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Roofing Over an Existing Roof

roofing over an existing roof

So it’s time for a new roof. If you’re like a lot of people, you might be wondering if there’s a way to avoid a full roof replacement.

Believe it or not, there is. Some homeowners choose to get a new roof installed directly on top of the old one. It’s quicker and less expensive, but should you do it? The truth is, you’ll always get better quality with a full replacement, but there are pros and cons to both options.

First, let’s look at how roofing over, also called recovering, an existing roof actually works.

How Does It Work?

With a traditional roof replacement, we completely tear off your old roof and install a shiny new one in its place. When you recover, your old roof stays, and the new roof gets installed on top.

Sounds simple enough, right? Unfortunately, it’s not an option for everyone.

Roofing Over Your Existing Roof Is Not Always Possible

There are a few situations where roofing over an existing roof just isn’t possible. The only way to know for sure whether it will work for you is to ask a professional roofer. We’re happy to give you a free inspection.

For now, here are the most common reasons it might not be an option:

  • moss on roof shinglesYou don’t have asphalt shingles. You can’t roof over wood or slate tiles. And you can only install shingles over shingles — in other words, you can’t mix materials.
  • You already have two layers of roof. You never want to add a third layer of asphalt. If your roof gets too heavy, it’s more likely to get damaged in the future.
  • Your old shingles are curling. Old shingles can curl over time. You need a flat surface to install a new roof over existing shingles.
  • There’s a lot of visible damage. Mold, rot, or other significant damage needs to be taken care of with a full replacement, not hidden by new materials.

Once you know whether or not roofing over your existing roof is an option, you’ll need to decide whether it’s actually the best option for you.

Let’s look at some pros and cons.

Roofing Over Your Existing Roof: Pros

There are two reasons people generally choose to recover their current roof instead of getting a full replacement: cost and time.

It saves money. Roofing over your old roof can save you around $1,000 on installation costs, because the roofing company won’t have to remove and dispose of old shingles. It can save you money at the time, but it might actually end up costing you more in the long run. I’ll explain why later.

It saves time. It’s faster for the same reason it’s cheaper. You skip the process of removing the old roof and get straight to installation, making the whole process quicker.

roofers roof relplacement

Photo: David Mulder

Sounds great, doesn’t it? So why wouldn’t someone want to go for the quicker, cheaper option?

Roofing Over Your Existing Roof: Cons

There are several downsides to recovering an existing roof. Most of them have to do with the fact that, what you’d be saving in time and money right now, you’ll have to pay for somewhere down the road.

Let’s look at the main disadvantages:

Problems can go unnoticed. Is there a chance your old roof has leaks, mold, algae, or rot? Check out these 7 warning signs. But even if you can’t see it, the damage might still be there. In that case, the last thing you want to do is cover it with a new roof. Then, problems will likely continue to get worse. Plus you’ll eventually have to go through the new roof layer to fix it.

You’re adding weight on your roof. Your house will suddenly have to hold up twice as much weight. That puts stress on the underlying structure of your roof.

More shingles = more heat. Too much heat can damage roof shingles. When that happens, they start to look curled and misshapen. Your roof will trap less heat if it only has one layer.

Your next roof replacement will be even more expensive. When the house eventually needs a full roof replacement, it will cost more. We can’t add a third layer of shingles, so we’d have to rip out the two old layers. And we’d need to address damage to the bottom layer that might have gone unnoticed before.

A layer of old deteriorating shingles can make your new roof look bad. If your existing roof is fairly old, there’s a good chance the shingles are damaged. Shingles that are raised or misshapen make it hard to lay a smooth, flat layer of new shingles on top.

Your house will probably be worth less. Unfortunately, the money you save by avoiding a full roof replacement comes out of the value of your house. A house with a brand new single layer of shingles is worth a lot more than one with old materials (and possible damage) underneath.

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So should you roof over your existing roof? We always recommend a full replacement, but it’s up to you.

My goal is to give you as much information as I can so you can make the best decision for your house. Roofing over an existing roof isn’t necessarily the wrong choice. If your current roof is in good condition, or you’re really short on time, it might be your best option.

On the other hand, a full replacement not only leaves you with a better-looking, higher-quality roof, it also protects the value of your home and could save you money in the long run.

Still not sure which option is best for you?

We’ll give you a free inspection and roof replacement estimate with no obligation to buy anything. We know money is a real issue for a lot of homeowners, so we can also help with financing too.

Give us a call at (503) 537-0158!