Tag: ice dams

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

Posted on by Ken Buchinger

What to consider when designing and building in snow-prone areas.

While properly-designed metal roofs historically perform well in winter, heavy snowfall can be detrimental to buildings of all kinds. Those who live and work in and around them are also at risk when snow and ice cause dangerous situations. Even though winter doesn’t formally begin until late December, colder weather is upon us. And while you might not be expecting snow or ice yet, keep these roofing and snow tips in mind when designing, constructing and maintaining structures in areas where there’s a chance for snow and/or ice over the course of the year.

Considerations for Snow-Bearing Roofs:

  1. Anticipate Snow Load

Snow accumulates on every roof type, and as this happens, it increases the amount of weight your structure is bearing. This increased weight (snow load) can pose several threats to the structure and those in and around it. For example, when the weight of snow or ponded water from melted snow exceeds the structure’s limits, the roof or even the entire structure can collapse. Be sure you’re aware of the weight your structure can bear and remove snow to keep it within its limits. Consult the International Building Code (IBC) as well as state and local codes for guidance based on your location.

  1. Prevent Ice Dams

Most ice dams are the result of air barrier flaws in buildings. If warm indoor air escapes through the roof floor, it warms the roof sheathing and melts the underside of the layer of snow on top. This water then moves down the slope of the roof toward the eaves, where it freezes into ice. As this process continues, the ice gets thicker and thicker, resulting in ice dams. The presence of these dams allow water to back up and form a reservoir that can cause major damage.

To prevent ice dams, you should:

  • Seal all air leaks at the attic floor
  • Ensure proper insulation
  • Provide adequate attic ventilation

Another tip is to use a peel and stick membrane on the roof deck extending from the eave to about 3’ up-slope from the exterior wall. For more specific details on the ice dam prevention tips above, read our recent blog post.

  1. Prevent Sliding Snow

Gravity can cause accumulated snow to slide down the roof’s slope (shedding), potentially injuring people and damaging property below. Despite this, snow shedding must occur to keep the snow load from accumulating beyond the buildings structural limits. Balancing snow load and shedding is important and requires that you consider geographical and building material and roof design factors.

ABC Roofing and Snow Blog
Ice and snow sliding down the main roof has damaged the roof panels and the valley trim on this connector roof.

Roof slopes of 45 degrees (12:12) or more, can accelerate sliding snow with sometimes immense and dangerous consequences. For example, if snow accumulates and then falls onto an exterior gas line, pipes could rupture. From there, the smallest of ignition sources could set the structure ablaze. In addition, the weight of sliding snow can propel any icicles formed on eaves can be propelled down by the force and weight of sliding snow onto people and property below.

On slopes less than 45 degrees (6:12 to 9:12), low amounts of friction (like on smooth roof surfaces) means it offers less resistance to sliding. Striations and embossing on roofing materials like metal panels add a small 3D profile and improve the resistance to sliding, especially when they run traverse to the slope.

This can get complicated, but in general, installing metal panels with snow retention devices on a steeply-sloped roof is recommended. This approach will naturally shed snow and ice, and protect your structure from excessive snow loads. If you have a low-sloped roof, be sure it’s design supports snow as shedding won’t occur naturally. Including enough snow retention devices from ridge to eave is also imperative for this design.

  1. Use Retention Systems

A variety of retention options, such as snow fences, bars or guards, are designed to make snow and ice melt completely or fall from roofs in small amounts. This helps reduce risks associated with sudden rooftop avalanches while maintaining the clean lines of the roof. It is important that snow retention systems are carefully engineered and properly installed. Models like S-5!’s snow-retention device design resource allow you to input your roof dimensions and expected snow load to adequately engineer snow fence assemblies.

  1. Protect Roof Attachments
ABC Roofing and Snow Blog_Pipe Protection
This pipe penetration is protected from sliding ice and snow by a small section of S-5! ColorGuard to the panel seams immediately up-slope from the pipe.

The weight of sliding snow can be powerful enough to take off attachments like exhaust vents. To combat this, reduce the shear load by installing rigid vent pipes securely and as high up on the roof slope as possible. If this is not possible, protect the pipes with a snow retention system.

While metal roofing responds well to harsh winter weather, it is imperative to take the time to keep snow, ice and moisture from causing issues. No matter the roofing design or material used, keeping people and property safe from overhead dangers should be a priority when designing, installing and maintain your structure.

In part two of this roofing and snow series, we’ll review additional considerations. It contains tips on roof layout, color, weathertightness and maintenance, which also play important roles in winter weather protection.

For more information on roofing and snow like 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.

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.