"If you have a house, you're going to have cracks," says Tim Ringer of Ashland Hardware. Not the most comforting of news perhaps, but if you've been worrying about cracks in the walls of your home, there may be some consolation in knowing that you're not alone. Ringer says he regularly fields questions from customers wondering what to do about cracks.

The big question, of course, is whether these cracks are a sign of a potentially serious and costly structural defect in your home. In most cases, the answer is no. Cracks occur in houses for one simple reason: houses are built from a combination of materials, some of which move and shift around, while others are stiff and inflexible.

The internal framework of most houses is made of wood, and wood is a surprisingly dynamic material. When humidity is high, the wood in your home absorbs moisture and swells. When the humidity drops, wood shrinks and contracts. The overall motion of any one piece of wood over time is fairly small, but the effect is magnified in places where several pieces of wood join; especially in frames around doors and windows and in roof trusses.

Most wall surfaces, on the other hand, are made of materials that are relatively rigid. The wall surface can't bend and flex with the wood, and after a while your walls begin to split or crack to accommodate the motion underneath. "Older houses with plaster or stucco walls are the worst," says Doug Walker, a retired licensed general contractor in Grants Pass. "Drywall is usually a bit more forgiving." The most common places to find interior cracks are over the corners of windows and doors; places where the settling and shrinking of wood is most noticeable. These cracks are usually vertical or diagonal, and rarely cause a problem more serious than a door or window that is difficult to open and close at certain times of the year.

Walker says the cracks that cause the biggest headaches for homeowners are the ones that occur on the outside of your home. "The exterior of your house is the "envelope" of the home. When that envelope is breached, water can leak in, and that can lead to some serious problems. You really want to be vigilant about repairing these types of cracks." Walker recommends taking time every year to walk around and inspect the exterior of your house. Be sure to check areas around window trims, decks, and where any slabs meet the house. He says these are the most common places for exterior cracks to occur. Caulk and paint any cracks you find and you'll save yourself a lot of trouble down the road.

Cracks inside your home are generally easy to repair. Don't be surprised, though, if the same crack reappears in a few years. "One of the most common questions I get asked is, 'How do I keep this from happening again?'" says Ringer. "Next time you do an interior crack repair, buy a fiberglass mesh, self-adhesive joint tape to use on the job. It's more flexible than regular joint tape, so it gives a bit as the house shifts and moves. V-groove the area around the crack and apply the tape. Then, trowel in some spackle," which Ringer says is more flexible than joint compound. "When that's dry," says Ringer, "prime the area and paint."

A simple and elegant solution to an all-too-common household repair!