Existing whrilpool tub not on mortar?

I have a whrilpool tub that I'm having issues with caulking. I've caulked the tub about 6 times in the 4 years I've been in the house. Every time I caulk it, the caulk is good for a few weeks but then begins to fail. I've tried several different caulks and I've even had "professionals" caulk it for me. Always the same result. Today, when I was at the hardware store, another person overheard me talking to the sales person. The guy said that he was having the same issues with a tub he had. It turned out that the contractor that installed the tub never put down a mortar base. With out the mortar base, when ever they got into the tub, the flex of the tub pulled the caulk away from the wall, causing the caulk to break. I think this may be my issue as well. So, being the fact that I'm not at all inclined in areas of plumbing, here are my questions. 1. How do I tell if the tub was properly installed in mortar or not? 2. Assuming the tub is NOT properly installed in mortar, is it possible to get the proper mortar under the tub with out having to remove the tub? If so, How?

Thanks in advance!

You just have to find someway to see under the tub to tell if it's on mortar or not for sure. You might get an pretty good idea by just walking/standing inside the empty tub to see if there is flex, but that might not tell you for sure. If you do need to add support, you might consider Armstrong's Self Leveling Floor compound. It's made for pouring on to cement floors to make a thin, level coat for putting down vinyl flooring, but if you can devise containment around the tub, you can pour this stuff and it will flow under the tub. I would likely harden with cracks, but it will work. I did this for a fiberglass shower stall I installed in my basement, and it worked very well. It will find any crack or opening and ooze out, but I found some temporary caulking with strips of old towels worked pretty well, then after it was set, a chisel around the edges took care of the rest. This comes in large bags and you mix it in a 5 gallon pail. I used a paddle on my VSR drill and made short work of that!

3 sides of the tub are against walls in the bathroom. I'd say that it was installed in an alcove, but if that's the case, my entire master bath is just an alcove! The 1 side of the tub that points towards the room has a plastic side on it that I can pull off. When I pull it off and look under there, what am I looking for? Space between the tub and the floor? It wouldn't supprise me at all if the owners of the house before me did a self install and didn't do it properly. That's been par for the course on my house so far... everything has been half @$$ed.

Empty space. Legs. Supports. Whatever is holding the base.

You might want to contact the manufacturer who will help you figure out what additional support you could add now.

david

Actually, there has to be a way to access the motor, etc. Look in there and I have to guess that you can see down to the base (mortar or sub-floor), etc. From there you should be able to figure if it was done. Good Luck,

Pete

In the meantime, you can try using 100% silicone caulk. It's more flexible, more durable, and more waterproof than the acrylic latex caulk you've probably been using.

Also, it seems to me that you should be able to tell if the tub is moving when you get in it. Look where the caulk has come away from the wall, and move around a little bit. Does it look or feel like the tub is "flexing"?

New Update

I looked at the side of the tub this morning that faces the room. Removed the "side panel" of the whirlpool tub (I mind you, this is just a single person whirlpool tub, nothing really bigger then a regular bathtub).
I see around the base of the tub is foam. Like, who ever installed the tub, actually used the PACKING MATERIALS from the tub box. I assume that the tub came in a box with 2 large peices of foam for protection and they just used the piece that the bottom of the tub sat in as a base rather then putting in mortar or shims. Unless using the packing foam this is a common pratice.
So, now knowing that the tub "base" is nothing more then packing foam, what are my options? Do I need to pull out the tub so that I can get that foam out?


Thanks again in advance.

Verdeboy

Yes, when I stand say at the back of the tub, I can see the lip of the back of the tub pull away.

Some manufacturers bond foam to the bottom, and if it is sitting flat on a floor, works fine. If the floor isn't level or flat, or there is floor deflection, then you need to add material under it to both make it level and strong enough to not deflect. Your floor could be fine, but the installation is not. If you see the tub deflecting, the caulk seals will not survive. You need to get the tub fully supported.

Are the tub lips sitting on bracing? This is a requirement for any tub I've seen as well. If not, then the edges are just flapping in the breeze. They need to be sitting on a ledger board.

some foams are very rigid

having said that, i do think it is wise to cut it out and put whatever support you think will work to eliminate all movement. If you do not feel comfortable judgin "what will work", get other people to see the situation. A meticulous handyman, a few friends, a carpenter, a bathroom remodeler. They will all have different ideas about what is "good enough". Be sure to tell them that the caulk has pulled away after every new application, and that you want to stop the base from moving even 1/16". Otherwise they won't have the benefit of your diagnosis.

david

edit: now that i see Jim's post, i concur that the side rims too have to be looked at, and if they are not solidly suppported, then they too will need support. Note that the weight of the tub rests on the base and not on the sides. Always. The rims need a little support since the tub when full of water will push the sides out a bit (or a lot, depending on the tub's geometry), and that is why the rims need a ledge to hold them.

I'm pretty sure that there is some kind of bracing that the sides are sitting on but I'm not 100% sure. I'll have to take a look tonight and see.

Thanks again all, I'll post my findings later.

We just installed a whrilpool that is surrounded by three walls (a nook).
We had to put stringers for the edges of the tub to rest on, but not to do weight support. We also had to put a 50 lb bag of mixed mortar under the tub base to support the tub weight.

In fact, our install manual specifically stated that the tub would flex too much if there was not a mortar bed. They said to not use foam as well.

So I'm guessing whomever originally installed the tub forgot that step or decided to not do it.

I'd do what I could to get that base supported or someday a part of the tub could crack from continued flexing every time it is used.