub and shower . I have nice one in my home that was brand new when we bought and we decided to spend our money elsewhere in the renovation. I have had many clients that are just not prepared to spend their money on a tiled tub/ shower with very lovely looking and functioning bathrooms. I will say if I ever did my bathroom again I would probably do porcelanosa wall panels instead of tile I really like cleanability in a bathroom and the fewer grout lines the better IMO

Will you be gutting the bathroom? Yes, you can get multi-piece acrylic shower and bath sets that can be quite waterproof. A contractor would be able to take a look at your bathroom to see if any one-piece sets will fit in the door.

I just got off the phone with a manufacturer who sells higher quality inserts, and I am quite disappointed. He informed me that for multiple-piece inserts, silicone sealant is required where the pieces interconnect, and I asked him if black mold or mildew can grow on silicone sealant, and he said he's never heard of such a case.

I am very skeptical. We have used "100% silicone caulk" in our bathroom and it took only 2 months to start growing mildew all over it and looks disgusting. Correct me if I'm wrong, but I don't believe a mildew-free caulk or silicone sealant currently exists. I would love to be proven wrong about that.

What can I do now? I am stuck. I cannot accept a situation where I can expect to start seeing mildew growing in 2 months in a new bathroom.

Wow, that sounds like a nightmare. And extremely unhealthy. Sealant is not the problem here. Your mold problems come from water that’s either coming from inside the bathroom or from outside. Possibly both. You need a qualified contractor to pull the whole thing apart and identify the sources of leaks. I understand why you think a one-piece unit will help, but it’s not going to solve the underlying issue. If your floor is “recently sagging,” the joists may be rotting at this point. It’s hazardous and needs more than a band-aid.

Has the sagging floor been checked out by a contractor? Do you have an exhaust fan for the current shower/bath?

Definitely; we will be doing a pretty good gutting of the bathroom to fix all the leaks. I believe there's a lot of rotted wood to replace.

The water is mostly coming from inside, from when we take showers. After a shower, the water just sits there and does not evaporate all the way and does not drain away. Such as on the window sill in the shower stall. And in the corners of the bathtub. And even though we use PVC shower liners, there's always at least a little bit of water running down the outside edges of the bathtub onto the floor.

Also, the fixtures in the bathtub were never sealed up 4 years ago when we had the last contractor doing some partial remodeling (except of course for the drain). We didn't realize that might be a problem until recently...

After we gut it, replace the rotted wood, fix all the leaks, get rid of the leaky window, etc, I'm still skeptical about the mold problems. It's a tiny bathroom with a 7 foot ceiling that sees 2 showers a day. Even though there is a powerful vent fan that works great, there's still residual humidity and tons of initial condensation such that there's big beads of water running down the walls. All of the walls. I have put a dehumidifier in there, which helps, but does not stop the mildew from growing on the 100% silicone caulk.

Also, part of the humidity problem (or maybe a lot of it) is being caused by the fact that we keep the door to the bathroom closed all the time, year-round, and we do not have central heat and air, so the bathroom gets really hot and humid in the summer and really cold in the winter. DH does not want to keep the door open; he has read stories of snakes that come up out of the toilet through septic system. We are on septic.

So I guess, after reading this post again, our bathroom problems are more complex than I thought. Writing it all out really does help.

The bathroom door has a 1/2" inch gap at the bottom which supplies the bathroom with fresh air from the rest of the house while the vent fan is running, but other than that, there is no HVAC for the bathroom. We know the vent fan works very well because it clears bad smells completely in under 5 minutes.

We typically run the vent fan for 2 hours per day. Beyond running it 24 hours a day I'm not sure what to do about the situation. We know we are not going to install central air in this house, as the cost of such an installation cannot be justified by the home's market value.

The vent fan isn't going to do enough in a humid climate and with a house that has no AC. You've created a swamp that has fostered a mold situation that is driving you crazy and probably making you sick. The orange stains that you see are likely also mold related (well, it's a bacteria, but commonly called "pink mold.") Keeping the door closed is only exacerbating the situation.

scottie mom, The house does have 2 AC window units, but it doesn't have a central air system that is circulating air and bringing it through floor vents.

I have started a separate thread regarding HVAC problems, now that the issue has been brought to my attention by this thread. I will return to the insert vs tile issue once I figure out our HVAC situation. Thanks everyone for your input; I find it extremely helpful!

I’m glad you are addressing it! And glad it’s helpful. Best of luck to you :-)

IMO the vent is not working you need to turn it on before a shower and run for at least 1 hr after a shower . Where is it venting to? I had a client that when we started her bathroom reno we discovered her vent had been venting into the attic it got rid of smells unfortunately not humidity

I have a small bath with no windows or ac... Make sure the vent is run to the outside and that it did not disconnect somewhere. Try to tone down the heat of the shower you take... Warm the room in the winters - if it is very cold and you take a hot shower that will cause such steam! The water will run down the walls because the temp change is too great. If I do take a super hot shower and things look a bit damp - I just take a towel and wipe things down quick to help it dry out.

Get an exhaust fan with a humidity sensor that can install inside the shower - it will run til it's done.

The Modular shower units are very nice and durable IF IF IF installed properly.

Here is a nice one:

I have lived with septic all my life ( over 50 years ) and have never had a snake come out of the plumbing. And if you don't think they can't get under a door...well...

Your space needs a full gut and start from scratch... it will all work out in the end.

Good luck to you!!

You can add a through-the-wall fan that blows air from a hallway into the bathroom up near the ceiling and run it 24 hours a day.

If you are in an area with serious snake problems, you may want to consult a snake-removal specialist to find ways to make your house and septic system area less attractive to snakes. Hardware cloth (metal mesh) screens can be installed at some potential entry points.

When you install your new tub & surround, you might consider a window like this:

https://binged.it/33FtoB9

High enough for privacy but still will allow steam to escape.

I wish I had some kind of solid surface panels in my shower. Grout is the bane of my... well at least of my showering existance.

I'm thinking about solid surface too. But it looks like it would cost more than an insert.

Try acrylic panels.

Debbie Washburn, do you have a source for the surround in the picture you posted? It looks great.

That unit is from MAAX... they make nice stuff

Thanks, Debbi, I'll take a look.

Alright so now we know what we will be doing about our HVAC, so it's back to this issue.

We live in the hot humid south. Proper HVAC will certainly help, but will not completely eliminate the problems we face in this climate. There are many things I could get away with if I lived in a dry climate that I simply cannot get away with here.

I need a fool-proof, moisture-is-never-gonna-be-a-problem, low-maintenance solution that will not fail in 10+ yrs. I have been looking into tile one more time, but I found that you can always expect that tile will leak, sooner or later. Even if your foundation starts out perfect. So that's out.

Custom shower pans scare me due to potential moisture problems and wicking, and acrylic or fiberglass shower pans would require caulk where the walls meet up with the pan, which I don't want. So what are my options in this situation? Just an insert?

Panels, I looked into those, but that would require caulk where the panels meet with the pan or tub.

Tile will not leak if done properly. Schluter has a Lifetime Warranty in fact. Many other systems will give similar performance. 7-9K later with the right contractor, and you can be confident in the results.

Acrylic panels are not a problem, if done properly. 3-5K for redoing using a high quality system with the right contractor.

Solid surface is not a problem, if installed properly. 8-10K, with the right fabricator.

Everything will require caulk or some form of sealant at joins and in corners. Caulk isn’t an issue, when done properly.

Nothing beats having an appropriate exhaust fan installed that will get rid of the moist air that causes the problems. Nothing replaces proper air movement and the dehumidification created by the correct HVAC. Absent that, even the best completely non porous Corian surround in the world can grow mold and mildew on the surface. Because mold and mildew feed on the byproducts of using the shower: moisture, skin cells, soap residue.

https://www.ceramictilefoundation.org/find-certified-tile-installers

The only option I can possibly find that does not require caulk would be a one piece stainless steel shower...not very practical but wouldn't need caulk. I actually have been in a house where the previous owner had been a metal fabricator and installed a stainless steel shower in his basement. It looked like new although it was probably 40 years old by that time.

It is good to think about the maintenance issues associated with the various options but don't let the tail wag the dog. Spend as much time and effort on finding the right contractor as you do choosing your materials and your shower project will be fine.

I don't think an acrylic shower insert is your answer. MAAX and a few other companies make excellent products, but they all have the same limitation. The walls must be plumb and meet at nearly a perfect 90 degree angle. Otherwise, they look botched.

I doubt your bathroom can meet this criterion. Be cautious of quick fixes, they usually don't last very long, and unless you want to do it all over again in 5 years, look for a quality solution.

Without knowing more than you have disclosed here, we would approach the problems one by one like this:

1. Level the floor. There is some structural issue here that needs to be fixed first. Tile the floor only after it is level and has "rested" for at least a week.

2. If the existing tub is in good shape, check to see if it is level in both directions to about 1/8". If not, take it out to find the problem. It's probably the floor, but be sure. Fix the problem and reinstall the tub, or install a new tub.

3. Use semi-vitreous ceramic tile for the shower surround. Tile is forgiving of even major issues with walls that are not plumb and/or do not intersect at exactly a 90 degree angle. With the new urethane grouts, glazed tile is virtually maintenance free, especially if you add a little fungicide to the mix. We use a marine grade fungicide made for boats. Never had a mildew problem.

4. You can also tile the ceiling, but this is probably overkill. Two coats of a stain hiding primer like Kilz followed by two coats of a good acrylic enamel (semi gloss) is very washable and a lot less expensive.

5. Replace the existing window with a good quality vinyl window. Ordinarily, I hate vinyl windows, but in showers they are perfect -- water has absolutely no effect on them. Have your tiler return the tile to the window and slope the stool slightly so the water runs off. Caulk where the tile meets the window for a watertight envelope.

6. While the exterior walls are open, replace any existing rock-wool insulation with fiberglass batts or, for better results, blown-in closed cell foam or cellulose. Foam and cellulose, in addition to insulating, seal off any small holes that are the source of drafts.

7. Install a minimum 300 cfm working fan vented to the outside. It should be on a time delay switch or, better yet, a moisture-sensing switch that keeps the fan on until all the excess moisture is gone. This will take care of most of your mildew problem, the fungicide will take care of the rest.

Good luck with the project.