Hi all...I had a toiliet leak in my basement and have had to take up the vinyl and underlay and essentially gut the bathroom. The subfloor is 6" x 1/2" wood planks that run at 45 degree angle across the joists. The bathroom is 6 ft wide by 12 ft long. The long walls run in the same direction as the joists, meaning the walls are not anchored to the joists but are supported by the plank subfloor (I only inherited this, not build it). The plank floor is completely uneven and flexes when you walk on it. The flooring subcontractor says he will not guarantee a squeekless install. Normally I would cut out the plank flooring and replacing it with interlocking plywood or OSB. In this instance I see two choices but I'm hoping some of you will have a better alternative. First, cut out the plank subfloor along the wall a few pieces at a time and insert a braces between the joists to help support the wall (I don't know if this was done previously but from the nailing pattern on the floor I'm guessing no. As I go along, I can insert braces and support the walls. Second, leave the plank floor intact. Use a tile motar and run a coat of motar over the planks to even out the height differences. Before the motar dries, install the plywood or OSB. Run screws along the joists but not countersink. When the motor has set, I cna then countersink the screws. I've read on here that the wall should be supported on the joists so cutting out the subfloor should not be a problem. There is nothing square or plumb about this house...I swear it was made with scrap lumber! I would that if the joists are properly braced there would be nails in the subfloor but there are none. Photos attached. Thoughts? Ideas? Cheers Phil

Mudroom addition being built, slab on grade flush with top of foundation wall, 2x6 sleepers on top to match height of existing floor. Considering the sleepers will be pressure treated, is it okay to notch the ends at the sill plate so the joists lay flush against the slab, or should they rest on top of the sill? If they rest on top, I'll have a 1-1/2" gap between the sleepers and slab. Not necessarily a bad thing I suppose. Except there will be a step down onto the garage floor slab, so that 1-1/2" gap would need to be covered. Is what I have shown the best way to frame this area?