Hi. First post here for me.
Recently bought a Grade 2 listed cotswold stone cottage C.1780
I have first floor joists in a bedroom and landing area that sag around 4 or 5 inches over a 3.7m span. They sit on a substantial oak beam around mid way across which appears in reasonable structural condition. And on limited inspection the joists and beam are on good footings with the walls. There's no real damp and minimal evidence historical woodworm. There are a few plumbers notches in joist tops and some small wiring holes.
The floorboards are junk but I'm not worried about them as I'd like to board out the two spaces ready for carpeting.
The sag is a problem because it means the doors and drawers of freestanding furniture open themselves and the cats roll to the middle of the room when they sleep.
I was thinking of ditching all the floorboards, sistering new joists to the existing ones, and plyboarding over. However it strikes me that with sag this big the new joists will almost be above the level of the old ones in the middle, so wont be fixed very well if at all to them.
Has anyone dealt with a similar problem? What did you do?
I don't want the upheaval of jacking the existing joists straight. They spent nearly 250 years becoming bent and I don't image they want to be straight again. Plus I don't want to disrupt the lath and plaster ceiling as it is in pretty good shape (albeit mirroring the sag).
Cheers