Angie's List asked experts from around the country about gutter cleaning, maintenance and the right time to repair or replace.

• Tim Bender, vice president, Arizona Energy Products & Raingutters, Phoenix, azenergy.com
• Mitch Reed, president, Leaf Filter NW, Tukwila, Wash., leaflessinseattle.com
• Rodney Darbonne, owner, Rain Mizer, Katy, Texas, rainmizer.com
• Sara Megonigale, co-owner, Gutterman Services Inc., Sterling, Va., guttermanservices.com
• Bruce Donatell, owner, Gutter Systems, Minneapolis

When should I have my gutters cleaned?

Bender: It's not as big a deal in Arizona because we don't have a lot of tall trees. If you do have tall trees, you'll want to clean them at least once a year.

Reed: Instead of having to regularly clean your gutters, we recommend buying a micro-filtration gutter guard. Here, a lot of pine and fir will stuff your gutters, causing gradual damage that will lead to expensive repairs later.

Darbonne: Anytime they get debris in them. As little as 10 to 20 pine needles can cover your outlet and cause water to overflow.

Megonigale: A minimum of twice a year. Homes in heavily wooded areas need it up to three or four times a year.

Donatell: Usually once or twice a year. But people should keep an eye on them. I've seen some gutters that went from clean to clogged in a couple of weeks.

What are the benefits of clean gutters?

Megonigale: Clogged gutters can cause a lot of problems with water damage, by allowing water through the foundation level, window wells or the roof line.

Donatell: If the water overflows, the soil around the house can absorb a lot of water, leak into the basement and cause mold.

How long should new gutters last?

Bender: Ninety-nine percent of the gutters around here are aluminum, which doesn't rust or deteriorate over time. Material warranties on those are about 100 years.

Reed: To maintain your gutters, clean them every year with a garden hose or a pressure washer, or brush the debris off with a long telescopic brush. The system should last a lifetime.

Darbonne: We give a 50-year warranty on the gutter and 15-year warranty on installation. It should last as long as the house.

Megonigale: You can expect 15 to 18 years with aluminum. Copper will last twice as long, but it's also twice as expensive.

Donatell: They should last 40 years. Aluminum can't rust, and the sealant I use is guaranteed for 50 years.

What is the price to clean, repair or replace a gutter system?

Reed: In the Pacific Northwest, most homes are fairly large, so the median cost for a typical new replacement gutter system, including a micro-filtration, will run between $3,000-$5,000.

Darbonne: We price according to the components, number of corners, number of downspouts, and number of stories and size of roof.

What other advice do you have for homeowners?

Bender: Make sure the person you hire knows what they're doing and is licensed through the Arizona Registrar of Contractors.

Reed: Beware of unlicensed, unbonded or uninsured gutter cleaners! If the contractor falls off a ladder and doesn't have insurance, you could lose your house in a lawsuit.

Darbonne: Make sure downspouts are not clogged. We just did a house where the PVC pipe connection to the downspout was clogged for years. At the corner of his foundation, there was a gap where water had eroded the concrete.

Megonigale: Sometimes installing larger downspouts can make a significant difference. Make sure your gutter is properly sloped when installed to avoid standing water.

Donatell: I believe a solid cover is very good. You pay a little bit more for it than a mesh cover, but it tends to keep the gutter more clean.