I'm looking for advice on how to reinforce my attic, which was built back in 1926. The floor joists are spaced 16 inches apart and span 14 feet to each load-bearing wall. The attic isn't very stable; there's some sagging, and the lath and plaster ceiling have cracks. I'm uncertain whether I should sister the beams, block them, or do both. If I sister them, do they need to span the entire 14 feet, or can blocking help reduce that requirement? Is there anything else I should consider to make the floor feel sturdier? Thanks for any help!
2 Answers
Have you considered laying down some 3/4" plywood? It could help with added stability, but it seems like the beams might not be sturdy enough for that. It’s important to address the underlying issues before just throwing down plywood.
Sistering the beams is definitely your best option to add strength. Blocking can make the floor stiffer and reduce movement, but it won't correct the sagging issue. You don't have to sister the full 14 feet; just overlap a few feet on either side of the sag. There's an effective nailing pattern for this, but I can’t remember the specifics. Just make sure to look that up!
Ok, thanks for the tip! I'll definitely keep that in mind!
Yeah, I thought about plywood, but I'm worried it won't be solid enough. That's why I’m leaning more towards sistering the beams.