Over time dirt, grime, and even mildew can build up your house siding. You can clean off these deposits using a pressure washer, which can be rented from most hardware stores. The key is to use a lower-pressure nozzle to avoid damaging the siding. A cleaning solution made with diluted liquid detergent works well on especially dirty siding, but if your siding is only lightly soiled, water alone should do the trick. You should always spray the siding using a downward angle to avoid shooting water up between the spaces in the siding. If you are not a do-it-yourselfer, you can find a pressure washing professional to do the job for you.

Aluminum and Vinyl Siding Repairs

At some point, your house siding might require some repairs. Aluminum siding can get dented when objects such as stray basketballs hit it. Vinyl siding is susceptible to cracking in the winter because the cold temperatures make it more brittle. Also, vinyl siding can melt if you lean something very hot against it, such as a barbecue grill lid. If a panel of your house siding is damaged, it easily can be removed and replaced with a new piece that has been cut to size and locked into place. In general, it is much easier to repair vinyl and aluminum siding than wood siding.

Though you will not escape maintenance duties entirely with vinyl or aluminum siding, they offer a worry-free and attractive exterior finish for your home.

Source: http://www.guidetohomeimprovement.com/siding/servicearticle/cleaning-your-vinyl-siding-or-aluminum-siding.jsp