House Wrighting Without Headaches

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There's no getting around it—the footing and foundation of your house are essential to its structural well-being. Even so, footings are sometimes insufficient and foundations poorly laid or out of level. Soil settlement, caused by construction over uncompacted earth or lowering of the water table, can damage even good work, as can excessive moisture brought on by poor drainage. And mortar joints in older brick foundations can succumb to age, freezing, chemical assault or any number of exposure-related miseries.

Support posts beneath the home's interior are even more likely to fail over the years. They may warp, then bend under pressure. Often, wooden posts are set on a dirt floor with no footing to transmit loads. If the weight doesn't sink them, rot and insects usually will. A thin basement slab is no substitute for a sound footing, either... especially if it's constantly moist.

The object is to find out—and fix—what caused the problem to begin with. If the source isn't obvious, consider calling in a contractor for advice. Never leave the question unsettled, or you may be back making the same repairs in a couple of years. By then, things will probably be worse.

Before you can start, you need to acquire a few tools of the trade. Professional house movers can use high-tech hydraulic jacks to coax any home to whatever level they please. But one-time housewrights have to get by on the bare minimum to keep costs in check. Borrow, if you can, two 10- or 12-ton hydraulic pump jacks, each with a threaded cap shaft and a 6" stroke. For a single-story house, 6-ton units should be sufficient. Heavy-duty screw jacks, operated by rotating a handle, aren't as convenient but will function just fine. For light work in tight places, you might also consider locating a small scissors jack like the kind used for imported cars.

If you're working in a basement, you'll probably need one or two temporary jack posts, or "red-heads," to support a beam that requires several columns. They're generally rated at 7 to 9 tons capacity and are adjustable from 6' to 8½' in height. The best ones have a threaded cradle at the top for fine tuning, yet shouldn't cost more than $30 or so.
Finally, don't go house-jacking without a 5' or 6' pinch bar, a crowbar and some kind of flat pry bar. And even the most meticulous individuals would be surprised at how often healthy determination and a hefty sledgehammer come in handy.

In this case, you'll be jacking from directly below the beam, so the process is straightforward. If you have a sound continuous footing but part of the internal foundation wall is damaged or missing, carefully remove a small section of bad wall and chisel any mortar debris from the surface of the footing at that point. Lay a pad on the concrete, set your jack so it's perfectly plumb, and place a shim block between the jack cap and the beam. Then raise the mechanism just enough to take some load off the sagging girder. When it's time to actually jack the beam, limit yourself to ¼" of lift per day, and don't raise the member any more than what's needed to slide the support under it.

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