Tag: metal roof maintenance

Roofing and Snow: Everything You Need to Know – Part Two

Posted on by Ken Buchinger

Additional considerations for working with metal panels in winter.

In part one of our series on metal roofing and snow, we covered five of the most important elements to consider when preparing structures for winter weather. In this post, we’ll review four more ways to prevent unexpected, costly damage of metal panels in winter.

  1. Consider roof material and surface color

Metal roofs absorb heat quickly and radiate it effectively. Darker panel colors can enhance this solar absorption effect, which can save you money year-round. But because UV light can pass through 3-5 inches of snow, when combined with heat loss through the roof, it becomes more difficult for snow to stay solid. To minimize the chance of ice damming, you should ensure your roof system is properly sealed and insulated. If not, ice damming may occur and the melting and re-freezing of snow throughout the day can result in icy layers that promote snow sliding—no matter the roof material or color.

  1. Review weathertightness factors

For low-sloped roofs (less than 3:12), it is especially important for panel seams to be watertight to prevent water (melted snow) from leaking into the structure. This can be problematic when snow gathers and stays on a roof. Architects, designers and specifiers, therefore, should consider using panels that have passed the ASTM 2140 water head test or FM 4471 Appendix G water test. Water-resistant underlayment should also be considered for all roof slopes.

ABC Blog: Roofing and Snow: Everything You Need to Know about Metal Panels in Winter - Part Two
A close-up of this dormer roof illustrates how the impact of sliding ice and snow can damage panel seams.
  1. Consider your roof layout

Design elements like valleys and slope changes cause snow to collect and increases your snow load. Also, when dormers extend from a large roof area and one area is significantly bigger than the other, the structure is susceptible to experiencing unbalanced sliding snow. This imbalance can actually tear open standing seams and displace panels. Also consider that drifting snow may accumulate behind HVAC units, at perimeter walls, and behind solar and photovoltaic (PV) panels.

  1. Ensure Proper Roof Maintenance

One of the best ways to prevent snow and ice issues is to regularly inspect and maintain your roof. In addition to cleaning and inspecting your roof for possible issues, properly removing standing snow and preventing ice dams is a vital part of avoiding damage to your metal panels in winter. This often requires that you get into your attic to inspect for air leaks—the leading cause of ice dams. Read more about how to properly maintain and remove snow from your roof in this blog post.

If an issue is discovered, consult your roofing material manufacturer for recommendations as well as advice on warranty claims. Additionally, you can reach out to a trusted roofing professional in your area. These professionals can thoroughly inspect your roof system to help you determine ways to rectify any potential issues. You’ll want to do this before damage and/or injury occurs and before you pay for sub-par or ineffective repairs.

If you missed part one of this series, click here for our top five considerations. These include managing snow load and sliding snow, preventing ice dams, using retention systems and more! For more information on how metal panels fare in winter weather conditions and for advice on how to winter-proof your roof, reach out to an ABC representative today.

Metal Roof Pitch Part I: Engineering and Strength Considerations

Posted on by David Lester

Whether you’re an owner who needs to consider roofing material options because of the nature or design of your building, or a distributor/contractor whose job it is to recognize whether a suggested design will or won’t work based on a range of circumstances, it is critical to understand the engineering behind why roof pitch and tensile strength are important on a metal building project. In part one of our series, we look at the engineering and strength considerations that need to be taken into account when designing or specifying a building, while part two will review the best type of metal panel to use based on the pitch and end-use of your building,

Engineering Considerations:

Ideally, your roof pitch will be the “sweet spot” between having a roof pitch that’s so shallow that the beared load is increased and having a roof pitch that’s so steep that wind uplift probability is increased—a factor which can also vary based on the building width. Specific engineering considerations with regard to roof slope include:

  • Snow Load Requirements: lower slopes create more load that the roof/structure must support. For example, when you have a flat roof and it snows, the snow will stay on the roof, adding more weight; on a sloped roof, a good amount of the snow will slide off of the roof, so the load will remain in an acceptable range the structure can support.
  • Wind Load: Preventing roof damage from high winds is largely dependent on roof geometry, slope and building material used. If outside air is allowed to penetrate a structure through cracks and other openings when wind flows over a building, the air pressure beneath the roof assembly increases. When this pressure becomes greater than the pressure directly above the roof (which happens as wind flows over a building), this can cause upward force on the roof system, leading to loss of structural integrity and significant damage. Wind uplift rating and minimum slope requirements are dictated by building codes in the market, so be sure to check with your local municipality for specific details.
  • Water Diversion: the steeper the pitch the faster it will channel and divert water, preventing it from pooling and causing other issue like mold, mildew and paint degradation. As with the snow load considerations mentioned above, the less additional weight burdening the roofing system, the better.
  • Minimizing Debris: steeper-sloped roofs also help minimize the chance that debris, mold and mildew have to build up on the roofing system. Unless there is a catastrophic weather event that drops large amounts of heavy debris—tree branches for example—there is a small chance that debris on a roof of any slope will exceed its ability to carry the load. However, because the more debris is able to slide down and off of a metal roof, the less that needs to be manually cleaned. Additionally, access to and cleaning the eaves of sloped roofs is much easier and less time-consuming that trying to perform the same maintenance on a roof with less slope.

The Strength of Metal Panels:

  • Tensile strength: This refers to the panel’s ability to resist breaking when it’s placed under pressure or tension—meaning the panel has a measured ability to bend under a certain amount of stress before it snaps. Galvanized steel panels can withstand between 50,000 and 80,000 pounds of pressure per square inch (50 KSI – 80 KSI)—significantly higher than the tensile strength of other roofing materials. Despite this, metal panels remain lighter and more impact resistant, keeping the likelihood and cost of repairs to a minimum. Check the tensile strength of your metal panels with the manufacturer and be sure to reference common testing standards related to roof slope, including ISO ratings and ASTM standards that test tensile strength.
  • Steel Hardness and Density: While it can generally be assumed that thicker-gauge panels are stronger, the type of building construction, location and end-use can affect the choice in panel thickness. Buildings such as pole barns, post-frame buildings, warehouses and garages can require roof panels to span longer distances and therefore require thicker panels as they are more structurally sound. These thicker panels will also aid in reducing the chance of collapse under the weight of snow and water—particularly when the roof pitch is low. For smaller buildings—like residences—with supporting trusses and purlins that are typically closer together, thinner panels can be used in conjunction with thicker trim for an economic, structurally ideal residential metal roofing system. See our blog on metal panel gauges for more.

Conclusion:

Following common standards, doing adequate research and conforming to manufacturer guidelines regarding slope will ensure you’re reaping the full benefit of your metal roof panel selection. For more information on metal roofs and to learn more about recommendations on roof slope, contact your local ABC representative today.

Additional Resources:

For more information on slope requirements, visit NRCA’s website. For more information on steep-slope metal roofs and their benefits, visit the Metal Construction Association’s website.

Maintaining, Cleaning & Repairing Metal Panels

Posted on by Tyler Roose

Understanding the maintenance requirements of your metal panels is essential to maximizing the longevity of your investment with the least amount of hassle. While metal panels have been engineered to provide decades of trouble-free protection, they can suffer damage from the build-up of debris as well as storm-related traumas like hail stones, falling branches and ice dams. To extend the lifespan and strength of metal panels, maintenance consists mostly of preventing and correcting these issues.

metal roofing maintenance tips

 The importance of regular inspections

Regular inspections are critical to identifying damaged panels and accumulated debris that can trap moisture, causing corrosion over time. To prevent this, a visual inspection should be performed in the spring and the fall of each year, as well as after major weather events to identify issues. Take a walk around the structure and look for leaves, branches and other debris piled up on the roof, including in valleys, gutters and downspouts, as well as behind chimneys and/or other protrusions. While you can perform this type of inspection yourself, please keep in mind that metal panels—particularly metal roofs—should be professionally inspected every four to five years depending on your geographic location. If you live in a coastal or humid area more prone to corrosion and rust, professional inspections should be done more frequently to prevent the rust from spreading and causing structural damage to the panels.

In addition to debris, keep an eye out for scratched or dented areas, as well as for loose screws and seams that look like they are separating. (If you can’t make out the details from the ground, try using a pair of binoculars.). Use the manufacturer’s recommended touch-up paint to correct scratches as they can quickly degrade the surface protection and jeopardize the longevity of metal panels. If the panels have separating seams or holes, first check to see if the repair is partly or fully covered by your warranty. Unless you are experienced in metal roof repair and possess a thorough knowledge of the products and techniques that can be used without voiding the warranty, it is recommended that you engage a metal panel repair specialist to make the repairs. If you decide to undertake the work yourself, it is also important to remember that these fixes are, at best, temporary and should be addressed by a professional recommended by the metal panel manufacturer.

Cleaning metal panels

Keeping metal panels clean is one of the best ways to ensure they last as long as possible. When cleaning metal roofs and walls, using a non-pressure cleaning method with detergents recommended by the metal panel manufacturer is ideal. It is not advisable to use metal tools such as rakes to remove debris. This is likely to scratch the paint, reducing the panels protection from the elements and other damaging factors. Using a leaf blower to remove debris is a common choice, but a long-handled push-broom or a telescoping pole with a window cleaning brush will also do the job. Ideally, the tool should be one that lets you do the removal from the ground, but if you absolutely must walk on the roof then only step on the flat areas. If there are areas you can’t access yourself—particularly slanted areas that have been made slippery with cleaning solutions—hiring a professional service to do this once or twice a year is the safest option.

To reduce the chance of further damage and keep your panels cleaner over longer periods of time, trim tree branches as far back from the building as possible. This is especially important for large, unhealthy branches that could break off during high winds and cause damage.

Proper snow removal

There are—of course—considerations that must be made for metal buildings located in colder climates. After a winter storm, it’s a good idea to remove standing snow from the roof. This is doubly important on older homes where poor attic insulation can lead to ice dams. An ice dam forms when heat escaping from inside the attic warms the roof and melts the bottom layer of snow. The snowmelt then re-freezes, creating a dam that traps water which can work its way into seams between panels and around flashings.

Warranty considerations

It’s always smart to reference the metal panel manufacturer’s warranty to be sure you don’t use any products or tools that will void your warranty. They should also provide instructions and advice specific to the panels and application(s) you’ve selected to ensure you get the most out of their products with the least hassle.

For more information on metal panels, check out ABC’s FAQ page. For more on our metal panels and accessories, please visit our product pages or contact your local representative today.