Crack in shower floor

JB Weld products or any 2 part epoxy.....Home Depot, Lowe's, etc.

For an emergency repair, use the CLEAR Gorilla tape. For us, it lasted several months. Get a home type rubberized bath mat to protect the tape from being pulled off. Cut the mat to fit and clear the drain hole. Then...

When you have the time to do it right, first get under the shower pan and support it correctly. This is a common problem. Manufacturers all seem to cut corners here, leaving that thin plastic to hang in space. I used some wood scraps, then filled in with Great Stuff. I used the low expansion type so as not to distort the floor. Then clean the inside pan and put a strip of Etenabond over the crack. The edges will bleed adhesive, so cover the Etenabond with the Clear Gorilla tape. Put the mat back down and forget it. Will last forever.

I agree with JB weld for just about everything, and it may well work here. But, that floor is always going to move when you stand on it, so that is why I went this route. It makes a permanent, waterproof, FLEXIBLE seal.

Good luck.

What material, ABS or fiberglass (I'm guessing ABS)? Can you reach under the shower (some have an access panel/cover)? How big is the crack? You should repair a crack in a floor properly not only so it won't leak, but to prevent it from cracking and opening up in the future.

Sometimes you need to drill a small hole at each end of a crack to stop it from growing. I'd suggest supporting the shower floor if you can reach under it so the floor won't flex by using a little expanding foam. Be very careful with foam that you don't use too much (use low expansion type). You might be able to inject some foam through the floor if you drill a hole at the ends of the crack. Shower pans & tubs in houses are often installed with mortar or expanding foam under them to prevent the bottoms from flexing and cracking but RVs lack this to start with.

If you can reach under, I'd suggest using a small thin patch of ABS or fiberglass and then a filler on top. A plastics shop should have sheet ABS material. Epoxy alone may work okay if you support the floor. There are pigments that can be added to epoxy if you want to try and conceal the crack, as well as for fiberglass. There are repair kits available at various places.

Yup, I forgot about drilling holes at the ends of the cracks. I'd do that no matter what method you choose. That's important. I also may have put Etenabond on the bottom, as well as the top. I really don't remember as it has been some years ago. Never a leak since then.

The key is to support the floor to minimize movement. Then decide on the cosmetics.

I have toi agree that pre planning is everything (supporting the pan correctly from underneath will be paramount to any successful repair. Mine was wonky until I got under it and actually built a support structure.

This pan did not crack for lack of support. which is common. It cracked due to impact. There are professionals that can fix it perfectly. Cost 150-200. Look up tub repair refinishers in your area.

I think you have to know the material its made out of.
A fiberglass resin kit will work for fiberglass but as suggested, its probably a plastic type. They do sell a plastic welder kit at places like Harbor freight but I have never used it to offer any advice.
People also use the JB weld , but I have never used it either.
I have always gone to a body shop for help with things like this, that might be an option for you.

There are plastic tub repair refinishers as Lantley said. We had a double wide put in at the lake several years ago. The manufacturer that made it had a chip in one of the tubs. We ask for a new tub. They said if we would let a refinishers fix it and we weren't satisfied they would replace it. After the fix we couldn't even find where it was and this was 10 years ago. Amazing job and you would never no it was repaired.

for a professional repair, you do need to know what the material is, but a professional repair should be done by a professional if you want it to look like it was never damaged.

for a permanent repair that will last the life of the rv, clean the area well with with soap and water,then wipe it down with alchol to remove any oils that may remain from either bodies or soap.... then mask the area off about a quarter inch around the hole/crack, and then gently buff it with an abrasive scotchbrite pad or 280grit sandpaper... then use a small dab of 3M 5200 adhesive sealent on it...
this will take a few days to cure, but it will be forever. then get some of the anti-slip flowers, turtles, or tape to place over it for double duty... it will help protect the patch job, and hide it so the repair will never be seen...

A new shower base is about $170, if it were mine, that cracked base would be replaced immediately. A failed repair could be a real trip spoiler.