A view of some of the notched Joists. Joists are 1-7/8 x 8-3/4, and these were notched about four inches deep. The two by four was possibly added as a means of providing additional bracing? If that was the thinking, it would not have made any difference.
Close up of one of the notches... Acccck!
Amazing what one finds when tearing out bad renovations. A very slightly damp, and oily IKEA style floor mat, vintage 1984? And some otherwise unidentifiable fabric...
One of the more severely butchered joists, about 6-1/2 inches removed, to accommodate 2" waste, plus hot and cold supply, plus 5 inch HVAC pipe... Acccck!
Beginning to fix up the disaster... 3/4 thick ply braces (about 6" x 24" or so were glued and screwed to 'clamp' the butchered joists in their current (thankfully they had hardly deflected) position. Then 2x6 blocking was installed between each sandwiched joist, about an inch from the parged interior wall.
A view of the beginning of the repair job, all joists sandwiched by 3/4" ply plates, and then blocks installed between all joists.