3 stages of metal roof maintenance

By Denise Tripamer, H.B. Fuller. 

Share this useful guide that outlines how to care for a metal roof, from installation to ongoing maintenance. 

Metal roofing systems are becoming increasingly popular due to their impressive durability and ability to resist the wear and decay other materials are prone to. In fact, they can last over 60 years, withstanding severe weather. This performance is not predicated on the panels alone; the quality of the accessory materials — the adhesives, sealants and other chemical products — is essential to the service life of a metal roofing system.  

Here at H.B. Fuller, we want to help roofing contractors and building owners choose the best materials for greater optimization for a metal roof’s entire life cycle. This guide includes:  

• How butyl tape increases the longevity of your roof 
• Best practices for applying sealant 
• How sealants like EternaBond®  easily repair leaks that may occur 
• How to decide between replacing and repairing your damaged roof 
• Ongoing maintenance tips 

Stage 1: Proper metal roof installation prevents problems 

Installing a metal roof using long-lasting materials helps reduce the need for repairs and maintenance. While storm damage is uncontrollable, leaks from vulnerable areas, such as edges, fasteners at seams and flashing around chimneys and other protrusions, can be prevented. 

Butyl tape prevents leaks at metal roof seams 

A study conducted by the Metal Construction Agency on the service life of metal roofs found that sealant was the deciding factor in the service life of a metal roof. Researchers inspected metal roofs, sealed with butyl sealants, across the US and used an independent laboratory to analyze materials. They found no deterioration in tensile strength in the sealants, estimating that butyl sealant service life could last over 60 years. 

Choosing materials like butyl tape, which is proven to have long-lasting strength, is key to preventing costly problems in a roofing assembly. Butyl tape for sealing metal panels is non-skinning, meaning it doesn’t create a membrane after application and remains tacky and flexible throughout its lifetime. This allows the sealant to flex with any movement of the metal panels — it is also easier to apply evenly than other types of sealants. 

Butyl seam tapes create a waterproof seal between two overlapping panels. In this assembly, the butyl tape can perform its duties over the life of the roof. Because these tapes don’t form a protective (skinning) layer, they cannot go on the top of panels — where they would be exposed to environmental conditions which would deteriorate the tape’s effectiveness. 

For instances that need to withstand those conditions, select either a skinning butyl tape or other products, such as  EternaBond® repair tapes or FulaFlex® hybrid sealant lines by H.B. Fuller — both are ideal for topical sealing, repair and maintenance tasks.   

How to apply butyl tape to your metal roof 

1. Roll out the tape. Butyl tape comes in different-sized strips. Since it doesn’t require caulking, estimating how much material you need is easier and ensures an even application. 
2. Clean panels thoroughly using soap and water. Any residue from shipping or processing, such as oil, can limit the product’s effectiveness. 
3. Allow panels time to dry. 
4. Apply tape over the whole line evenly, without gaps. 
5. Put pressure on the tape to ensure it makes contact with the material. 

Stage 2: Make repairs with long-lasting sealants 

Metal roofs may become damaged by wind or hail during storms, or if materials used in vulnerable areas degrade. Aluminum metal roofs, such as those used on recreational vehicles (RVs), semi-trailers and box trucks, are more likely to require repairs than metal roofs made of other materials. This is because aluminum is more vulnerable to oxidation and stress cracks. 

How EternaBond® tape creates leak-proof sealing 

Topical sealants like H.B. Fuller EternaBond® RoofSeal™ semi-permanent roof repair tapes are ideal for leak-proof sealing on damaged roof panels or flashing. EternaBond® products use MicroSealant® technology formulated with synthetic polymers and a built-in primer. MicroSealant® forms a stable molecular structure that can bond instantly to most substrates, creating a waterproof seal resistant to light, heat and environmental factors. 

In addition to instant sealing and leak protection, EternaBond® benefits include: 

• Easy, no-mess application 
• Low-temperature flexibility to -57°C (-70°F) 
• No shrinkage 
• Seals in harsh environments (-40°F to 150°F) 
• Comes in multiple sizes and colors 
• Remains flexible for decades 

The EternaBond® family of tapes can be used in many different ways. Jacque Ince, an H.B. Fuller Senior Product Manager, explains: “Depending on what type of backing you need for your restoration or repair projects based on the type of metal roof, we have a lot of EternaBond products that cater to those needs.” 

When to repair versus replace a metal roof 

At a certain point, metal roof owners may have to decide between repairing damage to their roof or replacing it entirely. This decision is best made with the help of the metal roof manufacturer and depends on the general condition of each panel and whether the metal roof is on a commercial or residential building. 

When damage is limited to one part of a panel, repairing the panel with EternaBond® is a cost-effective, durable solution. However, if an entire panel is severely damaged or the roofing assembly must be taken apart to make repairs, replacing the entire roof is often more cost-effective. Commercial property owners may choose to build a second metal roof over the damaged one if it can’t be repaired. 

Step 3: Metal roof maintenance 

The first step in metal roof maintenance is simple: visually inspect the roof. Look for rust, warped panels and signs of moisture buildup. Accessing your roof for inspection must be done carefully to avoid falls. The Metal Roofing Alliance recommends hiring a professional for ongoing roof maintenance tasks to ensure safety. 

In addition to visually inspecting the roof, periodic cleaning will help reduce damage from pollution, dirt and debris from organic material. Since metal roofs are not prone to mildew, they can be cleaned just like a vehicle — with mild detergent and water. Experts at the Metal Roofing Alliance advise applying cleaning solutions with non-abrasive materials and always following manufacturer recommendations. 

A third element of ongoing metal roof maintenance is remaining mindful of any additions to the roof. Metal roofs may become damaged during the installation of equipment like solar panel systems. Checking with the manufacturer before installing anything onto your metal roof is critical to preventing damage. 

Conclusion: Range of metal roof sealants from H.B. Fuller 

Metal roofs are often billed as a low-maintenance, long-lasting, environmentally friendly alternative to traditional asphalt roofs. While this is true, proper installation, ongoing maintenance and repair with quality materials can extend the life of your roof. 

In addition to the two solutions covered in depth above (EternaBond® and butyl tape), H.B. Fuller offers a wide range of products for use in metal roofs (Figure 1). Applications include topical sealants, exterior repairs, vapor sealants, wall joint adhesives, pole-setting products and more. 

Figure 1. H.B. Fuller metal building sealants 

Effective sealants help ensure the service lifetime of your metal roof. Contact an H.B. Fuller expert to explore which sealants are best for your application. 

Original article and photos source: H.B. Fuller