Messages and Online Forum Q&A

Re: House leveling

From: info@builderswebsource.com
Category: Foundations and Basements
Remote Name: 63.198.181.43
Date: 14 Aug 2001
Time: 08:09 AM

Comments

You have a 500-square-foot section of your home with a sagging floor and need to re-level it. You indicate that differential settlement may be as great as 6".

First, before going to the trouble of re-leveling your floor, you need to get to the underlying cause of the settlement. A 6" drop is huge and is indicative of a severe soils or structural problem.

Depending on the period over which this settlement occurred, it's possible that some of your joists or girders have deformed in the process. Raising the floor may result in other problems if you're not careful.

Jacking up a foundation requires skill and experience in this specialty. A mistake here could result in serious injury or structural damage to your property.

However, if you insist on doing this yourself, you can get hydraulic jacks or corkscrew jacks to place along key support members. Use thick pieces of plywood under the jacks (such as 1-1/8") to help dissipate the load across the ground. Gradually raise the jacks a few fractions of an inch per day -- over a period of time. With each raising, let the house adjust to the new position. We recommend no more than 1/4"-1/2" per day. You'll hear plenty of creaking as the framing adjusts. You will likely need jacks in a few areas to spread the load across the beam.

Once you've reached your final level, you'll need to pour proper footings and provide suitable support posts for the floor. Again, you need to understand why the house settled in the first place and take measures to prevent it from happening again.

Finally, we urge you to have a licensed professional do this for you. Stories abound of injuries or fatalities resulting from a collapsing structure. Furthermore, with a 6" drop as you describe, you have a serious foundation settlement issue that may need other remedies, including underpinning or supplement supports.

Let us know how your project proceeds. In either case, don't be surprised if you have to fix plenty of interior cracks as well as readjust doors and windows that are out of plumb. Good luck!

Builders Websource

Article Tools

Builders Websource® is a corporate member of ASTM International—a non-profit engineering body dedicated in part to the standardization of building materials specifications, products, systems, and test methods for improved health, safety, and reliability of residential and commercial structures.

Copyright © 1999 - 2008 Builders Websource®, an InBuild™ company. All rights reserved.