Basement flooding can be a real source of problems for many homeowners, whether it comes from groundwater seepage or other issues. It can damage your appliances, make the sewer system back up, and cause damage to the structure of your home. The good news is that there are a few things you can do about it. These vary in how much they will cost, how much work they take, and what you will get out of them. There's sure to be a solution that will work for your basement and your budget.
Resources Step one is to take a look at your resources. Find out if you can obtain information about groundwater flooding from a building inspector, insurance agent, or local government office. You can also get in touch with the Home Builder's Association and Extension agents for your county. They can help you figure out the best solution for your situation and might even be willing to help you with low interest loans and grants. Don't forget to find out if your insurance covers the flood damage - while most plans do not, you may have a rider that helps in cases of water damage.
Don't forget to talk to a pro to find out about your options. Contractors can help you decide how bad the damage is and might be able to fix the problem quickly and easily. If you have serious flooding, you're probably looking at a bigger repair job. You may also be able to waterproof your basement on your own, as well.
Solutions The best solution for your situation is going to depend on how often water leaks into your basement and how bad the flooding is when water comes in. In cases where you get very minor leakage, you might want to start by putting furniture and appliances on blocks, or installing a sump. That's not going to stop the water from coming in, but it will buy you a little time and prevent damage while you figure out what you're going to do.
Once you're sure that everything is safe, it's time to find out where the water's coming from. In some cases, what looks like a leak is just condensation on a cold basement wall. To find out which one is the problem, dry part of the wall, and tape a sheet of aluminum foil to the dry area. Wait a few days, then look at which parts of the foil are wet. If the water is just on the side facing the room, the problem isn't one that waterproofing will fix. Add a dehumidifier to keep the water from becoming a problem. If you find water on the side of the foil that was facing the wall, you're looking at a seepage problem.
Leaks might happen because your house was built incorrectly in the first place, because the foundation has settled and there are now cracks in the basement floor or in the walls, or because there's water built up outside and the pressure is forcing it through the walls. Find out where the water might be coming from (groundwater, a leaky pipe, etc) and why it's coming into the basement. You may need to ask a professional to help you with this part, but sometimes it is obvious.
For instance, if the landscaping is graded toward the home, you might be getting rain runoff in your foundation. Waterproof your basement in this case by doing a little landscaping. Just add soil around the house so that water runs away from the house for about six feet. Double check your gutters, too. A missing downspout could allow water to get into your basement at an incredible rate. If necessary, put on an extender or splash block. Make sure you have enough downspouts, too - for every fifty feet of roof line, you need at least one.
If you've done all this and there's still a problem, it's time to take a look at the basement yourself.
DIY Waterproofing compound is available at most local hardware stores and can be used to fill holes and cracks in your basement floor or wall. Apply the waterproofing mixture directly to hairline cracks, but repair larger ones before waterproofing. A good rule of thumb is to clean out and patch any crack or hole bigger than 1/8 of an inch before waterproofing. A cement and sand patcher can easily be troweled in to fix most floors and walls. Waterproofer comes in two main types - premixed liquids that you brush on, and powdered waterproofer, which is mixed with water or a bonding agent before application. They require you to work quickly and may not work as well as premixed brands.
Read all instructions carefully before using any product - some require you to strip off paint. All walls should be dry and mildew-free before you put anything on them. You might want to add a mildew resistant paint once you're done waterproofing if mold is a regular problem. Apply waterproofing mixtures starting at the bottom of the wall and add two to three coats.
Contractors Sometimes you can't just do it yourself. If your leak is a big one, you might need to talk to a professional. Get someone who's willing to do a thorough inspection and explain what they are going to do in detail - ideally, you want a written estimate from a licensed, insured contractor, not just someone a friend knows. A good contractor could make a huge difference in how dry your basement ends up being!