Metal Roof Restoration: The 3 Best Ways to Do It
June 29th, 2023 | 8 min. read
Replacing a metal roof is expensive.
If you're running a business under that roof, it can also be disruptive, shutting down operations temporarily or - at the very least - inconveniencing your business.
Fortunately, you may be able to avoid both the expense and the disruption by restoring rather than replacing your roof.
With over 20 years of experience in the industry, at GIDEON, we've replaced and restored millions of dollars worth of metal roofs, from barns to huge industrial plants. Our team deeply understands restoration methods and has the know-how to advise building owners and facilities managers like you.
In this article, we'll delve into 3 metal roof restoration methods: Retrofitting, Elastomeric Roof Coatings, and Spray Foam Roofing. For each, we'll explore what it is, how it's installed, the costs involved, and its respective advantages and disadvantages. After reading this article, you'll be well-prepared to make a decision that best suits your needs, budget, and long-term property goals.
So let's venture into the world of metal roof restoration together, one method at a time.
Table of Contents
Retrofitting
What is Retrofitting?
Retrofitting is a method of roof restoration wherein a new roof is installed on top of an existing one. In terms of metal roofs, this often involves adding a layer of either metal roofing or a single-ply system over the old roof, providing a rejuvenated surface and structure without the need to remove the underlying one. Retrofitting is often employed when the old roof is still structurally sound but has aged.
Installation of Retrofitting
Retrofitting a metal roof begins with an assessment of the current roof's structure and condition. After determining that the existing roof is strong enough to support a new layer, the roofing contractor will attach a framework to the current roof. This framework serves as a supportive structure for the new metal roof. The new metal panels are then fastened to this framework, effectively creating a new roof over the old one. The retrofitting process also includes sealing the seams and edges of the new roof to prevent water ingress.
Cost of Retrofitting
The cost of retrofitting can vary widely based on the size of the roof, the type of new metal used, and labor costs. On average, retrofitting a metal roof can range from $6 to $18 per square foot, depending on how large or complex the roof is, making it a moderately-priced option for roof restoration.
Advantages of Retrofitting
Retrofitting offers several benefits.
- Extends a roof's lifespan by adding a new, durable layer that resists weathering and damage.
- Reduces waste, as the old roof remains in place rather than being sent to a landfill.
- Can improve a building's thermal efficiency, as the new roof can be installed with added insulation.
- Less disruptive than a full roof replacement, as it doesn't expose the building's interior to the elements during installation.
Disadvantages of Retrofitting
Despite its benefits, retrofitting also has some drawbacks.
- Adds weight to the structure, which may be an issue for some buildings.
- While retrofitting can seal minor leaks, it may not be the best solution for roofs with extensive water damage or structural issues, as it may cover up these problems without resolving them.
- Although a retrofit is less disruptive than a tear-off, it can be as expensive or more than a full replacement.
Elastomeric Roof Coatings
What are Elastomeric Roof Coatings?
Elastomeric roof coatings are fluid-applied coatings that dry or "cure" to form a tough, seamless, waterproof membrane over the surface of the roof. They are designed to protect and prolong the life of any roof, including metal roofs. The term "elastomeric" refers to the elastic properties of these coatings, which allow them to expand and contract with the roof during temperature changes, thus preventing cracks and leaks.
Installation of Elastomeric Roof Coatings
Applying an elastomeric roof coating involves making any necessary repairs to the existing substrate, cleaning it, and then applying the coating with rollers, brushes, or spray equipment. The roof must be completely dry and free of debris before application. Usually, at least two coats are applied to ensure a consistent, leak-proof membrane. The coating must then be allowed to cure for a specified period.
Cost of Elastomeric Roof Coatings
Elastomeric roof coatings can range from $3 to $7 per square foot, making it one of the most cost-effective methods for restoring a metal roof. This price includes both the material cost and the application labor.
Advantages of Elastomeric Roof Coatings
- Significantly extend the life of a roof by protecting it from UV rays, harsh weather conditions, and hail damage.
- Completely seamless, so it's excellent for preventing leaks.
- Help you save on your energy bill
- Cost less than retrofits and new roofs.
- Easily maintained with a cheap maintenance re-coat every 10-15 years.
Disadvantages of Elastomeric Roof Coatings
While elastomeric roof coatings have many benefits, they also have some downsides.
- Overspray - If coatings are sprayed onto the roof, wind may blow some of it off the roof and onto plants, vehicles, or people on the ground. There are measures that you can take to mitigate or prevent this.
- Can't be applied in certain weather conditions - they can freeze during application if the temperature is below 50 degrees Fahrenheit.
- Requires a very competent installer. You are, in a sense, manufacturing the roof membrane on-site. This requires an experienced installer who understands the chemistries of the coatings.
Spray Foam Roofing
What is Spray Foam Roofing?
Spray polyurethane foam (SPF) roofing is both an extremely powerful insulation material and a tough, durable roofing system. It's sprayed as a liquid onto the roof, where it expands into a foam, creating a rigid layer of insulation that is tough enough to walk on (yes, it will handle your cowboy boots) yet flexible enough to withstand most natural movement of the building structure.
An elastomeric coating is sprayed on top of the spray polyurethane foam (SPF) layer to protect it from UV rays (without the elastomeric coating, the foam will gradually burn off in the sun). Like elastomeric coatings, SPF roofing is particularly suitable for roofs with unusual shapes or penetrations (including both exposed fastener roofs and trapezoidal standing seam metal roofs) as it seamlessly adheres to the existing roof, eliminating potential leak spots. The advantage of SPF over coatings, however, is that it is a powerful insulator - so powerful, in fact, that it can dramatically reduce your heating and cooling costs.
Installation of Spray Foam Roofing
SPF roofing begins with a thorough preparation of the existing roof, which includes a thorough cleaning and the repair of any existing cracks or leaks. Then, the SPF mixture is sprayed directly onto the roof, where it expands and cures, forming a seamless monolithic insulation barrier. The elastomeric coating is then applied over the foam to shield it from harmful UV rays and weather.
Cost of Spray Foam Roofing
The cost of SPF roofing can range from $5 to $9 per square foot, depending on the thickness of the foam and coating. This makes it more expensive than elastomeric coatings but still reasonably affordable compared to total roof replacement.
Advantages of Spray Foam Roofing
Spray foam roofing has several advantages.
- Provides the best insulation of any product on the market, dramatically reducing energy costs.
- Its seamless nature eliminates leaks.
- Reduces expansion and contraction of the underlying metal panels.
- Lightweight, which puts less strain on the building structure while still providing a tremendous amount of shear strength.
- Can be maintained indefinitely, as it is always covered with an elastomeric coating that can be continuously renewed.
Disadvantages of Spray Foam Roofing
SPF's disadvantages are similar to elastomeric roof coatings:
- It must be installed under specific weather conditions, as it's sensitive to moisture and temperature during application.
- Installation also requires a high level of expertise and specialized equipment.
- Over time, the top layer of the foam can degrade if exposed to constant sunlight and should be re-coated every 10-15 years.
The Upshot
Choosing the right method to restore your metal roof, understanding the process, and calculating costs can be overwhelming. The potential risks of premature failure, leaks, and reduced energy efficiency add to the stress. This is especially true given the diverse range of solutions available, each with advantages and disadvantages.
We hope this comprehensive guide from GIDEON has illuminated the path for you.
Now that you're equipped with this knowledge, it's time for you to take the next step. Remember, our team at GIDEON is always ready to assist you in this process. Reach out to us for a consultation - in a free 30-minute consultation, our roofing experts can provide you with customized guidance. Your roof is an investment, and we're here to ensure it continues to deliver value for years to come.
Schedule a Free Call
Hop on a call with a GIDEON expert and learn more about how GIDEON can help you with your commercial roofing project.
Eric Schlossenberg started roofing when he was 24 years old, when he went to work as a Conklin contractor. Over the course of his career, he’s installed hundreds of thousands of square feet of roofing systems, but he still has a special passion for where he started in roof foam and coatings, and is a founding member of The Roof Coaters Guild of America. Gregarious and outgoing, Eric brings a unique sense of fun to his work, whether he’s on a roof or in the office.
