You might assume that you need to look directly at a roof in order to tell whether it needs to be replaced. This could prove difficult if you are afraid or unable to climb a ladder or if your roof has a very tall peak, making it hard to see. Here's the good news: you can often tell if your roof needs replacement from the inside of your home. The following are the signs you should be looking for.
Moisture in the attic
Wait until the day of a rainstorm, and go up into your attic. Do you notice any pools or spots of moisture? These are sure signs of a leak. You should also be concerned if your attic feels overly moist, or if the insulation is moist to the touch. These signs indicate that water is coming in somewhere, even if you can't quite tell where. A leak is not always a sign that your roof needs to be replaced. Sometimes, your roofing company can just replace a few shingles and solve the problem. But if your roof is approaching the end of its life expectancy — which is 20–30 years for standard shingles — you likely need a replacement.
Spots on the wood
Take a look at the wood underlying your roof. (This wood should be exposed on the "ceiling" of your attic.) If you see any dark spots on the wood, this is a sign that the roof is leaking and probably needs to be replaced. The spots are either mold growth or the beginnings of rot. The wood may not be moist right now if it has not rained lately or if the rain has not come in at the right direction, but the spots are a sign that rain is coming in at least sometimes.
Rising interior temperatures
Has the upstairs of your home felt really warm lately? If you're sure that your air conditioner is working well and if your roof is old, this is a sign the roof has begun to give up the ghost. As shingles fall off or lose their "grit," the roof becomes less adept at reflecting sunlight, and your home gets hotter.
If you observe any of the above signs inside your home, contact a roof replacement company. They can take a close look at your roof and let you know for sure whether you need a new roof.