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Can You Roof Over Existing Shingles

The Cons Of A Roof Overlay

How Many Layers of Shingles Are Allowed on a Roof? Steep roofsð¨ and more….

Warranty Issues:

We do not give a warranty on a layover for multiple reasons. Since we are working over someone elses work we cannot ensure the installation quality of the original roof or the status of the roof deck.

Cuts the Roof Lifespan:

Due to the extreme heat that your roof endures, placing shingles over an existing roof will shorten the lifespan of the new roof. The heat of the roof and lack of ventilation will result in deterioration of the new single and a shorter life span.

Hidden Costs:

Having two layers of shingles on your roof is going to make any leak more difficult to find and more expensive to repair.

An overlay will also be more expensive in the future since sooner or later your roof will need to be replaced. When that happens, you will have to pay for tear off and disposal of two layers of shingles. That means double the labor to remove and double the price to dispose.

Difficulty In Finding Roof Leaks:

Leaks are difficult to find in general, even if it is a single shingle layer, but when there are two layers it becomes even more difficult.

Unable to Inspect the Decking:

An important part of roof tear off process is being able to inspect the decking under the shingles. To ensure a quality roof installation, we need a good, solid, nailable service to attach the shingles.

Cannot Layer Architectural Shingle:

Shingles are designed to be installed on flat services so we can not overlay on architectural shingles.

Adds Height and Weight:

Roofing Over Your Existing Roof Is Not Worth It

If you havent noticed yet, we are not fans of shingle overs not at all. We dont recommend them nor do we do them. Over the years, weve seen problems caused by shingle overs. Does it cost more to tear off? Yes. However, by spending a little more now, you can save yourself thousands in the long run.

How To Install Metal Roofing

If you choose to overlay a single layer of asphalt shingles there are quite a few things youll have to do to prep your existing roof properly.

Prepare Your Old Roof

Any portion of your existing roof that is already metal, which means valley tin, gutters, roof jacks, and chimney flashing, should come off. You can overlay the valleys and gutters, but youre asking for future problems if you do.

Cut back the shingles along the valley or gutter apron about two inches beyond the width of the metal. Pull the nails and metal off the roof. Remove all the roof jacks and any chimney flashing. You may be able to use the chimney flashing again if its not badly damaged.

Start With The Gutters

Following the manufacturers instructions, start with the new metal roof. If youre going through a layer of shingles, youll want self-taping sheet metal screws a little longer than the standard 1 5/8 screws used on new metal roof installations. The zip screws for the overlapping seams will still work fine.

Set the valleys/gutters in place with the roofing material provided in your metal roofing package. Make sure you dont screw or nail anything into the valley pan, the business end of the valleys. If water runs down it and it hits a screw, the water will find a path inside if you have an errant fastener in your valley/gutter assembly.

Lay Down The Roof In Complete Sheets

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How To Tie Into Existing Roof Shingles

Roofing work is no easy task, but some projects, such as tying into existing roof shingles is easier than it sounds. It is an easy project if you take safety precautions and install trusses that meet at the eave of your roof. Whether it be the tools for the job, working time, or costs involved, lets take a look at how you can tie into existing roof shingles.

An addition can provide extra livable space to a home and add serious extra value to a home as well. However, there are many factors to consider to ensure that the addition blends seamlessly into your existing structure. The most important thing when installing an addition is to tie the structure into your existing roof.

To tie into existing roof shingles use a cut valley. Install trusses to meet the eave of the house and nail 2 valley boards into place, securing with roofing cement. Frame and sheathe the addition roof, and snap a line on the existing shingles 2 inches above the valley. Cut through the underlayment and shingles, lay the new shingles, then re-lay the shingles you removed before.

Undoubtedly, an addition can have lasting impacts on a home in positive and measurable ways. After determining that the trusses of your home are able to stand up to the additional weight, it is time to go to work.

Metal Roofing Can Be More Cost

Steel Roofing Over Shingles

Although most metal roofing products carry warranties comparable to the very best asphalt shingles , in practice, metal roofs have been known to last 50 years or more. According to State Farm Insurance statistics, metal roofs routinely have a longevity of 40 to 70 years. It is therefore very rare for a homeowner to install more than one metal roof over the time he or she lives in the home. By contrast, a homeowner will likely replace an asphalt shingle roof two or even three or four times over a 50-year period. Overall, while the cost of a metal roof is more expensive than asphalt roofing , it can save money over a long period.

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Are There Other Materials To Put On Top Of Asphalt Shingles

If youre thinking about replacing your homes roof with something other than asphalt shingles, you could potentially leave your existing roof alone, depending on your local building code. Metal roofing materials would go well over your shingled roof! While metal could be a slightly more expensive option, there are plenty of long term benefits to consider, especially not having to tear off your existing roof. This would only be recommended if your shingles are in good standing condition because your metal will last 50 years or so while your shingles could experience buckling before your metals life has been spent.

before making a final decision. Allow them to conduct an inspection to determine the status of your current shingles and explore what financing options are available if cost is the main driving factor for shingle layering.

Ready to talk now? We are excited to discuss this topic with you! Contact us today.

Editors Note: This post was originally published in January 2019 and has been revamped and updated for accuracy and comprehensiveness in September 2020.

What Are The Advantages Of Roof Replacement Rather Than Re

When you get a roof over old roof and the old shingles are left in place:

  • Re-roofing a home is less expensive. When you get a roof over existing roof installed you are eliminating a few costly components of roof installation. The first thing youll eliminate is the cost of labor to remove the old roof. Shingle removal can be costly especially for larger homes. Not only that but youll have much less debris in the project since youre not removing the old roof.
  • Fast Installation of the New Roof. For the average size home a new roof installation can take a few days to a week. When getting a re roof on your home you may be able to get a new roof in under a single day.
  • Overall Appearance of the Roof is Good. The biggest concern that most home owners have when it comes to the re roofing project is the appearance after the roof is installed. Most re-roofs can look good but there may be noticeable differences depending on structural factors.
  • You Still Get a Warranty. Most roofing material manufacturers will provide a warranty on their products for the roof install even if the roof installation is a roof over existing roof. In order for the warranty to be honored however, the project must still be done according to local building codes and manufacturers specifications.
  • Two Roofs are Better Than One. Well maybe Some people think that an additional layer of roofing is better when severe weather strikes such as tornados, hurricanes, or blizzards.

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It’s Not Ideal To Install New Shingles Without Removing The Old Ones But Follow This Pro Advice If You Do

Although placing new roofing over old may be allowed by some codes, roofovers tend to be inferior and wont last as long as a roof installed over stripped sheathing. If you must do a roofover, check with your local building department firstcodes typically require that you strip a roof if there are two or more layers or if existing shingles are curling.

Before beginning, replace or flash over old flashing as follows:

  • Use aviation snips to cut away flashing around plumbing vents.
  • Use a cold chisel to remove chimney counterflashing.
  • Along the eaves, install a new drip-edge over the butt ends of existing shingles.
  • Along the rakes, install a new J-channel drip-edge, which wraps around the old rake flashing and starter courses.
  • Leave the old valley flashing in place, and install new over it.

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When You Should Not Put A New Roof Over An Old One

Second layer roof over – Roof leak inspection

A thorough roof inspection should precede any roof installation. The roof inspector will determine whether your roof is suitable for a re-roof or a roof replacement.

Also, you will get a roof inspection report that will have recommendations on whether your roof is suitable for a re-roof or you should consider tearing it off.

Some of the reasons why your roof might not be suitable for re-roof include

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Is The Roof Decking In Good Condition

If the roof has large leaks or long-term leaks, your decking may be in poor condition, rotting, or soft. If you arent confident your new roof will be fastened into a solid, reliable deck, remove the shingles and underlayment. Thoroughly inspect the decking and replace any areas that are in disrepair.

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Putting A Metal Roof Over Shingles

Its absolutely fine to install a metal roof over shingles. People are accustomed to thinking of metal roofs as being heavy or cumbersome. In fact, metal roofs are so beneficial because theyre very light. Theyre fast to install, and they come in large sheets rather than individual tiles.

When you install a metal roof over shingles, you actually get additional protection from the shingle roof as well as additional insulation. And having shingles under the metal roof can reduce some of the sounds that can transfer from a metal roof, though modern metal roofs have countered this problem very effectively.

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How To Install Metal Roofing Over Shingles

Homeowners looking to replace an aging roof have two basic options: they can either strip off the old roof and replace it with a new asphalt roof, or they can install metal roofing over the existing asphalt shingles.


  • 7 Conclusions
  • Unless building codes require it, there is usually no need to tear off the old roof. Installing metal roofing over shingles is the best solution.

    The metal used for the roof can be tin, copper, aluminum or steel. In terms of performance many homeowners choose a steel roof, making it the most popular option when it comes to creating a metal roof over existing shingles.

    When choosing to install a metal roof, homeowners need to take into account several trade-offs involving cost and performance.

    While metal roofs are more impervious to hail, rain and high winds, they are also more expensive on a square foot basis. But, whereas an asphalt roof may only last 20 to 30 years, a metal roof can last as long as 50 years. See our related post on how long does a metal roof last.

    If your roof is leaking , it may be worthwhile to go with the metal roof solution. It will give you decades of peace of mind. So, from a purely practical perspective, the clear winner is performance over cost.

    Can You Install A Metal Roof Over Shingles

    Can You Put Metal Roof Over Shingles

    One of the biggest questions homeowners have when they start thinking about replacing their roof is whether or not they can install the new roof over the existing one. This question especially arises when the homeowner plans on replacing a shingled roof with a metal roof. So, can you put metal panels over shingles?

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    When Can You Put A New Roof Over An Old One

    As a homeowner, you may not understand the roofing dynamics. Choosing a re-roof over a roof replacement can only be recommended by a certified roofing contractor like Roof Master. Rest assured that you will receive quality roofing services.

    Re-roofing is cheap, faster, and convenient compared to roof replacement however, it has its limitation and can only be done under given conditions

    • A re-roof is a good option if your roof is at the end of its life, but the underlying elements and the sheathing board are still in good condition.
    • If your shingles are losing granules, they are worn out due to age but are not causing leaks.
    • If your shingles are not curling or missing
    • If you want a different roof colour or design

    How Long Does A Reroof Last

    The 26 gauge and 29 gauge cheaper metal roofing options can last for up to 25 years if taken care of. On the high-end, the 24 gauge metal roofing option can last for up to 50 years. However, most manufacturers offer a 20-year warranty and some even a lifetime warranty which is dependent on the metal used.

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    Things To Know About Nailing

    Now you know what nail-over reroofing is and what the right situation for one is. But there are still some things you need to know about getting a nail-over.

    You need to be aware of the cost, warranty options, and the aesthetics that come with upgrading your shingles when you nail-over your current roof.

    Q& a: Is It Okay To Put New Shingles Right Over Old Ones

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    After the beating it took this winter, our roof needs to be replaced. Is it okay to put the new shingles right over the old ones?

    If you need to redo your roof, you might be tempted to save some money by having another layer installed over the existing shingles. But any savings you reap could cost you more later if the sheathing under the shingles is damaged and you don’t replace it now. While the building code in most towns won’t require a tear-off down to the sheathing unless your roof already has two layers, we at least a thorough sheathing inspection from beneath as well as an assessment of its condition during a walk-over evaluation. If there’s a history of leaks or insect infestation, it’s probably best to remove even a single shingle layer. This will allow your contractor to check whether rot, mold, or insects has damaged the sheathing.As for which type of shingle to use, three-dimensional, laminated-asphalt, or architectural, shingles used to cost roughly twice as much as ordinary three-tab shingles. But the Owens Corning Oakridge and CertainTeed Landmark CR Best Buys in our latest review of roofing products cost roughly the same as most three-tab shingles we tested$65 and $70, respectively, per 100 square feet, or squareyet performed better overall. Our ratings include 26 laminated and three-tab shingles , and we also covered composite and metal roofing materials.

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    So Should You Get A Roof Over Existing Roof

    When considering what type of roofing installation youll get its always best to weigh the benefits of each. While both a roof over existing roof and a tear off have their advantages, for most home owners the decision comes down to price. Depending on your budget, either of these methods can leave you with a new roof. Its always best to talk with a licensed and qualified contractor in your area. Be sure to fill in the form below to get a quote on your roofing project. You can alsovisit this link for a free quote.

    When You Can And Cannot Reroof Over Existing Shingles

    Your existing layer of roof shingles is deteriorating and you need to get a new roof installed. One question you might have is Can I reroof over existing shingles? The answer is, It depends. State regulations and the condition of your roof both play a role in determining if you need a roof replacement-tear off vs cover over.

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    Pros & Con Of Overlaying The Existing Roof #

    Overlaying your existing roof also comes with its own set of pros and cons. Whether it is the right choice for you depends on your home and the condition of your roof.


    • Affordable: Rather than ripping off your old roof and putting a new one down, you simply add a layer of shingles to your existing roof. This involves less labor, dropping your costs considerably.
    • Less time-consuming: Because there is less labor involved, an overlay job takes far less time than a tear-off job. This is ideal if you need a new roof as soon as possible, or if your budget cannot quite support the additional cost of lodging during installation.



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