The M15 weighs 750# right out of the shower - that's (at best - when everything is equal) 150# at each point of suspension but it can and does go a lot higher on a single point if she swings out of balance. I've got a one car garage and little weight on the floor above it so the joists can handle that. You might do as I did the first time, lifted her a few inches above the trailer and slept on in (not in it!). The next morning she was still handing and there were no stress marks at any of the suspension points so I took her all the way up. The first time I ever had her raised at a boat yard, they used slings, did not secure them properly, and I almost lost her. That's when I decided I could do as well if not better on my own. Stan m-15, #177, Carol II