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Commercial Metal Roof Repair: What You Need to Know

May , 2023 | 14 min. read

By Joe Martinez

strip mall with metal roofing

If you have a commercial metal roof leaking or if you are not sure if you need to have an older commercial metal roof completely replaced or repaired, you have come to the right place. Just finding someone knowledgeable in commercial metal roof repairs can be a difficult task, let alone actually doing the work!

From what we can see, finding someone knowledgeable and trustworthy here on the internet is a rare occurrence. Almost like chasing that infamous pot of gold at the end of a rainbow when we were kids. Except for today, there is going to be a pot of knowledge and value in place of the gold.

If you are like me, when you go searching for something specific here on the internet and you can't find it or even worse you get promised to have your question answered only to find out after reading an 12 min article it was a bunch of fluffy b.s. that never answered said question. 

Frustrating, right?

Well, today we've decided to share our 30 years of experience working on commercial metal roofs with you. We promise you by the end of this article,  you will understand the 7 common metal materials used on commercial buildings, the level of difficulty, or let's say what is required for an experienced metal repair contractor to perform a successful metal repair and we'll also cover the 3 most common installation errors we see on commercial metal roofs.

Let’s dive right in!

7 Common Types of Commercial Metal Roofing


The type of metal roofing and the overall condition of the metal roofing on your commercial property will be one of the main factors that go into determining if the metal roof can be repaired or should be replaced. 

long commercial trapezoid metal roof on a commercial building

After performing a thorough commercial roof inspection, a skilled metal roof repair contractor will be able to provide you with the answers.

Because all of the different metal options have unique qualities, they are typically chosen depending on the overall performance needs that are required for a specific geographical area and the overall lifespan desired. Some metal roofing lasts much longer in certain climates or geographical areas.

Repairing them also requires extensive metal roofing knowledge and different skill sets depending on which metal type is on your commercial building. Therefore, commercial roof repair costs will vary depending on the different factors.

Let’s go over the different metal materials first and then I will discuss some repair options.

Common Types of Metal Used For Commercial Roofing And The Average Cost For Each 


  1.  Copper metal roof - average cost is 22.33 to 31.18 per square foot.
  2.  Lead metal roof - average cost is 19.78 to 28.51 per square foot
  3.  Zinc metal roof - average cost is 18.63 to 26.97 per square foot
  4.  Terne metal roof - average cost is 17.25 to 24.43 per square foot
  5.  Aluminum metal roof - average cost is 13.92 to 19.77 per square foot
  6.  Steal metal roof - average cost is 9.52 to 18.90 per square foot
  7.  Galvalume metal roof - average cost is 8.22 to 17.89 per square foot

Copper Metal Roofs 



Copper is one of the true lifetime metal roofing material options available today. Being one of the rarest of the metal materials used for commercial roofing combined with its non-corrosive or rust-free qualities, this also makes it one of the more costly metal materials used for commercial properties.

Copper has often been used in government buildings, financial institutions, and places of worship. The oldest copper roof on record was installed on the Christ Church in 1727.  Copper Adds Elegance to North American Historic Landmarks. 

Because of its workability and the beauty from the copper aging or turning patina, paired with its longevity, copper has been one of the most prestigious metal roofs of our time.

Repairing copper takes extreme craftsmanship and extensive metal knowledge. Seams and joints on copper are soldered. Once the copper patinas, the copper has to be cleaned back to its original form in order to receive the solder. This can be a very delicate and difficult task but for a skilled metal expert, it is achievable.

Lead Metal Roofing


Lead roofing

Lead roofing is another one of the top materials used on special and unique roofing projects. Most lead roofs have either a copper or zinc base with a lead-coated finish. This helps to cut down on the overall weight without losing its insulating features.

Lead can be molded to shape and fit special roof designs. It is most commonly used on low slopes or flat roof areas. It provides a weathered silver finish and withstands all the  UV rays from the sun and is a non-corrosive material. Because of this, lead is one of the longest-lasting metal materials available for roofing projects.

Lead is used on commercial buildings and performs extremely well around harsh saltwater weather conditions. If you live on or near the saltwater then you know just how harsh the saltwater can be, it destroys most materials in little to no time at all. 

Repairing this roof is somewhat similar to the copper roof in that its seams and joints get soldered. However lead is a little easier to clean, nonetheless, it still requires a skilled metal roof repair expert to tackle the task.

Zinc Standing Seam Metal Roofing


standing seam metal roof with valleys

Zinc metal roofing is commonly used in standing seam metal roof installations. It is more popular in the European market but has become a very popular roof system here in the United States. Rheinzink, based in Germany is the world’s leading producer of zinc roofing materials. 

It is a non-corrosive material, it won’t rust, and it is also fire-resistant and fungus-proof. Zinc is also a very flexible material that makes it easy to form and flash very difficult areas on your commercial building.

With the proper installation and underlayment, a zinc roof system will last up to 100 years. When it patinas it turns to a beautiful natural silver-gray color.

Repairing a zinc roof is much like the copper and lead where the seams and joints typically need to be soldered. Cleaning and preparing the zinc roof for repair is the most critical part of the job. Again hiring a skilled commercial metal roof repair company is imperative to salvaging the roof system and making a successful repair, instead of replacing the entire roof.

Terne Metal or “Tin Roofing”


Terne metal is commonly referred to as tin roofing. Terne is actually an old English word for tin or “the metal.” A tin roof has a steel base or core coated with a tin alloy finish. This roof is not as popular as the previously mentioned metal because it does require maintenance. Once the tin alloy coating wears off it will need to be coated to protect the steel from the weather elements or it will rust. 


If the roof has been properly maintained over the course of its life, repairing the roof can be done with less difficulty. The existing condition of the metal plays the biggest role in whether the roof can or even should be repaired.  

Without having been properly maintained I have seen many of these commercial metal roofs past the point of being able to perform a successful repair. This typically shows up by the metal being completely rusted out in large sections in multiple areas on the roof.

Having been somewhat maintained over the course of the years, repairing can mean doing some extensive prep work and applying a high-quality metal roof coating to protect the terne metal from the elements. This will typically get you another 5 to 10 years depending on weather conditions and of course the overall condition of the terne metal itself prior to making the repair.

Now that you know about specialty metal roofing, the expensive stuff! Let's talk about the more commonly used metal roofing. We like to say, the stuff we regular and common people can afford.

3 Metal Roof Materials Most Commonly Installed on Commercial Buildings


The 3 metal roof materials that are most widely used on both residential homes and commercial properties in the US over the past 30+ years are:

Aluminum standing seam from a birds eye view

  • Aluminum
  • Steel
  • Galvalume

Well, the 3 metal materials are the most economical, so they are all more cost-effective than the previously mentioned rare metal materials. They also provide a wide range of aesthetic looks, longevity, and price ranges.

The 3 of these metal roofing materials, aluminum, steel, and galvalume come in the form of a standing seam metal,  2 or 3-foot wide metal panels, or a shingle-style metal profile.

Aluminum Metal Roofing


Aluminum is one of the most natural energy-efficient metal roof materials around. It is highly reflective, fire-resistant, and non-corrosive. So, if your building is on or near the ocean or saltwater this is a great choice of metal material because it will not rust.

before and after pictures of a hotel with old Spanish tile and new aluminum standing seam metal

Aluminum metal comes in different thicknesses and typically for roofing we use a 032, 040, or 050 thickness. The higher the number the thicker the aluminum will be. 032 and 040 are the most widely used on roofs. Aluminum also comes in a mill finish or a painted finish.

Mill finish will provide you with a raw metal look and it will oxidize into a naturally beautiful raw metal finish. Aluminum also comes in a wide variety of painted finished colors. Most of the paint finishes come with a 40-year paint warranty with some manufacturers offering a 45-year paint finish warranty.

Standing seam metal roofs require a very high skill set to get a properly installed roof system that will last you 75+ years if the workmanship is done right. Because aluminum is a softer material it makes it a little easier for the installer to fabricate the flashings and custom metalwork needed to get a great finished roof.

Repairing a commercial aluminum metal roof requires a metal roof expert, someone with extensive knowledge and experience working with metal flashings. However, the prep work and labor required are not as bad as the rare metal materials

Steel Metal Roof 


Steel roofing is by far the most popular metal roofing material used for commercial and industrial buildings. Steel metal is galvanized steel that is hot dipped or coated in a zinc coating. Steel is less costly and can be as effective and efficient as the other metal materials that are available. 

The steel most commonly used for roofing comes in 24 gauge, 26 gauge, and 29 gauge. Don't get fooled, unlike aluminum, the lower the number the thicker the steel metal roofing will be. 

4 of the most common steel roofing profile that is used on homes or businesses:

simple 5v roof

  • Standing seam metal panels (12”-18” wide panels)
  • Interlocking steel shingles  (slate or shake look)
  • 5-V crimp metal roofing (2-foot wide panels)
  • PBR-Panel, Maxi-rib, or multi-rib panels (3-foot wide panels)

Because steel is not a non-corrosive metal, these metal roofing materials require a painted finish. Paint finish warranties range from 20 years to 45 years depending on the thickness, type of panel, and the manufacturer of the materials.

Repairing steel metal roofing is identical to aluminum with the exception of the exposed fastener roofs. Aluminum doesn't typically come in exposed fastener profiles. Repairing exposed fasteners is definitely much easier on a commercial metal roof repair technician. 

Galvalume Metal Roof


Galvalume metal is also a metal material that has a steel core and is coated with an aluminum coating to prevent corrosion. Galvalume is much like steel roofing and comes in the same thicknesses, 24 gauge, 26 gauge, or 29 gauge. 

Commercial multi-family building with a galvalume screw-down metal roof

It is also available in all 4 of the different panel profiles. The main difference with galvalume is that it comes as a mill-finish metal product, so it does not have a painted finish. This makes it slightly less expensive and easier to work with as the painted materials can get scratched during installation if not handled carefully. It is also a great option to use around the ocean or if you live anywhere near saltwater. 

Making repairs to galvalume are identical to steel, the only difference again is that the galvalume does not have a painted finish so your metal repair contractor will not be required to match a specific color when repairing your metal flashings, such as eave drip, valleys, ridge caps and roof to wall flashings. 

So now that you know the different types of metal, and that depending on the overall condition of the metal material themselves, in most cases, we are capable of making commercial metal roof repairs but we definitely will need to do a commercial roof inspection to determine the right course of action for your building.  

3 Common Installation Mistakes On Commercial Metal Roofs


There are 3 common installation errors we find regularly on commercial metal roofs, including:

cracked flashing

  1. Improper installation of the roof-to-wall flashings
  2. Improper installation of metal roof components (valleys, pipes, hip, and ridge caps)
  3. Improper installation of metal roof fasteners

All 3 of these things typically are the result of inexperienced installation, meaning shingle crews or shingle installers who are unskilled and untrained in metal roofing making an attempt to install a metal roof. system. 

Unfortunately, we’ve seen this happen pretty frequently in the commercial roofing industry over the past decade. The good news is that in most cases these metal roofs can be repaired, depending on what has caused or is causing your commercial metal roof to leak. We usually find that the metal itself is in pretty good condition. 

Now, it does require removing and reworking the metal roofing parts that have not been installed properly. The improper use of fasteners can be repaired if it is an exposed fastener screw-down metal roof system. Here are the problems we see with the improper fastening of a metal roof:

  • Overdriven screws
  • Under driven screws
  • Screws installed at an angle
  • The use of the wrong type of screw altogether

If your metal roof was installed with hidden clips or a concealed fastener, repairing your metal roof may not be an option. A hidden metal fastener means all the fasteners are under the metal roofing and can not be seen. If the commercial metal roof installer used the wrong type of fasteners, the entire metal roofing system will most likely need to come off and be replaced.

Concealed Fastener being installed on standing seam metal roof


Metal roofs are rated to withstand some of the highest wind storms. Commercial metal roofs that blow off in lighter wind storms have typically been installed using the wrong type of fasteners or an insufficient amount of fasteners. 

Repairing an Older Leaking Commercial Metal Roof


Having an older commercial metal roof does not always mean that it has to be replaced if it develops a leak. Metal roofs installed properly can last an extremely long time, 50 years or more. It may just need some experienced TLC. 

up close photo of a red standing seam roof with a chimney and 2 sun-tunnel skylights

So, if your roof is older, don’t panic!

A lot of times we see leaks happening on older commercial metal roofs at the penetrations (chimneys, skylights, dormers) or pipe vent flashings. All of these components require a special sealant to work with the metal and as you may guess, the sealant needs regular maintenance.

The metal expands and contracts with the temperature changes. This thermal movement over long periods can cause these components with the sealant to fail. In most cases, these can be repaired by being reworked. 

If you have an older metal roof, we recommend having your local commercial roofing contractor come out and do a thorough inspection of your roof. Any reputable metal roofing contractor will make sure the metal has useful life before they provide you with a solution to repair your leak. 

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Which Commercial Metal Roof is Right For You?


Is one better than the other? When deciding which metal roofing material to choose for your commercial building consider these factors:

As you can see, there are several factors and variables that go into determining if your commercial metal roof can be repaired. 

Here at RoofCrafters we have been sharing our metal roof knowledge and performing commercial metal roof repairs for our many clients in South Carolina, Georgia, and Florida for 30 years and counting. So, as you probably can imagine, we have inspected and repaired some of the worst cases of commercial metal roofs needing repairs.

If you would like one of our professional commercial roofing estimators to come out and perform a thorough roof inspection on your commercial metal roof, click the schedule an inspection button below and we look forward to helping you soon.

Schedule an Inspection

Joe Martinez

At RoofCrafters, our mission is to provide job opportunities for others to thrive and grow while making a meaningful impact within our communities.