"How is the roof" is a very common question from home buyers. No wonder, as it can be costly to replace depending on the problem. A quick look from the outside is one way to tell the condition of the roof, but there could be problems below the shingles as well, which is why a qualified, reliable home inspector is always recommended during a home purchase.
Did you know some asphalt shingles will need to be replaced every 10-20 years, despite manufacturer guarantees that promise 20 or 30 years or even 50 years. It's important to understand that there is a catch to the guarantees. Read about the catch with ashpalt shingle guarantees from Mike Holmes here.
If you need a new roof, there are many choices and you can read what Mike Holmes has to say about each here.