[yoda911]

Billy,
The screws go all the way through. On the bathroom side I used large washers to spread the load and putting the screws all of the way through the support using carpentry nuts that are pressed into the support, these screws ended up being 3 1/2 inches above the tub. Since the walls are so flimsy, I opted to add vertical supports to relieve most of the strain on the screws so that the screws are just holding up the support, the weight of the step is actually being supported by the vertical supports. Right now the vertical supports are just wedged in between the floor and the horizontal support. For safety I will probably end up gluing and screwing them in place. The problem with these supports is that they are below the edge of the tub so I will probably use rivet screws there. I think there are a dozen different ways this concept could be utilized. I just opted for what was easy, functional yet still visually appealing. I also thing if more weight needs to be supported, additional or more substantial support options could easily be added.
Hopes this helps Billy