In article ,
says...
My plumber tells me it's OK to take out any one floor joist, is this
true?

The floor right now is 16" on center, span 8'6" joists 2"x8".

Assuming it's common pine, that's Barely adequate. Too
light for my taste.


If I understand right he wants to cut out about 18" from the center of
one joist and add doubled 2"x8" braces before and after to the
neighbouring joists.

I'm not certain if I understand your description correctly,
but the only way to get away with this is to create a "box"
around the drain area that ties the cut joist back into the
adjoining joists. In some cases, the joist to be cut should
be supported while the process takes place.

I'd have expected to double up the 2 neighbours but he says this isn't
needed.

Again, given that they're only 2x8's, I'd be tempted to add
some strength as well.
--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.