Guess what guys... they finally called me back! I looked into the other methods you had mentioned to contact the company, but I couldn't find the CEO's number and since the only number I had was a 1-800 number I didn't think I could do the phone trick (or maybe I am wrong and didn't understand). But I kept on calling them leaving them messages about how I would need to return it if I didn't hear back
But anyways, I kind of got bad news. They say they test all their tubs up to 300 pounds, but would not recommend them being used for any weight above that. So they have no opinion on mortar, etc, for a bed for the tub. However, I am not going to return the tub, I have done too much work on the tub based on this tub's measurements (cutting overflow/drain to fit my tub, cutting out walls based on tub size, ledger installation, etc). And I'm assuming all steel tubs are probably rated at 300 pounds anyways. I still don't want to go and get a cast iron tub since that will be too heavy to install for me in that tight space (I am a one man team), and in addition, I feel with the weight of the cast iron tub and the weight of the 425 pound man would result in the floor possibly needing to be reinforced.
I still want to install this steel tub, but I should add reinforcement to it. I was thinking of doing this: Cutting wood and shaping it to fit the base of the tub and creating a rectangular shaped structure to go around the foam pad on all sides. I would cut the wood so that there would be a gap between it and the tub, and in that gap I would pack it with some foam padding I bought from Lowes to allow the tub some "give" with weight and to soften the way the wood feels to the tub. I attached two pics to show you what I mean. The first one is of the tub's foam pad, the second one explains more of what I want to do.
I have talked to a few tub installers with my concerns before I got this call about the tub's weight load, and many of them said that a 425 pound man should be okay. So I'm assuming it will be okay. I don't think steel really cracks, but I know it can bend, which is why I want to install additional reinforcement.
So what do you guys think? Is my plan for extra reinforcement using wood and foam padding good?