Do you need a new roof? 10 ways to tell

Take it from the top
So, what should you look for when inspecting your roof? The National Roofing Contractors Association (NRCA) recommends you do a roof inspection at least two times a year -- spring and fall. The best place to begin is inside your house -- grab a flashlight and make a trip to the attic.

Here are four things to look for on the inside:

1) Places where the roof deck is sagging

2) Signs of water damage or leaking

3) Dark spots and trails

4) Outside light showing through the roof.

Exterior check
When you take a look at the exterior of the roof, pay attention to such things as damaged flashing, missing shingles, curling, blistering, buckling, rotting and algae growth (which occurs most often in humid climates and appears as dark or greenish stains).

The HomeTeam Inspection Service offers these tips on what to check on the outside:

5) Visually inspect your roof for cracked, torn, bald or missing shingles.

6) Scan the roof for loose material or wear around chimneys, vents, pipes or other penetrations.

7) Watch out for an excessive amount of shingle granules (they look like large grains of sand) in the gutters -- this is a sign of advanced wear.

8) Check for signs of moisture, rot or mold. Note that wet spots may not be directly under your faulty shingle; water can travel down to its lowest spot before it drips. Mold, fungi and bacteria can grow quickly -- within 24 to 48 hours of a water-related problem.

9) Examine the drainage, and make sure gutters and downspouts are securely attached. Also ensure all drains are open and allow water to exit, and all gutters and downspouts are free of debris.

10) Check that all bath, kitchen and dryer vents go entirely outside of your home, not just into the attic space.

What's the roof made of?
Dean Bennett, president of Dean Bennett Design and Construction, Inc. in Castle Rock, Colorado, says determining when you need a new roof also depends on roofing material as well as the part of the country in which you live. With that in mind, he offers tips on the following roofing materials:

• Cedar: A cedar roof in need of repair or replacement will split and fall apart in dry climates. In moist climates, it will get mossy. The lifespan of a cedar roof is about 20 years.
• Tile: "Look for broken or cracked tiles," Bennett says, "but don't walk on the roof to do so or the tiles will break. Tile roofs can last up to 100 years, but individual tiles can break. They can be replaced, but only by a specialist."
• Concrete: should never need replacing

If you have a roof with wooden shakes, you should also watch out for damage from termites, carpenter ants and/or other wood-boring pests.

Check the simplest solutions first
If your roof has water damage, don't jump the gun and assume you need to start all over with a brand new roof. The California Contractors State License Board says that if your roof was properly installed and is less than than 15 to 20 years old, it can often be repaired rather than replaced.

Contact a licensed roofing contractor -- or three -- to find out what they think needs to be done and to get an estimate.

Starting over
If you do decide to go ahead and replace the whole roof, keep weather and other issues specific to your locality in mind when choosing materials.

For example, wood and asphalt shingles aren't especially fire resistant -- and this could be a problem if you live near a lot of dry brush and trees. Slate, tile and metal are more expensive materials, but they are a worthwhile investment because of the extra protection they offer against fire.

If, on the other hand, snow loads are an issue where you live, you might want to consider a durable and lightweight standing-seam metal roof. These can typically cast off the snow before it becomes a problem.

But before setting your heart on slate or tile -- and we know they look really gorgeous -- realize that these are very heavy materials. Some house framing just isn't strong enough to support the extra weight of this sort of roofing.

Start now -- before you have no choice
Don't wait until water is unexpectedly pouring into your home by way of a leaky roof. Start protecting your home by using some simple observation skills. If you find problems, it doesn't necessarily mean you need to replace your roof. Many repairs can be made before a major rebuild is necessary.

If you do need a new roof, be aware that this isn't an average "do it yourself" type of project. It's tough work -- especially if you're taking off the old roof -- and can be dangerous, too. (Roofs slope and are up high... need we say more?)

It's all looking up
Most people list "Having a roof over my head" as one of life's essentials -- and there's a reason for that. It's not just a matter of practicality or aesthetics (though both of those play a part). Your roof is what keeps you and your family safe from the sun and snow, lightning and rain.

So cozy up with the knowledge that once your roof is in tip-top shape, it will stay that way for years to come.