basement finishing

3 years ago I bought a 5 year old house that was custom built. In our city, floating basement walls are required. My question is with regards to stairs down to the basement. My stringers are supported on both sides by floating walls. The walls/framing on the top end of the stringers is supported by 2 large jack posts under the top of each stringer. However the bottom of the stringers are sitting on a 6" wooden platform. The concrete floor under this platform obviously has come up about 1/2 to 3/4" over the years and raised the platform and so pushed the stringers up (and the floating walls as a result). This has caused the floor around the staircase on the first floor (also the 2nd floor) to very noticeably rise as you go towards the staircase. Lowering the 2 large jack posts slowly a bit over time (9 months) has no effect on correcting the problem - the jacks appear not to be carrying most of the weight.
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My thoughts are to make a crossbeam near the bottom of the stringers and support it with 2 small jacks. Then remove the platform on which the stringers are currently resting on. Then over a long period of time (perhaps 1/16" every 3-4 weeks?) lower the jacks until the 1st floor is level again. Or should I keep lowering the jacks until the stringers are completely supported by the hanging walls only (and then remove the jacks)?
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Any comments/advice would be appreciated.
Thanks...Rick

Hey Rick,

Here's a reply from Joe Benedetto, President of ElkStone Basements in Denver, CO. If you click the "Reply" button instead of doing a quick reply, you can add images. So shoot us some images and I'll get Joe to elaborate further on this topic.

Hello,
It sounds like there’s a non-floating element (framing member) in your walls that is pushing up your landing and main level flooring due to your heaving floor. I think the root problem would be moisture content in your soil so I’d look at drainage around your house. But yes I think that your idea would work. If you can you send me some photos of your stairs before finishing I’ll review them.

ElkStone, Inc.
Joe Benedetto | President
direct 720.771.0718 | eFax 303.496.0054
http://www.elkstone.com