Hurricane Katrina washed ashore 1,000 miles from Ohio, but homeowners here can learn a few lessons from the storm.

The fallout from the 2005 hurricane season sent a clear message to homeowners everywhere -- don't assume that your homeowners insurance policy pays for everything when disaster strikes.

Yet, a disturbing number of homeowners nationwide don't know what is and isn't covered by their policy.

About 30 percent still think that flood damage is covered by a standard homeowners insurance policy, despite extensive coverage of flooding issues arising from the Gulf Coast hurricanes, according to a survey by the National Association of Insurance Commissioners.

Half think damage to water lines is covered, while 37 percent think broken sewer lines are covered. They're not.

Mold, termite and insect damage, earthquakes and injuries to pets aren't covered, either, even though many homeowners think they are.

"Some people take for granted that everything is covered," said Mary Jo Hudson, director of the Ohio Department of Insurance.

"Most people do more research to buy their car than they do for other important decisions such as what their insurance covers."

Taking your insurance policy for granted can be tough on the wallet.

In the case of an earthquake or a flood, you could "find out after the fact that your entire home has been damaged and you aren't covered," said Peter McMurtrie, chief claims officer with Grange Insurance.

Or your basement could flood and you could be left with no money to pay for the damage, he said.

Chances are there's a gap somewhere in your coverage that could leave you with an expensive repair bill.

"No policy covers everything," said Joel Brown, vice president of personal lines for State Auto.

Homeowners policies typically exclude damage from earthquakes, many types of water damage, war, nuclear hazards and neglect, according to the Ohio Department of Insurance.

No homeowners insurance policy covers flooding. Flood insurance can be purchased only from the National Flood Insurance Program.

Exclusions don't stop there.

Did you inherit Grandma's jewelry, silverware or fur coat? There are limits to what insurers will pay for these types of belongings and for some other types of claims.

For most policies, the only way to be sure is to read the exclusions page of your policy, Brown said.

The exclusions page is the detailed list of everything that your insurance company won't pay for.

Exclusions generally fall into three categories.

First are the big ones that are too expensive to insure, including "very big catastrophic events such as flood, nuclear, biological or chemical contamination," Brown said.

"If (we) insured them, the average person couldn't afford the policy."

Property damage caused by war, riots and chemical weapons falls into that category.

Then, there are the things that are excluded because they should be insured with a different, more suitable type of policy, such as cars or businesses.

Finally, there is damage that isn't covered but could be if you purchase a policy rider. A rider is additional insurance you can add to your standard homeowners policy, usually for a nominal price.

Think of riders as a way to customize or build your own insurance policy.

There are riders for sewer and drain backup, for the replacement cost of computers, antiques and jewelry, or for insuring home-based businesses.

You can also buy riders to cover earthquakes, fungus and dry rot, or to increase the amount your insurer will pay if someone is injured on your property.

The personal-property rider increases the amount your insurer will pay to replace the contents of your home, such as furniture and clothing. Most policies value contents at a minimum of 50 percent of the home's total insured value.

People with older homes might want a rider that will cover the extra costs of rebuilding the house to meet current building codes.

"The goal is to keep the policy affordable without forcing people to pay for an expensive policy that covers things they don't necessarily need," Brown said.

Not having any coverage isn't the only peril. You could also be underinsured and not have enough insurance to adequately cover losses in the event of a disaster.

About 59 percent of homeowners are underinsured, according to a survey by Marshall & Swift, a real-estate valuation firm in Lawrenceville, N.J.

Of those, the average home is underinsured by about 21 percent.

Homeowners often end up underinsured when they don't update their policies to reflect the value of renovations and home improvements, Grange's McMurtrie said.

"Typically, policies anticipate normal inflation," annually boosting coverage limits to reflect rising costs for building supplies, he said. They don't factor in any improvements you make to the house.

"The rule of thumb for renovations is anything beyond a simple deck, contact your agent," Brown said.

Policies should also be updated to reflect major life changes, such as getting married or divorced, an elderly parent moving in, having a baby or adopting a dog, said Mary Bonelli of the Ohio Insurance Institute.

A lot of homeowners make the mistake of getting just the coverage required by their mortgage lender when they buy the house and then never looking at the policy again, Hudson said.

Homeowners should review their coverage at least once a year to make sure it's up to date and provides enough coverage, Bonelli said.

Homeowners might also want to consider replacement cost coverage, which pays the actual cost to rebuild your house if it is damaged or destroyed, even if that amount is above the policy limit. It can be added to a standard policy as a rider.

Most standard policies have actual cash value coverage, which pays only the value of the house as it is now, which means the value is lower because of depreciation.

The difference between these two types of policies can quickly equal thousands of dollars.

Of course, all of these riders add to your annual insurance premium.

Some folks end up either underinsured or with gaps in coverage because they are reluctant to pay more for a product they hope they never have to use.

"Price is an important issue, but remember you get what you pay for," Hudson said. "If you want a less expensive policy, know that it likely has more limitations and understand what those limitations are."

Ohioans generally have it pretty good regarding insurance.

Ohio is the seventh least-expensive state for homeowners insurance, with an average annual premium of about $523. The national average is $729, according to the National Association of Insurance Commissioners. Rates went down about 1 percent in Ohio in 2006.

"It's because of our climate. We're a lower risk area," Hudson said. "We don't have (major) earthquakes or hurricanes, so more companies want to write here."

That doesn't mean Ohio has no perils. An ice storm in January 2005 caused $38 million in insured losses. In 2004, fires caused $319 million in damage, according to the Ohio Insurance Institute.

The only way to know what's covered is to read your policy and discuss any questions with your insurance agent, McMurtrie said.

"It isn't the most invigorating reading material, but considering it covers your most valuable asset, it's important."•

Sidebar: Check your policy

68 percent of homeowners think vehicles such as cars, boats and motorcycles stolen from or damaged on their property are covered.

51 percent of homeowners think damage from a break in the water line on their property supplying water to their home is covered.

37 percent of homeowners think damage from a break in the sewer line on their property that connects to their municipal sewer system is covered.

35 percent of homeowners think damage from earthquakes is covered.

34 percent of homeowners think damage from mold is covered.

31 percent of homeowners think damage from termites or other infestation is covered.

22 percent of homeowners think pets stolen from or injured on their property are covered.

Most standard policies don't cover the above.

Source: National Association of Insurance Commissioners