Usually when a joist gets sistered the new lumber does not span the entire length of the old joist.
Floor joist treated or not.
If there is a doubt then use pressure.
It is important to jack this end level to keep the floor from sagging any more and to keep the joists from splintering later.
Drop girders or beams that set in a cut out of a foundation wall should not have to be treated as long as they have a barrier between them and the concrete.
But my friend wasn t.
The allowable stresses of pt lumber are lower than non treated lumber which means it can not span as far.
Not all floor joist lumber has the same strength and even wood of the same species but of a different grade will have different strength characteristics.
Floor joists in crawl spaces are closer than 18 to the ground.
The joists were pressure treated lumber so i was surprised at how badly decayed they were.
The joist hangers used in construction with both sawn lumber and manufactured joists are usually galvanized zinc coated.
Because of this the tail end of the new lumber is not supported.
So he has two rot fighting tips for deck owners and builders.
He sees it all the time.
I finished a free standing deck a few weeks back and used ss deck screws ss hangers even ss hanger nails.
So i don t know.
Photos 1 and 2 show galvanized steel joist hangers supporting nontreated.
Yes pt lumber can be used for framing including floors.
Had started to rot on top of the joists due to the trapped moisture under the decking.
Also pt lumber is corrosive so connections need to be such that they resist corr.
On a related note i had to replace some deck joists a while back on a 8 year old deck in ct along the shore.
And you thought this was going to be easy.