Commercial Roof Options for Existing Metal Buildings

Over the past 50 years, metal buildings have been extremely popular across the U.S., specifically in the Southeast. This is because metal buildings are typically more cost-effective than traditional wood-framed and concrete structures.

With a metal building project, one contractor is typically responsible for the entire job. This means that the contractor’s team will install the building foundation, erect the steel structure and finally install the siding, roofing, and everything else in between. 

The design possibilities are perhaps limited with metal buildings, but if a building user is looking for a simple design with a limited budget, then a metal building is the most effective solution.

Metal buildings are durable and can last for decades, providing strength and a sleek look, especially for industrial buildings. In terms of resilience, metal roof and wall panels can withstand powerful sustained winds, perfect for coastal regions with harsh weather. The problem with metal buildings is that they are made out of steel, and steel rusts. This is especially an issue in the Southeast. For example, the region between Daytona Beach, Florida, and Savannah, Georgia has the greatest salinity level in the entire country. 

The durability of a roofing system hinges on its ability to resist rust and corrosion. Rust and corrosion reduce a metal roof’s ability to keep out moisture, diminish its aesthetic appeal, and shorten its lifespan. The exterior cladding on metal buildings will fail over time if not properly maintained. Some of the actions you can take to combat damage to your metal roofing system are as follows.

1. Protective Roof Coating

When you start to notice signs of deterioration to your roof, you’ll want to take urgent action. A metal panel typically contains a clear or colored finish coating, but over time this coating wears off. This will lead to surface rust generation, specifically at any cut metal edges or fastener penetrations. Before the rust deterioration begins to totally degrade the roof panel, a roof coating can be applied to provide a protective layer against the elements. 

First, the roof must be power washed to remove any debris or loose coatings. Depending on the level of deterioration a roof panel contains, a rust-inhibiting primer may be applied to neutralize the oxidation process occurring in the steel. After the primer application, any seams or fastener penetrations are sealed with a flashing grade product, which is a thicker product that will offer additional protection at these critical locations. Lastly, either one or two coats of roof coating are applied, providing the final protective finish.

There are several types of roof coating chemical formulations, but the most common are acrylic (also known as elastomeric or water-based) coatings and silicone-based coatings. Acrylic coatings are good options for metal roofs with positive roof slope. Silicone coatings are typically used on flat roofs or any roof condition where poor roof drainage is present.

Roof warranties for coatings can be tricky. Every product you purchase will come with a material warranty, which is basically worthless. Some manufacturers offer labor and material warranties that guarantee any leaks over a 10,15 or 20-time period will be repaired at no cost to the owner.  The tricky part is the exclusions of a coating warranty. The substrate is excluded, meaning if the roof expands/contracts or a fastener backs out, causing a breach in the coating, then the warranty claim is excluded. 

A roof coating or recoating is probably the most economical type of roof system you can put on an existing metal roof panel. This option offers a long-lasting, simple-to-maintain roofing solution without the time, expense, inconvenience, or safety concerns of entirely ripping off and replacing a roof. It is imperative to consult a qualified roofing contractor or design professional to qualify your roof to receive a roof coating.

2. Flute Fill Single-Ply Roof Recover

Do you have an old metal building that has a lot of exposed fasteners on it and you’re tired of having to replace them only to find they are leaking once more? Or perhaps you’ve used a coating before and weren’t satisfied with the results? Instead of trying to patch the problem again, you would probably want to add a complete roof system on the metal building to keep this cycle from happening. In this situation, we would recommend a Flute Fill Single-Ply Recovery. 

The flat part of a metal roof panel, between the high ribs, is considered the “Flute.” To perform a flute-fill roof installation, you’re going to:

  1. Fill the flutes in the metal panel with pre-cut insulation.

  2. Add another layer of insulation over the base layer, to create a level surface.

  3. Install a single-ply roof membrane and secure to the steel building framing.

This has become a very popular roofing system over the last ten years. The advancement of technology has allowed for a certain type of TPO or PVC roof attachment method which is called Rhinobond. This technology, created by OMG Roofing Products, allows for induction welding of the roof membrane to the building structure.

To successfully enforce induction welding, you’re going to have to install the insulation board along with a fastener and a metal plate and screw it into the building purlins or joists. The top of the metal plate will be coated with liquid TPO or liquid PVC. 

From there, you will need to kick out your rolls of single ply on top of it and run the Rhinobond with the OptiWeld Technology Machine. The machine then triggers the heat to transfer down to the top of the TPO or PVC to the bottom and it fully welds and bonds the bottom of the sheet to the plate that is coated with liquid TPO or PVC. 

The ease of this style of adding a new roof system to an existing metal building has only emerged in recent years. Before, contractors were doing these types of roof overlay systems but they were just attaching the new roof system to the existing metal panel. A lot of metal buildings were designed and built in the ’70s, ’80s, and ’90s, and building codes aren’t what they are today. So the problem here is if you were to attach it to the old roof – how well do you know that the old roof is attached to the building? 

This roof advancement has allowed a very economical way to overlay metal buildings and obtain high wind uplift for a new roof system. This method saves time, decreases landfill waste, and quickly waterproofs your commercial structure. Another benefit is that the addition of roof insulation will increase the thermal efficiency of your building.

3. Re-Roof

Often, metal panels can be fixed to address excessive leaks and other issues. However, once a roof panel contains a level of deterioration that will not allow a roof coating or a single-ply flute fill overlay, then replacement is the only option. 

Replacement metal roof systems can be either concealed or exposed fastener applications. Concealed fastener applications, like standing seam panels, are superior due to the fact they conceal any cut edges or fastener attachment points. This prevents the components from deteriorating. Exposed fastener roof panels have much lower cost, but will result in more long-term maintenance requirements.

Be sure to consider all the indicators that could suggest that your metal roof needs to be replaced. You may incur expenses for repairs, suffer property losses, or even lose stock or equipment due to increasing damage to your roof. Re-roofing sooner rather than later could greatly save your building from a long-term financial impact. 

What kind of metal roof repair does my commercial building need?

Knowing when to recover or replace a metal roof is crucial. Regular roof inspections are one way for company owners to prevent more serious roofing issues. If your metal roof is beyond basic repairs due to panel deterioration, you may want to consider getting a full replacement.

At Register Roofing, we have offered commercial roofing solutions in the Southeast for more than 40 years. We offer all three options mentioned in this article depending on your unique metal roofing situation. Contact Register Roofing today so we can provide you with a professional metal roofing solution.


Experience the Register
Roofing difference

Register Roofing

Request An Estimate