A co-worker just purchased a house that has a construction technique that I’m curious about.
I’m not sure exactly how to describe this, but basically the builders attached 2x4s to the sides of the house’s central support beam and then notched the floor joists and set them over the 2x4s. In effect, creating joist hangers.
Was this a common technique? I think the house was built in the 40s or 50s?
Also, the 2x4s appear to be slowly sliding down the side of the beam, taking the floor joists with them. Is this something that anyone has run into and what did you do?
Replies
That is a very common construction technique, resting joists on a ledger. Up until 20 or 30 years ago joist hangers weren't common, so if you didn't want joists running over the top of the girder, and you didn't want to mortise the joists into a solid girder, attaching a ledger was the only option.
Usually they're fine, unless they are seriously undernailed or the outside walls of the house start pushing out. Then they will fail the way you describe.
The fix is to jack up the joists to where they should be and re-attach them to the girder. Once the joists are supported, take out the ledger and replace with individual joist hangers. Or, re-attach the ledger and hope for the best.