I'm looking at reinforcing a steel frame under an old mobile home in order to place it on a concrete foundation, essentially transforming it into a house over time.
The steel frame consists of two 12 inch box frame beams that run the length of the trailer, and are situated close to 3 feet back from the outside edge. There are 12 inch steel plates with offset flanges running between the main beams and located every 4 feet. Outriggers run out from the main beam to the outside edge and they taper to nothing. There is noticeable sag of the floor, due to the lack of support from the outriggers. To make matters worse, the floor built over the frame is built of 2x6's that run the length of the unit, and not across.
My plan is to notch through the main longitudinal steel beam where they join the cross members to facilitate a new beam (consisting of two 2x12's) that will but up with the cross beam (and will be bolted in place). This beam will run from one side of the trailer to the other, and will become the new support beam. It will also be bolted in to the longitudinal beam using angle iron to temporarily hold everything together. I would continue to install these wooden beams at every 4 foot location, one at a time. All of the beams will be tied together with a doubled up 2x12 along the side as well. This new structure will provide better support for the outer wall and allow me to rest the entire unit onto a concrete foundation. (ie the support is shifting from concrete piers located 3 feet in to an exterior foundation)
I know it's a lot of work, but is a worthwhile project in my case. Does anyone see a problem with the structural integrity of this plan?