Every home needs a strong foundation. If yours is settling, slipping or cracking, it may be time to call a pro.

Take a look around

"The most important thing for homeowners to do is look for simple signs inside and outside the house," say Ken Swain, general manager of A-rated Americrawl Inc. in Indianapolis. "If they see cracks in a brick home, a window that looks off-center, or some wood that's come apart, then they need somebody to evaluate the situation." Stairstep cracks along the bricks are common: "Any kinds of cracks in the bricks or outside the foundation wall are signs of some shifting or moving of the foundation."

An age limit

"If you have a home that's 90 years old, some settlement is to be expected," Swain says. "But if it's a newer home with some fairly drastic cracks, then that house isn't holding up very well." Joel Whitley, president of highly rated Whitley Engineering Inc. in Locust, N.C., agrees: "A quarter-inch crack on a 50-year-old house isn't the same as a quarter-inch crack on a two-year-old house."

The great outdoors

Look past your home and out to your yard. "We look at the trees," says Ed Sylvis, owner of A-rated Seismic Safety in Pasadena, Calif. "If a tree has an arch in its growth, that means the soil has slipped, and you might need to hire a soil engineer. It's called downhill creep - if you're on a slope and the soil gets wet, it expands downhill because of gravity."

Water, water everywhere

"As simple as it sounds, the main thing is to keep gutters clean," Whitley says. "Point the downspouts away from the house and make sure the yard drains away from the house all the way around."