Every year, you go through the garage and chuck out the old, rusted bicycle parts and the broken garden tools. But if you really want to clean up that space, concrete cleaning is a great way to make your garage or driveway look like new.

How Deep is Your Clean?
The first thing to determine when you're taking on a concrete cleaning project is how big of a job you have on your hands. Will a light once-over do the trick, or will you need to call in the pros for some of those really tough stains? There are three basic levels of concrete cleaning:

Concrete Cleaning for Sealing Purposes
If your concrete surface has been previously sealed, you might need only a light cleaning using one of the methods above, and a touch-up or reapplication in highly trafficked areas. But if the surface has ground-in grime, tire tracks, oil or grease, then you should remove these stains before sealing. In order to do this, you have to penetrate the surface. Try one of the following:

• Degreasers: Several brands of concrete degreasers are on the market. They work by softening and lifting hard-to-remove, oil-based substances. You can buy them at contractor supply houses—be sure to specify that you need it for cleaning and stripping concrete. Also, be sure to follow all safety instructions on the package.
• Acid Etching: To clean deeper stains in your concrete, you can hire a professional to clean with diluted muriatic acid. This will take care of even your toughest stains, but it may alter the texture of your concrete surface.

If you do use these chemicals, pay attention to the disposal requirements in your area. Many places won't allow you to drain chemicals into storm drains, which means you'll have to make special arrangements, or hire a professional to do the job for you.

Colored Concrete Cleaning
If your floor or driveway is made from colored concrete, be sure to check the manufacturer's recommendations to be sure what will work best without causing any damage.

Concrete Overlay Prep
If you are preparing to add a decorative overlay to your existing concrete surface, the concrete has to be free of any sealers, coatings, cures or other materials, which could keep the overlay from bonding properly to the surface. The best way to remove these contaminants completely is a process called shotblasting, in which small steel pellets are fired along the surface. This will remove many substances very quickly. For a job of this magnitude, you will need to call in a concrete-cleaning specialist.

Most of the time, dirt builds up slowly and gradually on concrete surfaces, but scheduling periodic cleaning is an effective way of keeping your home exterior looking as good as new.