toilet area framing
 

http://i25.tinypic.com/nvcw0i.jpg

Plumber says I need to reinforce the floor before I put the floor back in.

The red line idicates where the joist would run had it not been cut out for plumbing. I was thinking a two 2x4's nailed together running from support "A" to "B" with a notch cut out for "C" where the joist would have been.

Would this work? Is there a better way?

thanks,
derek

Hello Derek:
You are on the right track but I would want to make it a little more beefed up. I would begin by doubling the joists at A and B, then suspend double 2 X 6s to hold the center up. I wouldn't make any notches at all, that is the trouble already.
My plumbing friends love their Sawzalls and sometimes get a little carried away with them; heating men are not far behind them.
Glenn