The answer is yes, you can lay new roof shingles over old ones. Now that we’ve taken care of the primary question at hand, we’ll consider a couple of reasons why you might want to do this. Then we’ll look a lot more reasons why you might not want to do this. But before we get started, one thing must be clear: adding new roofing over old (sometimes called a “re-roof”) is possible only with asphalt shingles (also called “composition shingles”). You can’t do it with wood or slate, for example, and you should never mix materials, such as laying asphalt shingles over cedar shakes. Also, the old roofing has to be in pretty good condition. Otherwise you’re just putting lipstick on a pig.

Naturally, there are a few factors that can lengthen or shorten the life of your roof, but in general, an asphalt roof can be expected to last about 20 years, while a metal roof will last a conservative 50 years. That said, things like climate, extreme weather, and maintenance can affect the lifespan of your roof. If you live in an area that regularly gets heavy snowfall or high winds, your roof might take a bit more wear and tear than is standard. Alternatively, roofs that are regularly inspected, maintained, and washed can be expected to last a bit longer.

It’s good to know that in most cases, your roof is protected from major unexpected damage, like vandalism or fire, by your homeowner’s insurance policy. In terms of minor issues, like cracking or curling shingles, most roofs come with a warranty. Typically, a roofer’s warranty for the labor on your roof is at least 10 years.

Every roofer provides different warranties, and different roofing materials come with different manufacturer warranties protecting from damage. It’s a good idea to take a few bids from multiple roofers and materials to see what warranties they’re offering, and which is best for you.

One or two leaks are not a major disaster. So long as you call a roofing professional and get the leaks fixed as soon as you notice the problem, your roof will probably be fine. If you have more than one or two leaks, however, you may be looking at some more extensive repairs.

Additionally, if you wait to get leaks fixed, water can seep under shingles and begin to rot away at the roof deck. When this happens, there’s typically no other solution than to get your roof replaced. It’s important to make sure you call a professional at the first sign of a leak if you’re looking to avoid a total roof replacement.

If your roof is older or has seen a bit of damage, it’s good to know that you do have options when it comes to re-roofing. So long as your home has only ever had one roof, you have the option to simply install another roof over the existing one. This saves you a lot of money and time, but it can only be done if your older roof was in decent shape.

When you install a new roof over an existing roof, you can opt for another asphalt shingle roof, of you can go with a lighter metal roof. Both have their benefits, but a metal roof will put less weight on the structure of your home and is likely to last longer. When you’re considering re-roofing, it’s a good idea to chat with an experienced roofing professional to see what the best option is for your home, and your budget.