Floor Joist Treated Or Not

He sees it all the time.

Floor joist treated or not.

Remember that treated pine is only slightly more expensive than regular pine. Floor joists in crawl spaces are closer than 18 to the ground. So i don t know. And you thought this was going to be easy.

Yes pt lumber can be used for framing including floors. Deck joists rotting from the top edge down because the deck boards and debris keep them damp for weeks after rain. But my friend wasn t. 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.

The joists were pressure treated lumber so i was surprised at how badly decayed they were. Usually when a joist gets sistered the new lumber does not span the entire length of the old joist. It is important to jack this end level to keep the floor from sagging any more and to keep the joists from splintering later. This treated lumber is bolted to the foundation and the floor joists typically rest on it.

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. The joist hangers used in construction with both sawn lumber and manufactured joists are usually galvanized zinc coated. Had started to rot on top of the joists due to the trapped moisture under the decking. Photos 1 and 2 show galvanized steel joist hangers supporting nontreated.

I finished a free standing deck a few weeks back and used ss deck screws ss hangers even ss hanger nails. 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. If there is a doubt then use pressure.