If you're a homeowner, you probably already know that a cracked foundation is no laughing matter. The discovery of wall cracks, doors that won't shut properly, and floor separation immediately makes us fear we may need foundation repair.

But how do we really know if our home is in danger? Well, first you have to determine the cause of your home's cracks. Here are a few of the main culprits:

• Expansion- Block, a popular material found in most homes, naturally expands throughout its lifetime. When coupled with overexposure to sunlight, block walls may begin to crack. The additional heat causes the block on your home to grow at a faster rate. Typically, the sides of your home that see the most sun will develop vertical cracks due to thermal expansion. If your builder didn't use adequate control joints, the damage could get out of control.

Underground block walls crack for different reasons. While below-ground walls never see sunlight, they do have to deal with water, perhaps the largest cause of foundation cracking. Earth pressure also may cause horizontal cracks in your underground block walls, signaling the need for foundation crack repair.

If you have cracked block walls, it may not necessarily be a sign of a serious problem. However, it's a good idea to call a professional to diagnose the symptoms.

• Shrinkage- The natural tendency for concrete to shrink causes the majority of foundation cracks. These cracks generally occur early in life of your foundation. The severity of shrinkage cracks depends on countless factors such as humidity, water, and type of concrete mix. Whatever the cause of your concrete shrinkage, the contraction leads to stress build up. Unless your builder placed control joints throughout your slab, the building compression may result in the need for foundation crack repair.

Shrinkage cracks may seem sporadic or discontinuous. They tend to taper off and start back up in the same general area. These cracks often run vertically or diagonally, originating in the corners of the foundation. You may notice some evidence of shrinkage near the corners of windows as well.

While shrinkage cracks may not continue and ruin your foundation, they may allow water to penetrate and cause future damage. To determine the severity of your shrinkage cracks, contact and expert on foundation repair.

• Settlement- Foundation settlement is every homeowner's worse nightmare- the one that requires a high dollar prescription. These settlement cracks occur when one portion of your foundation settles differently than another due to differences in soil, tree roots, or various other factors.

The cracks formed by incorrect settlement usually appear much wider than shrinkage cracks. Often these cracks expand more towards the top. This signals that one portion of the foundation settled more than the other, causing part of the slab to break and drop.

While foundation repair can solve your settlement crack problem, it's important to identify these cracks early to prevent serious damage.

Depending on the cause of the cracks you've found, your home may need foundation repair. While repair of deep settlement cracks may prove pricey, you can't afford to let them linger. The risks of further damage, basement collapse, and the devaluing of your home far outweigh the cost of dealing with the problem.

Unfortunately, pinpointing the source of your problem may prove a difficult task. The solution? Don't try to figure it out on your own. Call a professional to assess the damage you've found. They can find the cause of your problems and let you know if you need foundation repair. There's no time to waste!