I just bought a house with a majorly notched floor joist under the tub, causing the floor to sag by about a quarter inch. I want to lift the joist back to level and sister in full span 2x10's to ensure stability down the line. I've already consulted a structural engineer, and they gave me the green light on this plan.
Now, I'm trying to figure out what size bottle jack to use since I've never done anything like this before. I'm thinking a 20-ton bottle jack might do the trick, but I wanted to check with you guys for any advice. The local joists span 14 feet, are spaced 16 inches apart, and I can access them from the basement. They support a tiled bathtub, one toilet, a ~12-foot interior non-load bearing wall parallel to the joists, and a ~30-foot interior load bearing wall that runs perpendicular to them, supporting the second story.
I've even noticed some stress fractures in the drywall of the non-load bearing wall, which adds to my concerns. The roof is rafter type, meaning the exterior walls take most of the weight, so the joists aren't critical to that load.
I'm aware of some steps I need to take, like using a thick metal plate between the jack and the post and making sure the force is applied steadily and correctly. Still, I'm open to any insights from those who have tackled this before. Thanks for the help!
1 Answer
From my experience in construction, I've seen folks use smaller bottle jacks, like the ones you have for cars, for these types of jobs. They'd raise the floor a bit and then add temporary posts to secure it in place before sistering the joists. The size of the jack really depends on the load you're dealing with, which varies greatly based on your home's specifics. No one here can give you a precise answer based just on the info you provided. Honestly, a 20-ton jack should be more than enough for what you're doing. Just trust your gut on it!
Those are some valuable 2 cents, thanks man.