I'm remodeling my upstairs bathroom with stone tile and I'm not sure my contractor is doing the work that needs to be done. I have 2x8 16" on center with an 11' 4" span. After some online searching by me, I found that 11'4" is outside the stone tile deflection. The tile place said it would be fine, but I mentioned it to the conractor. He had a guy add 2 more 2x8s under the bathroom floor. The way it was done, I'm not sure does anything. On one end, they rest on a basement wall that I don't believe is a load bearing wall. In the middle they are nailed to the existing 2x8x. On the outside wall side, there is an electric wire running, so he notched in from the side (about in the middle of the joist) about 6". The other one he cut out the bottom of the board so that it now doesn't rest on the outside wall. Did this do anything to help? I'm not handy and am getting worried, so any input will be greatly appreciated.