Spring is prime time for home repairs -- and that makes it prime time for outright scams or frustrating disputes. You can take action to avoid both problems.

Home repair scams by traveling con-artists work like this: Con-artists stop at your door, give you a hard sell, and offer sensational low prices. It might be for roofing or painting, tree-trimming, or asphalting your driveway with material supposedly "left over" from a job nearby. The con-artists insist that you pay in advance -- but they do little or no work and never return. Remember, legitimate contractors very rarely solicit door-to-door. Be skeptical. The main rules are to check out a contractor, and never pay large sums in advance to a contractor you don't know. Help older neighbors who might be pressured or intimidated into paying traveling con-artists.

A few 'bad-apple' local contractors also take large advance payments but fail to do the work, or do just part of a job or very shoddy work. This is hard to prove as fraud, but it's costly and frustrating. Follow these tips to protect yourself when you hire a contractor:

• Beware of high-pressure sales tactics such as "today-only" discounts, offers to use your home as a "display home" for replacement siding or windows, and "lifetime warranty" offers that only last for the life of the company. Always get several written estimates -- shop around for the best deal before making such a large investment.

• Check out a contractor before you sign a contract or pay any money. Request local references -- and check them out. Contact the Attorney General's Office to see if it has complaints (call 515-281-5926, or 888-777-4590.) Contact the Better Business Bureau (515-243-8137, or www.bbb.org.) Contact your county clerk of court and ask how to check if a contractor has been sued by unsatisfied customers.

• Get it in writing. Before any work begins, agree on a written contract detailing work to be done, responsibility for permits, costs, and any other promises. Ask for a copy of the contractor's liability insurance certificate. Put start and completion dates in writing, and consequences if the contractor fails to meet them. (Example: the contract could be nullified if the contractor doesn't start on time.) If you sign a contract at your home, in most cases you have three business days to cancel.

• Avoid paying large sums in advance if you don't know the contractor. If you have to make a partial advance payment for materials, make your check out to the supplier and the contractor. Insist on a "mechanic's lien waiver" in case the contractor fails to pay others for materials or labor.

• Be very cautious of credit or financing arranged by a contractor. This is an area of serious abuse by a few contractors in Iowa who arrange credit with high-cost lenders. Such loans may have high interest rates, steep up-front fees, hidden costs, and even costly brokers' fees. Be wary of offers to incorporate credit-card debt or other debt into a second mortgage. Check first with your attorney or a local lender you can trust.

For more information or to file a complaint, contact the Attorney General's Consumer Protection Division, Des Moines, Iowa 50319. Call 515-281-5926. The Attorney General's web site is: www.IowaAttorneyGeneral.org.

Click here for Consumer Advisory on "Asphalt Paving Scams."