Can You Shingle Over Shingles

Can You Shingle Over Shingles?

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James
February 22, 2022
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Are your roof shingles looking a bit damaged and need to be replaced or repaired?

You will have to decide if you’re going to remove the whole roof and install a new one or opt for reroofing instead.

What does reroofing mean?

Reroofing is when you install new shingles over your existing roof shingles.

Naturally, this can save you money on installation costs. But is it worth it?

Here’s what you need to know about installing shingles over shingles. 

What Is A Shingle Roof? 

Can You Shingle Over Shingles

Shingles are flat, rectangular pieces of composite, asphalt, or other materials. They get applied from the roof base all the way up and they are overlapped to provide coverage. Asphalt shingles are the most popular and you can find them in a variety of colors and textures.

Shingles are produced in bulk by manufacturers, which makes them cheaper to install than other types of roofing material. They also require less skill to install, therefore lowering their labor costs.

How To Install Shingles On Your Roof 

Can You Shingle Over Shingles

Before you can install roof shingles, you should lay tarp on the ground so that debris will be collected. Then you can remove the shingles, such as with the use of a shingle remover tool. Some of these tools come with the additional feature of removing nails, so you don’t have to use a hammer to do so.

Once you’ve removed the existing shingles, you can install the roof deck protection which produces a protective barrier between the external elements and your home. You will also need to install drip edges.

When laying down shingles, here are the steps to follow. 

  1. Align the drip edge so it’s flush with the roof edge, and mark a pencil line at the top of each end of the house. Using a chalk line, snap a line between the two marks so you get a straight edge. 
  2. Pull your drip edge down a half-inch from that line so that you have a gap between the fascia board and drip edge. 
  3. Nail the drip edge with galvanized roofing nails and a hammer. 
  4. Do the same steps for your gabled ends, and make sure you install a drip edge up the roof along the gable. 
  5. Place your roofing felt paper and nail it in place with galvanized roofing nails. 
  6. Begin at the bottom with laying out the shingles. Place a tape  measure half an inch away from the roof edge so that the shingles will overhang the drip edge. 
  7. Make sure you mark 12 inches up on the roof for the first round of shingles, then mark every five inches all the way up the roof so that you can set your reveal. You need to do this on both sides of the roof.
  8. With your chalk line, snap a straight line on each five-inch increment and vertically every six inches. 
  9. Cut off three tabs on a shingle, only leaving the top tar section.

What Are The Two Reroofing Methods?

Can You Shingle Over Shingles

The process of reroofing can be done in two methods. These are nesting or bridging. Here’s what to know about them.

Bridging Method 

The bridging method ensures that the new layer of roof shingles will be overlayed on two or three courses of the existing shingles. In the bridging method, you can ensure proper exposure of the shingles so it’s the go-to method when applying metric-sized roof shingles over English-sized or wood shingles.

During installation, however, telegraphing of the underlying material can occur. This is when the old layer of roof shingles is visible in the new shingle layer. 

Nesting method 

By comparison, the nesting method of reroofing shingles reduces the risk of telegraphing. It’s usually chosen as the preferred method when installing English or metric-sized roof shingles over like-sized shingles. It ensures that the application of the shingles is even and uniform.

However, this method shortens the exposure of the shingles, which will require you to use a greater quantity of roof shingles. When using this method, the top edge of the new shingle you’re laying on the roof will be attached to the bottom edge of the current shingle. 

What Are The Benefits Of Reroofing?

Placing shingles over shingles has many advantages. These include the following.

  • You can save money. The amount of money you can save will depend on the slope of your roof. Generally, though, you’ll save about 15 percent of the total cost of installing shingles.
  • You can reduce your stress. If you can reroof instead of tearing off the existing roof shingles, this can reduce the amount of time on the job by about 30 percent. This also makes it easier for roofing contractors to start installing your roof faster instead of taking time to first remove the roof. 
  • You can extend your roof’s lifespan. Reroofing instead of replacing your roof is a good option for someone who has a roof that’s getting old but is still in generally good form. So, there might be some leaks or minor water damage, but overall the roof will get a second lease on life.
  • You can prevent small issues from becoming bigger problems. If you have some loose or missing shingles but they haven’t caused larger problems, reroofing can help you to deal with the problems so that you prevent them from getting worse and causing larger damage to the roof structure. 

When Is Reroofing A Bad Idea? 

Can You Shingle Over Shingles

Although placing shingles over your existing shingles is a great way to save money and spend less time working on your roof, there are some times when it’s not a good idea to reroof your home.

  • You have two layers of shingles on your roof. It’s important to bear in mind that most building codes allow homeowners to only have two layers of roofing materials. If there are more, this violates the code. This will force you to have to remove your existing roof before installing new shingles.
  • Your existing shingles are losing their shape. When shingles curl, this means that they lose their shape, and this can happen as a result of various reasons, such as that the attic isn’t properly ventilated or your shingles weren’t installed correctly to begin with. If you install new shingles over these ones, this will prevent the roof from being flat.
  • Your roof has leaks. If your roof leaks in some places whenever it rains, you have to repair this problem. You can’t install new shingles over your existing ones because the problem will still be there and it will cause damage to your new roof.
  • Your roof feels soft. When you climb onto your roof and walk around on it, does it feel spongy or soft underfoot? This is a red flag that there’s a problem with the roof’s sheathing. Again, make sure you repair this before you go ahead and install new shingles on your roof.
  • Your roof can’t handle the weight. If your roof is old or not in good condition, a new layer of heavy roof shingles can cause it to sag. Make sure that your roof can handle the additional weight which is going to be placed on it. 

Pro tip: Before you decide to reroof instead of replace your roof, you should contact a roofing contractor to inspect your roof. He or she will walk on the roof to check its condition, such as by peeling away some shingles to check their quality and by seeing if there’s any deterioration in the roof flashing. 

Roof Replacement Vs Reroofing: What Are The Costs? 

Can You Shingle Over Shingles

If you’re not sure if you should replace your existing shingle roof or shingle over your shingles, the costs of both will play an important role in your decision.

To replace your roof, you can expect to pay between $2,500 to $6,500 if you decide to do it yourself. When you call the pros to install a new shingle roof, you can expect to pay between $8,700 to $22,000 on average.

This is because labor costs are a big part of the expense. Bear in mind that removal of your existing roof can cost between $,1000 and $1,500. 

If you’re going the DIY route, there are important things to bear in mind when installing a new shingle roof. These include the following:

  • Removing your existing shingles can be a difficult job if you don’t know what you’re doing or you’ve never done this work before. 
  • You have to be comfortable with climbing the roof as you risk injury when replacing your roof yourself. 
  • While this DIY project involves removing the existing shingles and putting in new ones, you also have to insulate the roof and set up your gutters. 
  • You might need to get a permit before you can replace your roof. 
  • By not using the services of a roofing contractor, you miss out on getting a roof warranty. 

The cost of replacing your shingle roof will also depend on the type of shingles you want for your roof

Asphalt 3 tab shingles cost $1.00 per square feet and installation costs are between $5,000 and $12,500. By comparison, asphalt architectural shingles cost around $1.50 per square foot and installation will cost between $12,450 and $15,785. 

What about reroofing? If you want to install shingles over shingles, which is called overlaying in the construction industry, it will save you around $1,000 or more because you won’t have tearoff and labor costs. 

How Long Can You Keep Reroofing A Roof? 

Can You Shingle Over Shingles

Seeing as though building codes sometimes specify that you shouldn’t have more than two layers of shingles on your roof, this is a rule worth following. However, building code aside, it does depend on the type of roof you have.

Even if your roof is in good condition, you shouldn’t have more than two or three layers of shingles on your roof as this will make it too heavy. It can also start to compromise the roof’s condition, forcing you to have to remove your current roof and install a new one. 

How long does an asphalt roof last? 

An asphalt roof usually has a lifespan of around 20 to 40 years. 

What are the benefits of asphalt shingles?

Asphalt shingles are strong and durable, while being cost-effective and suitable for a variety of roof styles. They’re also relatively easy to replace.

How long will a reroof last?

As long as the reroofing is done correctly and your roof was in good condition to be able to handle the second layer of shingles, it can last for as long as a new roof.  

Conclusion

If you want to save some money on roofing material installation, you might consider installing shingles over your current shingles. Is this a good idea?

In this guide, we’ve featured all the information you need to know about putting shingles over shingles, such as its benefits, drawbacks, and when to avoid it to ensure your roof is strong and durable.

As long as your roof is still in good condition, laying down a second layer of shingles instead of tearing away your existing shingles can be a cost-effective way to get a roof makeover.

Reference Articles:

James

James Weldon is a professional roofing contractor with many years of experience on the job. He does not only handle large projects and provide excellent services for his company’s many clients; James Weldon also dedicates his spare time to teaching others useful tricks of the trade. Using BuildCampus as an avenue to reach many roofers and aspiring roofing contractors, James Weldon continues to provide high-quality educational posts and buying recommendations for anyone who visits the website.