Water intrusion can wreak a great deal of havoc in the home. A serious roof leak may leave you with warped floors, peeling paint, ruined furniture, and an enormous repair bill.

If your roof is in good condition, it will provide a stout defense against heavy rain. However, you'll also want to make sure your roof deck is secure to protect your home against severe weather.

The roof deck is the surface where shingles, metal panels, or other roofing materials are secured. The deck is often made of sheets of plywood or other lumber fastened to the rafters in the attic. Knockout Inspections, a company in Fairhope, Ala., says no roof deck is continuous and there will always be seams between these building materials.

When these seams aren't sealed, they offer a path for water to enter your home. This is particularly likely during hurricanes or other storms, which can tear shingles off the roof and leave the openings exposed to wind-driven rain. The Insurance Institute for Business & Home Safety says an unsealed roof deck allows up to 60 percent of the rain that falls on the exposed surface to enter the attic.

Sealing the gaps offers a second line of defense to prevent water intrusion even if your roof suffers damage during a storm. This can keep up to 95 percent of rainfall from entering your home, drastically reducing damage and repair costs.

A special tape is one option for covering up these seams. This self-adhering tape covers all joints in the roof deck, and is typically covered by an underlayment as a further protective measure. Homeowners can also choose to add only an underlayment or a waterproofing membrane.

Roof decks can be sealed from the inside as well. A polyurethane spray foam will cover up any seams in the deck visible from the attic.

Err on the side of caution when sealing the rooftop deck. American Family Insurance says even one forgotten gap can lead to significant water damage.

Sealing the roof deck is well worth it when upgrading your roof. Knockout Inspections says the materials are affordable and easily available, and roofers are familiar with the practice.

The practice is easiest and most affordable when reroofing. The Insurance Institute for Business & Home Safety says you can also add some protection without replacing the roof by taking the step of adding polyurethane spray foam from inside the attic.

When improving the roof deck, consider bolstering other parts of the roof against wind and water intrusion as well. These steps include improving flashing, adding a drip edge, and installing shingles rated for strong wind gusts.