A roof is a major investment, so it’s smart to do whatever’s necessary to make sure it stays in good shape.
 
Regular Maintenance
Regular inspection and preventive maintenance will keep small problems from becoming big ones. It’s smart to hire a roofing professional to check things out on a regular basis, and do all the necessary maintenance.
 
If you decide to climb up there and check the roof yourself, there are a number of problems to look out for:

• Standing Water – When water is ponding on a roof, it means there is improper drainage, and water can begin to damage structures. It may be necessary to install roof drains, or clear obstructed drains that are already in place.
• “Alligatoring” and Blistering – When cracks appear in the surface of a built-up roof, cold weather can create channels that hold water.  

Ventilation
The free flow of air around and under a roof is critical to its durability. Without it, heat and moisture build up and can cause shingles to buckle and rafters to rot. Never block off your roof’s louvers, ridge vents, or soffit vents, even in the winter. Attic ventilation prevents structural damage, increases the life of your roofing material, and increases the comfort level of the rooms beneath the attic.

Use these links to educate yourself:

NRCA’s Information for Homeowners
http://www.nrca.net/consumer/homeowners.aspx
 
NRCA’s Information for Building Owners
http://www.nrca.net/consumer/checkup.aspx
 
Tile Roofing Institute’s FAQ on Tile Roofs
http://www.tileroofing.org/tri.aspx?id=180
 
Tile Roofing Institute’s FAQ on Hurricane Damage
http://www.tileroofing.org/tri.aspx?id=180