While giving a new $900,000 home a thorough going-over, Salt Lake City home inspector Kurt Salomon found a problem under the deck. The builder had cut corners, using the wrong kind of fasteners to secure the deck to the house. Yet, the municipal building official had approved the work.

"In some cases, a building inspector is not going to crawl underneath the deck looking at the hardware. A good home inspector will," says Salomon, past president of the American Society of Home Inspectors.

Because it uncovers aspects of the home that are unsafe or not in working condition, an inspection is a must when buying a home, says J.J. Montanaro, a certified financial planner with USAA.

"You want surprises that come with homeownership to be happy surprises, not bad ones," Montanaro says. "A thorough home inspection by a certified professional can help ensure that's the case."

Salomon says an inspection of the house you want to buy helps identify not only safety concerns and failing structural elements but faulty mechanical systems and areas that soon may need maintenance.

You'll pay around $300 to $500 for an inspection, which can take two to three hours. The cost can vary based on your geographic region, and the size and age of the home. Requesting other services, such as septic and radon testing, will add to the fee.

"An inspection is money and time well-spent," Montanaro says. "If your inspector finds things that should be repaired, you can use that report as leverage to have them fixed or negotiate a lower price."

To help get the most from a home inspection, Salomon and Montanaro advise you to follow these steps:

Do your homework: Many contracts include a home-inspection deadline, so start shopping for an inspector when you qualify for a mortgage. This gives you time to find a qualified, professional inspector.

Look for the inspection clause: Before you sign a contract, make sure it includes a clause that makes your purchase contingent on the findings of an inspection with the inspector you choose. This can provide a way out of the contract if the inspector finds a major problem the homeowner won't address.

Make sure the clause is included even if the contract specifies an as-is sale, meaning the seller does not agree to make repairs. "If a seller's not willing to let you inspect the house, that's a big red flag," Montanaro says.

Hire a pro: Shop around. Ask friends, neighbors and your real estate agent for recommendations. For help online, the American Society of Home Inspectors has a database of its certified inspectors. And the Department of Housing and Urban Development offers a list of 10 questions to ask inspectors.

Ask to see a sample report: Inspectors fill out reports, following checklists for different areas of a house. It should be clear and informative. Reports longer than 25 pages filled with lots of legal print - usually meant to protect the inspector against liabilities - raise a red flag. By the same token, a few pages aren't enough.

Accompany the inspector: Take notes and ask about maintenance issues you'll need to address, such as waterproofing the deck, caulking the siding, changing air filters and other matters.

Review the report: The inspector will send you a written report detailing his or her findings. Read it closely and ask questions to make sure you understand the condition of all areas of the home.

If your inspector finds a leaky roof, a faulty water heater or some other problem, you may have the right to ask the seller to correct it to your satisfaction or to lower the price. If the seller refuses, you may be able to break the contract without penalty.

If a seller agrees either to make the repairs or offer to lower the price, take the money and then fix the problems yourself.