You are currently viewing Is It Possible To Do a Metal Roof Replacement Over Existing Shingles?

Is It Possible To Do a Metal Roof Replacement Over Existing Shingles?

Due to their lower costs and long-lasting durability, metal roof replacement is highly popular. The question that many homeowners are asking is this: can a metal roof get installed over existing asphalt shingles?

It Is Possible And Here’s Why!

It is very much possible to install metal roofing over asphalt shingles due to their light weight and high durability factor. Asphalt shingles can weigh four pounds or more per square foot while metal roofing only weighs about a pound. This means installing it over an existing roof wouldn’t significantly burden the load of the roof itself, and as such, the shingles can remain.

Is It Worth Installing This Way?

The answer depends on a variety of factors as with anything else in life. Metal roofing materials are great insulators and they don’t need a hefty upfront investment unlike their shingled counterparts. Metal roofs can also reflect heat back and make it easier to control indoor temperatures. Ultimately, this protects the roof from trapping heat underneath.

Before investing in a metal roof, there are a few things to take into consideration:

  • Does your current roof exhibit leaks or have rotted spots? If so, these need to be addressed before a metal roof can get installed.
  • Are metal roofs over shingles allowed in your zoning laws? Some areas prohibit roofing installations in this way, so it’s worth checking.
  • Are there structural problems caused by the weight of your current roof? If you notice signs of sagging, dipping or buckling, these need repair before a metal roof can go up.

The granules that exist on the asphalt shingles can corrode the metal over time if a buffer material is not installed between the two components.

Advantages Of Choosing A Metal Roof

  • Unlike asphalt shingles, metal roofing can last up to five decades with limited care.
  • Metal roofing has the ability to withstand inclement weather patterns ranging from ice storms to heavy gale-force winds.
  • Another great aspect of metal roofing is that it requires very little in the way of maintenance or repair throughout the years.
  • Metal roofs have a special coating that eliminates the trapping of heat. This means that during the summer months, there’s less reliance on AC units.

2 Ways To Install A Metal Roof Over Shingles

Metal Roof Replacement ContractorsThere are two methods that are employed in order to install a metal roof over existing shingles. The first one is to apply an underlayment that will ensure no leaks or water damage occurs underneath the metal roof. Many asphalt roofing materials are prone to leaks over time, so this kind of additional protection is highly recommended by roofing professionals. This underlayment also offers an adequate barrier against corrosion from the asphalt granules and will prolong the life of the metal.

The second option is for the contractor to use purlins or battens. This involves directly screwing purlins into the existing roof deck depending on the existing construction’s layout. The metal roof is then laid over the purlin. This option offers a smoother finish as the contractor doesn’t use the metal to accommodate grooves and curves in the existing shingles.

Are you ready to invest in a new roof? If so, a trusted local contractor can help you go over the options available at your disposal. Armadillo Roofing & Exteriors (512) 333-7663 provides commercial metal roof restoration, commercial metal roof repair and commercial metal roof installation services to Austin, Texas and the surrounding Austin area communities. You can also reach us at

A metal roof may not always offer the best investment choice for property owners, but as a commercial roofing company, we can help by educating you. After assessing your needs and the state of your existing roof, we can discuss the next step for installation.

Leave a Reply