Structurally unsound decks
Repair cost: $2,000 to $10,000
Salomon sometimes finds homes with structurally unsound decks built by do-it-yourselfers or inadequately trained workers.
"Every few years, you'll hear a story on the news about a catastrophic deck failure with fatalities," he says. "Usually, it turns out that the deck was just nailed together -- almost like a kid's treehouse."
Contractors who build decks properly will use special ties, metal brackets, screws and other materials. Amateurs or insufficiently skilled pros often won't.
Repair cost: $1,000 to $2,000
Radon is an odorless, colorless radioactive gas created by the breakdown of uranium that often exists naturally in soil, especially in areas with lots of granite deposits.
The U.S. Environmental Protection Agency estimates 6% of all American homes have dangerous radon-gas buildup, which can cause lung cancer after long-term exposure.
Home inspectors or house hunters can easily detect the substance using radon-test kits that cost about $10 at hardware and home-improvement stores.
But even though effective radon-removal systems run about $2,000 or less, Salomon says positive tests will often send home buyers running for the hills.
"It's usually not a question of the dollar amounts involved, but of the emotions involved," he says. "Radon gas can kill people."
Another way to prevent problems with your home is to check out MainStreet's look at 10 Things Your Contractor Doesn't Want You to Know!