We're planning to build a tiny house with the living room cantilevered 20" over the trailer tongue. There will be 3.5"x3.5" floor joists 24" o.c. supporting the cantilever, and they will have 7'-long clear spans between the ledger beam and the wall posts/studs. (See images, below.)
The above image also shows how a 20" bumpout over the trailer tongue will help support the middle half of the cantilevered floor. The living room floor will be 10' wide, and the bumpout will be 5' wide.
My question is whether the bumpout plus the floor joists will provide sufficient support for the cantilevered living room? Or should I also add a pair of knee braces to the corners of the cantilevered floor? If I need knee braces, then should I construct them with 2x4s, 4x4s, or something else? (See image, below.)
The cantilevered floor will support a 6.5'-high (at the peak) gabled wall, so it won't be load bearing except at the two ends (where the knee braces could go, if necessary). The rest of the cantilever will support a wall of closets, so fairly uniformly distributed, static weight. The roof probably will have 6" eaves and 6" rakes. Any more information needed? Thanks for any advice you can offer.