Common Issues That Could Affect Your Metal Roof

Metal roofing has revolutionized the roofing industry. With excellent durability, an impressive aesthetic, and low maintenance requirements, a quality metal roof has its benefits. No roof covering, however, comes without potential problems. In this article, we look at 7 common issues that could affect your metal roof, and how to prevent them before they happen.

1. Roof Leaks

Roof leaks in metal roofs are unlikely, but not impossible. Given enough driving rain and gale-force wind, even the best quality metal roof may develop a water leak. In other instances, a leak may occur because of a roofing installation error. These errors can include:

Failed Seams

The seam or side rib is where the two roofing panels are connected. When a seam isn’t connected properly to a roofing panel, a leak can result.

Failed Fasteners

Fastening screws should always be installed with the perfect amount of tightness. If they’re underdriven or overdriven, you could be affected by a leak.

Underdriven screws don’t provide enough of a seal, whereas overdriven screws can deform the metal panel, creating a gap for water to get in. Screws that are installed off-center, or skewed, can also lead to leaks by not creating a proper seal. But more about fasteners later.

Deteriorating Flashing

Flashing prevents moisture from infiltrating joints around your roof. Flashing requires a sealant and a flawless installation if it’s going to protect against water leaks.

Inferior Installation Job

Choosing the right roofing contractor is paramount, as metal roof installation mistakes are common among inexperienced roofers. Your roofer should always follow the manufacturer’s standards and not take any shortcuts. You often won’t realize a substandard installation job until a few years down the line, and potentially thousands of dollars later.

2. Corrosion & Rust

Metal roofs can be susceptible to corrosion for several reasons, including:

Lack Of Protective Coating

Protective sealant coatings are designed to protect your metal roof from the elements. If the coating isn’t up to standard or has been omitted, your metal roof may be compromised.

Chemical Reaction

Your metal roof can occasionally come into contact with corrosive chemicals such as pesticides, fertilizers, and possible cleaning agents. Chemicals in these products can aggravate and accelerate corrosion.

Underside Rusting

Sometimes only the top side of the metal roofing is coated, leaving the underside vulnerable. Over time, trapped water molecules underneath your roof can lead to premature corrosion.

Exposure To Salt

Living along the South East Coast of Florida means that your metal roof will have to contend with constant salt in the air. It’s imperative that you get a high-quality anti-corrosive metal roof installed to ensure longevity.

3. Oil Canning

Oil canning is when a visible waviness becomes apparent around your flat metal roofing areas. It’s a buckling that occurs on standing seam metal roofing systems. Oil canning happens when your sheets are over-stressed and can no longer hold that flat appearance that we’ve come to love about metal roofs.

There are a couple of possible causes of oil canning, including:

• Inadequate space allowed for thermal expansion and contraction of panels.
• Over-production and extreme pressure being introduced during the metal coiling process.
• Improper storage and installation.
• Stress caused by coil slitting or cutting of metal panels.

Be sure to speak with your roofer about what preventative steps they can take to protect against oil canning.

These can include:​​​​​​

• Using thicker metal.
• Adopting a rib roller profile (striated) to help minimize large flat spaces on the panels.
• Installing your roof over a flat roof deck.
• Choosing a matte finish to reduce reflection and lower the visibility of any oil canning.

4. Scratching & Scuffing

Metal roofing isn’t immune to scratching and scuffing, which is why the utmost attention needs to be given to the handling process.

Precautionary handling steps should include:​​​​​​

• Correct coiling techniques to prevent metal from rubbing together.
• The use of edge guards and proper lifting devices while in transit.
• Minimizing of foot traffic on metal sheets.

A licensed roofing contractor will ensure that all requirements and standards are upheld in the sourcing of their metal roofing.

5. Thermal Contraction & Expansion

Thermal expansion is a commonplace occurrence in the South Florida sun, causing roofing to undergo some expansion and contraction. As the night cools, the sheets will then contract, leading to an ongoing cycle. An experienced South Florida roofer will be sure to make allowance for expansion and contraction.

When allowance isn’t made for these slight movements, your roof sheets can undergo severe stress, leading to possible buckling and warping. Your roof could also be subjected to loosening, causing gaps that could lead to water leaks.

6. Chalking Or Fading

Chalking is when a white residue forms on a coated metal panel that is caused by paint resin deterioration. The culprit of this breakdown is UV exposure. Another process known as fading is when the paint pigment breaks down. This causes your paint finish to change color and fade. This can happen when your roof panels aren’t evenly exposed to the sun.

Trusted roofers will insist on only the best quality paint and sealants that offer warranties on their lifespan and color protection.

7. Missing Or Loose Fasteners

Over time, roof fasteners can loosen and even dislodge. This can be due to expansion and contraction, as well as ongoing environmental exposure. When fasteners become loose, the integrity of your metal roofing can be compromised. Panels may not be as securely attached, causing them to be vulnerable to wind uplift during a storm. The risk of water infiltration is also increased due to gaps, placing your roof deck and interior at risk of water damage. Repairing a hole in your roof should always be prioritized to prevent further leaking.

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