Found no subfloor under sagging floor
Fixing a flexing or bouncing floor often reveals that previous owners cut framing incorrectly, layered bizarre materials, or completely left out the subfloor. What begins as a simple attempt to secure bouncy panels with heavy screws quickly escalates into a massive project. Homeowners are often forced to pull up the boards or completely demolish and rebuild the area to create a stable surface.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Using shims with subfloor glue and adding cross supportsDid this help you?
- 2Ripping everything out and starting overDid this help you?
- 3Demolishing the middle of the house and rebuilding itDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Tried to secure the bouncy subfloor down with some heavy threaded screws. Got them to bite… but subfloor still felt like a trampoline. Figured I might as well bite the bullet and pull the two panels of T&G OSB subfloor up… there’s about a 1/2 inch of play because they ripped the 2x4 wrong.”source ↗
“A plank was starting to flex in our kitchen, and we were going to try to DIY it, but when we pulled it up we discovered we have no subfloor in our kitchen.”source ↗
“My buddy's bathroom floor was sagging. Previous owners were actual crackheads. We discovered the walls were covered in layers of painted linoleum over painted carpeting (yes, on the walls), etc. We stopped being careful and just demo'd the middle of his house and rebuilt it”source ↗
Where this came up
People with this problem also raised
- 5How to spot hidden subfloor damage covered by new OSB
- 2Finding construction debris and mystery layers under old flooring
- 3Staring at a hidden flooring mistake I can't unsee
- 6Why is my subfloor wavy and dropping?
- 4Can you put new flooring over old pine boards without a subfloor?
- 2Foundation vent won't fit because of rebar in the way