Housejacked: An Unsettling Tale

· Scope out large trees. A slab foundation that does not go down beyond the water table (about three feet) may be affected by what's beneath. In our case, the only significant settling that occurred was in the non-basement portion of the house. Roots from large yet still growing trees often invade the soil under a foundation. Ordinarily this is not a significant problem unless there's a drought. In a dry summer, the trees soak up any water they can get, which further depletes the soil. As a result, the dirt compacts, causing the house to shift and settle. Shuster explained that soil around trees can shrink several inches, and even when the water table returns to normal, the ground will not regain its full volume.

Some cracks are seasonal; during the dry summer months, they expand, and during the wetter winter months they contract. Last summer, the longer we went without rain, the more our cracks expanded. In such seasons, keeping the ground moist, not saturated, can help prevent additional damage.

· Get the dirt on the dirt. In this region, many soils are prone to consolidation under the weight of a house. With gravelly or granular soils, settling tends to occur immediately. With clay, it takes much longer. Whereas old houses were generally built on whatever land the owners had, newer construction often involves fill soil brought from another location. It's important to ask whether the fill soil was uniform and compacted. If made up of different materials, the soil -- and therefore the house -- may settle at different rates. Also, if the fill was not tamped down, more significant settlement is likely as the house compacts the soil.

If soil is a concern, hire a geotechnical engineer for a soil study, which will provide the information you need to consider probable consequences.

Tallying Up the Damages

Most if not all of these problems can be fixed. The goal is to find out before rather than after you purchase your house, because permanent solutions are often time-intensive and costly.

"Get an objective determination of the cost, what is going to be required to mitigate the cost and how much that is in dollars," Shuster said. "The problem becomes identified, quantified by qualified personnel, and then it becomes a bargaining chip in the negotiating process."

While many structural problems are not within a homeowner's control, disclosing known problems is. Shuster noted that "there is a difference between a 'good face' and fraud." The trick is differentiating between the two.

We still have some cosmetic tuck-pointing work to do on the outside of our house, and the north side still slopes. At least now, however, we can officially call that character.