Can You Put Metal Roof Over Shingles?

Among the questions homeowners ask is whether one can put a metal roof over shingles. In almost every case, it is possible to install a metal roof over an existing shingle roof. This is among the reasons why metal roofs keep growing in popularity.

Fitting a metal roof over a current one brings extra insulation above your home to prevent heat and cool air from escaping. Before this article comes to an end, you will learn if it’s ideal to install a metal roof over a shingle roof and what you should be aware of when doing so. 

Check out this roofing contractor in Lubbock for more information. 

Why Install Metal Roofing Over Existing Shingles?

Shingles are cheap roofing materials that require frequent maintenance and replacement. Regrettably, it is impossible to recycle shingles, and since waste disposal companies collect lots of them, they can charge high to accept the shingles.

Metal roofing comes as a solution to homeowners who want out of the shingle replacement cycle. Roofing using metal will result in a weighty up-front cost when compared to new shingles. However, these roofing materials can last for more than fifty years with minor maintenance. 

You can use a metal roof to add curb appeal to a building since they come in various styles and colors. Also, a metal roof is a product of recycled materials and is easy to recycle at the end of its lifespan.

Installing a metal roof over shingles helps the homeowner save from the costs of entirely tearing off the existing roof first. 

What To Do Before Installing A Metal Roof Over Shingles

Even before you commence the process of installing a metal roof over shingles, contact your local building authorities to ensure it’s doable in your area. Also, it is essential to address any existing roof leaks and replace rotten rafters of sheeting.

In addition, there are three methods to install metal roofs over shingles. 

  1. Running New Underlayment

The first method is running new underlayment over a prevailing shingle roof, hence wrapping the old top. The new underlayment work is to prevent water from getting under the metal roof. This is the most inexpensive and quickest way to install a metal roof.

Also, the underlayment acts as a buffer between the metal roof and the shingle roof. Over time, a metal roof without a barrier can lead to shingle granules wearing away against the back of the metal roofing panels. 

  1. Use of Battens or Purlins

The second method entails fixing a metal roof over a shingle roof with purlins or battens. Depending on the panel’s design from the metal roof manufacturer, a roofing contractor screws down the purlin to the roof deck. 

After installing the metal on the purlins, the installer gets a nice flat surface to install the metal roofing panels. Also, the method creates air gaps between the back of the metal and the shingle roof, which allows air to flow.

  1. Removing The Shingles

The other way to install a metal roof over shingles is to entirely take out the old shingles before installing the new metal roof. It enables a roofer to see any rotten plywood that needs replacement before installing the new roof.

The benefits of this method include having a chance to remove the rotten plywood to adhere to new and stricter building codes.

Steps to Take Before Fitting A Metal Roofing Over Shingles

Take the following steps to save on costs before you install your metal roofing over shingles.

  • Take note of any leaks or cracks in the roof that could lead to additional damage if not addressed before installation
  • Sweep the top and take out any debris that could pose a problem
  • Repair broken shingles that are torn or cracked
  • Remove obstacles such as air vents or pipe flashings

Advantages of Installing Metal Roof Over Shingles

There are many merits to putting your new roof over the old roof. The process is also known as re-roofing or overlaying. Some of the advantages of having a metal roof over a shingle one include the following.

  • Eco-friendly
  • An extra layer of protection
  • Reduction in wear and tear on shingles hence increasing the lifespan
  • It gives more structure durability to the roof
  • Lowered labor costs
  • Less clean up once the job is complete
  • Greater energy efficiency due to multiple roof layers
  • Short job timeline

Disadvantages of Installing Metal Roof Current Over Shingles

  • Possible low property resale value
  • Risk of unnoticed pre-existing damage beneath the shingles
  • Extra weight on the decking and supporting framework

What to Consider When Installing a Metal Roof Over Shingles

If you think about a roof overlay, here are various vital aspects you should consider.

  1. Metal Roof Design

Any metal roof can fit over shingles. However, various metal roof panels or designs perform better in the absence of shingles. Therefore, you need to deliberate on how much space you require between the metal panels and the shingles and whether the shingles will fit. Generally, make sure the design is well-matched with the current roofing.

  1. The Roofing System Weight

Most building designs support the weightiest roofing system. But, the combined weight of shingles and metal roofing may need extra support in the roofing structure. This mostly happens if the structure is old and the design doesn’t match the modern roofing materials. Also, ensure that the building can support both roofs for a long time.

  1. Manufacturer Warranty and Specifications

Various manufacturer warranties hardly cover the metal roof if you install it over shingles. Nevertheless, some manufacturers may give a guarantee but ignore coverage for any hitches connected to the shingles. Ensure you consider the warranty conditions before you buy the metal roof.

Final Words

Metal roofing is costly, but it is durable. If you want the most outstanding defense against sun, snow, rain, or wind, installing a metal roof on top of your shingles might be the best solution from a return on investment angle. The only time the setup is not ideal is when the local codes from your area prohibit fixing metal roofs over pre-existing shingle roofing.


TBN Editor

Time Business News Editor Team