When Metal Roof Corrosion – When to Call an Expert?

Metal Roof Corrosion
  • Author: Fazal Umer
  • Posted On: March 11, 2023
  • Updated On: March 11, 2023

Most metal roofs consist of iron-based metal. So, frequent exposure to moisture and rain can result in corrosion or rusting. In short, corrosion is a type of defect in a metal roof. And if you have encountered such a scenario, it is time you consult a knowledgeable professional.

But Why Do Metal Roofs Corrode?

As a homeowner, you might understand a bit about metal roof rusting. But if you go by science, rust is an electrochemical process occurring on metal surfaces. They get exposed to electrolytes. Oxides will expand & occupy more space with rusting. The forces in the process damage the structure.

Besides, using a mixture of multiple metals on the roof may also lead to accelerated rusting. In short, combining metals contributes to interactions, resulting in the degradation & failure of your system. But to understand why rusting occurs; get an insight into the following narration.

Rust forms only when three elements are present in an order – iron, water, and oxygen. The prime cause of rusting is water, undoubtedly. When combined with oxygen, the moisture creates iron oxide or rust.

Steel structures may appear solid, but water molecules penetrate the microscopic pits. As a result, it cracks in the exposed metal. The oxygen further dissolves in water, forming a layer of rust. Put simply; rust corrosion is the attack destroying metal because of how it reacts to the environment. It occurs speedily with salty water and acid rain by the seaside.

Outlining The Types of Corrosion That May Affect Your Metal Roof

If you are seeking solutions for metal roof rusting, you first need to understand the types. So, before you type metal roof repair near me on Google, here are the three types of corrosion that may affect your metal roofs:

#1 Crevice Corrosion

It occurs when a tiny volume of stagnant moisture is next to the surface for a long timeframe. That makes moisture penetrate its protective coating. The crevice or crack should be large, so the moisture can enter, yet small to create a stagnant zone. Here are a few areas where crevice corrosion usually occurs:

  • In micro-cracks
  • In crevices beneath the fasteners’ heads
  • Beneath the gasket, where it may stay for longer
  • Between panels stored in the stack
  • The area where moisture gets trapped beneath the debris

#2 Galvanic Corrosion

This type of corrosion is an electrical process. When dissimilar metals remain connected by electrolyte, the metal will rust in the highest energy state. Electrons flow from the least noble to the noblest metal. This corrosion type is popular as galvanic corrosion.

Its severity depends on the moisture amount. Note that moisture in a coastal environment has salt. And salty water will conduct electricity better. Thus, it causes more corrosion.

#3 Filiform Corrosion

This type of corrosion appears as thin filaments just underneath the paints. However, at times, it may occur beneath the metal coatings too. Such a filament comprises an active head alongside a corrosion-product tail. The type depends on the metal type that’s corroding.

But filiform corrosion won’t weaken its structure.  Since it’s a cosmetic issue, rust usually starts at the panel edges and continues in a straight line. Filiform corrosion is common in environments with 65% to 90% humidity.  Humidity above 90% causes rust that appears as blistering.

Best Measures to Mitigate Dangerous Impacts of Metal Roof Rusting

Metal roof rusting is a common issue a homeowner might experience, especially in Spokane. Do you reside in Spokane and are currently in need of a metal roofing repair company? If yes, consult a professional who can deliver the right measures.

#1 Galvanized or Galvalume Roofing

Galvanized steel is a special steel type suitable for extreme weather conditions. Strength and affordability are two reasons why it is popular. But if you want something sturdier, Galvalume steel can stand the test of time well. This type of steel has a thinner zinc coating, showing signs of exposure speedily.

#2 Painting

Painting can also be an excellent repair solution to avoid rust in metal roofs. You can select any color that blends well with your building’s exterior and hue.

#3 Anti-Rust Finish

If your metal roof earlier did not have an anti-rust finish, consult the team of experts that can offer this service. Metal roofs that have an anti-corrosion finish will be long-lasting.

Considering the above repair solutions, it seems that Advance Roofing can keep the highest industry standards.

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Author: Fazal Umer

Fazal is a dedicated industry expert in the field of civil engineering. As an Editor at ConstructionHow, he leverages his experience as a civil engineer to enrich the readers looking to learn a thing or two in detail in the respective field. Over the years he has provided written verdicts to publications and exhibited a deep-seated value in providing informative pieces on infrastructure, construction, and design.