The secret to metal roof durability

By H. B Fuller.

Discover how butyl sealants provide unmatched protection, extending the life of your metal roof through flexibility, adhesion and weather resistance.

Metal roofs are a powerhouse of durability, boasting lifespans that outlast most alternatives. But what if their endurance isn’t just about the panels themselves? Beneath the gleaming exterior lies a quiet hero — butyl tape and sealants from H.B. Fuller. These unassuming materials work tirelessly, weathering storms, sealing vulnerabilities and flexing with the metal’s natural expansion and contraction. Curious how such a simple component can hold the key to a roof’s decades-long resilience? Read on to uncover the science and strategy behind this unsung protector of metal roof longevity.

In this article, we look at butyl sealants and how they:

• Maintain excellent adhesion
• Offer flexibility at low temperatures
• Allow for heat expansion and cold contraction without losing flexibility and sealing power

How butyl tape protects metal roof assemblies

Butyl rubber sealants are known to be reliable for a variety of applications, requiring waterproof seals. They are an ideal companion product for metal roofs for many reasons, including performance over a long time. In addition, butyl sealants are highly versatile in usability: (source)

• Applied hot or cold
• Maintain excellent flexibility at very low temperatures
• Are weather and water-resistant

The following sections explore how butyl sealant’s application method, material flexibility and resistance to the elements improve metal roof longevity.    

Water wants to destroy your roof. Butyl sealant is not OK with that.

There are three primary areas where moisture can enter the substrate below the roof:

• Through fasteners that penetrate through the roof
• Through the flashing around chimneys and other protrusions  
• Through improperly sealed substrates

Water under your metal roof panels leads to corrosion and structural damage over time. Nobody wants to see rusty metal on their roof or to imagine it under the roof. However, butyl sealants form and maintain an effective barrier to water, preventing rust and maintaining structural integrity over time.  

Roofs get hot and cold. Butyl sealants remain sticky.

One of the primary benefits of butyl sealant is that it is non-skinning. Amazingly so — for years and years.

Non-skinning means that after the sealant is applied, it does not form a skin. Therefore, it maintains its original sticky, tacky, malleable form, in which it was applied.  

Because the sealant’s functionality remains constant over time, so will its ability to hold panels to the substrate. Butyl sealants can retain cohesive strength despite sustained fluctuations in panel temperatures as well. To demonstrate these abilities, refer to Figure 1. Even after 30 years, upon removal, the butyl sealant remains well adhered with an elasticity that is quite apparent (Figure 1). (source)

Figure 1. Butyl sealant demonstrated excellent elasticity on a Denver roof after 33 years.  

Roofing panels expand and contract. Butyl sealant is OK with that.

Non-skinning means that, sticky, tacky, malleable state is permanent even after exposure to air; the adhesive does not undergo a curing process that would change its physical state. Due to butyl sealants non-skinning abilities, it is able to absorb the stress and movement of the metal panels, allowing them to move as temperatures change. Therefore, the quality of sealant is critical.  

Metal roof longevity needs materials that work together

The life of a metal roof is extended by using materials that collaborate with the metal – each material doing what it does best. Butyl sealant remains tacky and sticky for years. Butyl tape is easily applied in long runs that can accommodate an entire metal panel.  

H.B. Fuller offers a range of butyl sealants, including heat flowable seam tapes, heat expandable seam tapes, high viscosity, non-sag pastes, as well as lower viscosity, flowable liquids to meet your every application need (Table 1). Extensive industry testing and field use have proven our butyl sealants maintain excellent adhesion to a wide range of substrates. Our butyl sealants are used and trusted in several commercial markets, including metal building, automotive HVAC, transportation, marine and industrial assembly.

Table 1. H.B. Fuller Butyl Sealants

Contact H.B. Fuller to learnmore about how butyl sealants can extend the life of your metal roof.  .  

Original article and photo source: H. B. Fuller