A question was asked re 12 inch long cracking in the floor of acrylic tub see question link below :
https://www.askmehelpdesk.com/plumbing/acrylic-tub-33480.html

I recently bought and installed an acrylic tub during an overall upgrade of my bathroom Unfortuneately a week after installation I did a web search which showed that there were complaints about long cracks on this tub which is supplied intergral plywood reinforcement in the tub.

User letmetellu submitted a very good reply to above link with a comment at end end of reply that the crack could be repaired. Could user letme tellmellu if the repair can be made on deep cracks that might result in leaking.

When I worked for a manufactured home/modular home dealer and we had complaints of cracks in the tubs the factory would send out a repair crew with a brand new tub and replace the whole shebang. The factory didn't bother trying to repair the crack and when I asked the service manager at the factory he replied that it was easier to just replace the tub as in the past when the tubs were repaired the repair didn't hold and the tub ended up having to be replaced.

Would consider contacting the tub manufacturer and complain to them about the crack as it's basically unfixable with any repair that would last for more than a year.

A question was asked re 12 inch long cracking in the floor of acrylic tub see question link below :
https://www.askmehelpdesk.com/plumbing/acrylic-tub-33480.html

I recently bought and installed an acrylic tub during an overall upgrade of my bathroom Unfortuneately a week after installation I did a web search which showed that there were complaints about long cracks on this tub which is supplied intergral plywood reinforcement in the tub.

User letmetellu submitted a very good reply to above link with a comment at end end of reply that the crack could be repaired. Could user letme tellmellu if the repair can be made on deep cracks that might result in leaking.

While Letmetellu claims to be a shop owner he doesn't give the best of plumbing advice. Here's part of the post you coppied
. There are things that you can put under the tub to give it support, one is the expanding foam that is use so often around windows and doors
This is incorrect! The foam consists of air bubbles that will give I'm time under the weight of the water and a persons body. The only way to bed a tub is with mortor or cement.
He also stated,
The crack in your tub can be repaired, in fact the bottom could be cut out and support put in and the the bottom replaced.
Bottom cut out of the tub? That's a new one. He might have been referring to a tub reliner but who knows? You don't cut the bottom out of a tub to install a reliner. But reliners are pricy.
Let's talk about repair.



One way to repair acrylic or fiberglass baths is to install a liner. This essentially relines the entire bath area with a new, inner bath area: a pocket inside a pocket. Or you can tear it all out and install a new shower or bathtub.

Fiberglass/acrylic repair kits are a sort of lesser option--but certainly much cheaper. They allow for spot-repair of cracks and holes that may have been plaguing you, much in the same way one might repair a boat or car. In fact, one company that makes shower/tub repair kits is Bondo, best known for its automobile body repair compounds.
How Do Fiberglass/Acrylic Shower Repair Kits Work?
It's not difficult, though the odor can stink you out. The basic method is so:
Clean the areas to be repaired thoroughly. Make sure all cleaning products are off the surface before you begin the repair.
Apply a special fiberglass tape to the cracked area.
Mix resin, hardener, and tint together.
Spread compound over taped area, smoothing it as carefully as possible.
Allow compound to harden.
Sand down surface.
How Does It Rate?
Fiberglass/acrylic repair kits are a good stop-gap if you plan on a complete repair or relining in the near future. But you're almost sure to be disappointed by the repair job. Tints come in basic one-size-fits-all colors, like white or almond. Your shower/tub surface will never quite match the repair compound. Bondo's tub/shower repair kit is cheap and lets you get the job done in a day. (Buy Direct - Bondo #20186 Tub/Shower Repair Kit) Don't look to Bondo for any customer support, though. Their main product line is still cars and boats, and they pretty much ignore their home repair llne. You might also check out Bath Wizzard.
If you elect to repair the crack you should really bed the tub before you do it. A fiberglass or plastic shower stall or bathtub should be bedded, which means support is required under the base so the floor does not flex or give when someone is standing on it. If the unit is installed without proper support then in time the drain seal will rupture and cause a leak. Putting cement or mortar under the floor when it is installed gives it a solid platform , which prevents flex in the floor. Simply puddle or make a ball of thin set, cement or mortar and place them around under the tub and bear the drain. Without this support, the flex will cause movement at the pipe connection resulting in cracks in the base and leaks at the drain.
Good luck in whatever you decide. Tom

We always install light-weight concrete or mortar under tin or acrylic tubs. If this is not done - my experience tells me - the bottom of the tub will always crack.

When I worked for a manufactured home/modular home dealer and we had complaints of cracks in the tubs the factory would send out a repair crew with a brand new tub and replace the whole shebang. The factory didn't bother trying to repair the crack and when I asked the service manager at the factory he replied that it was easier to just replace the tub as in the past when the tubs were repaired the repair didn't hold and the tub ended up having to be replaced.

Would consider contacting the tub manufacturer and complain to them about the crack as it's basically unfixable with any repair that would last for more than a year.

.
Removing a tub in a modular would be easier than my home with a tiled wall etc. butin the long run removing would lekely be the best thing to do.

Thanks very much for your/reply it was helpful Bob Scot


While Letmetellu claims to be a shop owner he doesn't give the best of plumbing advice. Here's part of the post you coppied
This is incorrect! The foam consists of air bubbles that will give im time under the weight of the water and a persons body. The only way to bed a tub is with mortor or cement.
he also stated,
Bottom cut out of the tub? That's a new one. He might have been referring to a tub reliner but who knows? You don't cut the bottom outta a tub to install a reliner. But reliners are pricy.
Let's talk about repair.



One way to repair acrylic or fiberglass baths is to install a liner. This essentially relines the entire bath area with a new, inner bath area: a pocket inside a pocket. Or you can tear it all out and install a new shower or bathtub.

Fiberglass/acrylic repair kits are a sort of lesser option--but certainly much cheaper. They allow for spot-repair of cracks and holes that may have been plaguing you, much in the same way one might repair a boat or car. In fact, one company that makes shower/tub repair kits is Bondo, best known for its automobile body repair compounds.
How Do Fiberglass/Acrylic Shower Repair Kits Work?
It's not difficult, though the odor can stink you out. The basic method is so:
Clean the areas to be repaired thoroughly. Make sure all cleaning products are off the surface before you begin the repair.
Apply a special fiberglass tape to the cracked area.
Mix resin, hardener, and tint together.
Spread compound over taped area, smoothing it as carefully as possible.
Allow compound to harden.
Sand down surface.
How Does It Rate?
Fiberglass/acrylic repair kits are a good stop-gap if you plan on a complete repair or relining in the near future. But you're almost sure to be disappointed by the repair job. Tints come in basic one-size-fits-all colors, like white or almond. Your shower/tub surface will never quite match the repair compound. Bondo's tub/shower repair kit is cheap and lets you get the job done in a day. (Buy Direct - Bondo #20186 Tub/Shower Repair Kit) Don't look to Bondo for any customer support, though. Their main product line is still cars and boats, and they pretty much ignore their home repair llne. You might also check out Bath Wizzard.
If you elect to repair the crack you should really bed the tub before you do it. A fiberglass or plastic shower stall or bathtub should be bedded, which means support is required under the base so the floor does not flex or give when someone is standing on it. If the unit is installed without proper support then in time the drain seal will rupture and cause a leak. Putting cement or mortar under the floor when it is installed gives it a solid platform , which prevents flex in the floor. Simply puddle or make a ball of thin set, cement or mortar and place them around under the tub and bear the drain. Without this support, the flex will cause movement at the pipe connection resulting in cracks in the base and leaks at the drain.
Good luck in whatever you decide. Tom

Thanks for you reply. The acrylic tub used had four very low pads at the corner of the tub for support. I am only now asking the question since there is no complete support in the center should I not have had additional center support such as wooden supports boards or mortar in the center of tub.

Thanks your reply was a big help both he option of a tear out, cement support and the repair info will be kept just in case I forget.

Thanks again Roert Steel


We always install light-weight concrete or mortar under tin or acrylic tubs. If this is not done - my experience tells me - the bottom of the tub will always crack.


Thanks for your reply re light weight concrete.
It was only wo weeks ago I had a bathroom upgrade, The acrylic tub used had with four very low pads one at each corner of the tub. Even though light concrete seems the best way, the question I am thinking about is :- would an additional board slipped under the center be a good idea. Thanks Bob Scot

Even with the support legs - we still install light-weight concrete. It gives tub solid support and when you step into it, it feels like stepping on solid block of concrete floor. No buckling, no chance of cracking no sounds of water hitting bottom of the tub like hitting an empty barrel.

The acrylic tub used had four very low pads at the corner of the tub for support. I am only now asking the question since there is no complete support in the center should I not have had additional center support such as wooden supports boards or mortar in the center of tub. Would an additional board slipped under the center be a good idea. It would be a better idea then nothing. Just make sure the board's snug against the bottom of the tub floor. In addition I would puddle some mortor or cement around the drain to protect the drain seal. Good luck, Tom

It would be a better idea then nothing. Just make sure the board's snug against the bottom of the tub floor. In addition I would puddle some mortor or cement around the drain to protect the drain seal. good luck, Tom

Thanks again for you opinion. The problem now is to get access to under the tub as the only access is from the kitchen ceiling. I can see to floor boards the tubis resting. So it will be tricky removing a few of the boards to get access to slide the additional board in place.

Thanks again for your very helpful suggestion/input. Unfortuneately my wife switched the supply of the tub from enamel to acrlyic without confirming the change with me. I still love her very much. Bob Scot