My daughter is in the process of buying her first home and she paid for an inspection. The inspector found that the joists under one of the bedrooms in the center of the house that sits on a basement foundation is sagging. We both have been told this is very easily fixed however I feel like she is getting ready to buy a problem. There are one inch holes drilled along the walls of the entire basement foundation and the ENTIRE underside of the floor system was “conveniently” covered in black plastic to where the inspector could not observe the flooring of the entire house. I have been researching and feel like it’s possible that the seller is trying to cover up at least termite damage if not something worse. Does anyone have any advice regarding this type of issue or had experience in the repair of?
Flooring – Sagging Floor Joist in House Built in 1925
flooring
Related Solutions
Since you can get to the floor from underneath, you can shore up the flooring by adding new joists between the existing ones. This will not be a FUN process, but the process is simple enough, just labor intensive.
First, add cross braces between each joist at each end, of the same dimensions as your existing joists. You'll want them to be snug fitting between each joist, and well supported with joist hangers.
Now, between each brace, halfway between each existing joist, hang new joists to fit between the cross braces you added. Before you permanently hang the joists, prop them up from beneath with 2x4 temporary posts to force the tops up to be level with the tops of the existing joists (pushing the flooring above back into shape), then secure them permanently in place with joist hangers.
Add blocking between the old and new joists as well, to ensure the new joists don't warp/twist.
See the pic attached to help clarify what I mean
- Black = OLD work already there
- Red = new cross bridging or bracing
- Blue = new joists
- Green = blocking to prevent warping
- Purple circles = places where you use joist hangers
I certainly would not lay the flooring down over an unprepared floor. I have done this and the flooring ended up splitting, cracking and making noise. I would reinforce the flooring and make it level with floor filler prior to laying the new flooring.
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Best Answer
It's not unusual to see sagging floor joists on houses that are nearly 100 years old. Sagging joists can be adjusted with jacks, then permanently supported with a wall in the basement (or knee wall in a crawl space). This sort of thing is often best done by professionals though, because if done on your own too quickly you can cause other damage, or if done without permits, it can become a liability to a future sale of the property.
Black plastic may have been added as a vapor barrier over under-floor insulation, the 1" holes may have been part of a radon remediation effort. In other words don't jump to conclusions about fraud.