Why should all builders consider pre-engineered metal buildings for today’s snow and ice conditions?  

Winter Has Changed and Buildings Are Showing It 

Recent winters have delivered record or near record snowfall, intense lake effect bursts and mixed precipitation that creates rain on snow and ice loading. These conditions are overstressing older buildings that were never engineered for today’s winter patterns and they are exposing the weakness of designs that assume uniform snow depth. Multiple recent incidents illustrate this trend, from school and commercial roof collapses in Ohio and New York to failures during rare heavy snow in Tennessee, Mississippi and Texas. 

The National Oceanic and Atmospheric Administration (NOAA) has also documented this broader pattern. The United States has experienced costly winter storm events in recent years, which are tracked through NOAA’s Storm Events Database and agencies continue to monitor winter extremes through their National Snow and Ice Monthly Reports, along with detailed national snow data provided by the National Snow Analyses portal. 

How Winter Roof Loads Really Act on Buildings 

Most winter roof problems do not come from a uniform blanket of snow. They come from concentrated pockets created by wind, geometry, temperature and drainage. 

1. Uneven Accumulation and Drift
   Wind drives snow into parapets, higher to lower steps, valleys and behind rooftop obstructions. These drifts can be several times heavier than surrounding snow and produce unbalanced loading that exceeds capacity if it was never considered in design.  
2. Sliding Snow and Lower Roof Impact
   Upper roofs can shed suddenly. The landing zone on the lower roof experiences a sudden duration impact and then sustained accumulation. If the lower roof and its supports were not designed for that combination, localized damage is common.   
3. Rain on Snow and Rapid Weight Increase
   When rain saturates an existing snowpack, weight rises quickly. Modern guidance treats rain on snow explicitly because many failures follow mixed precipitation events.  
4. Ice Blocking Gutters and Drains
   When meltwater hits frozen drainage components, it backs up and refreezes. This buildup can overload roof edges or trap water that later freezes into a dense, heavy mass. On low‑slope roofs, ponded water that refreezes becomes a separate load entirely, one that may not have been anticipated during the building’s original construction. 

Metal Building Note: Gutter System Overload Protection 

Because these ice‑related loads tend to concentrate at roof edges, most modern metal building gutter systems include a built‑in safeguard to help protect the structure. When properly installed, gutters are attached to the roof panel strap with connectors engineered to release if the gutter becomes overloaded, whether from heavy ice accumulation, compacted snow or trapped meltwater that freezes solid. 

This intentional breakaway design prevents excessive weight from transferring directly into the roof panels or their fasteners. Instead of forcing the roof edge to carry loads it was never designed for, the system allows the gutter to detach in a controlled, predictable way. This helps avoid deformation, panel damage or structural stress that might otherwise occur. 

After detachment, the gutter components can typically be reattached or replaced with minimal repair work, preserving both roof integrity and long‑term drainage performance. 

For field teams, FEMA’s Snow Load Safety Guide summarizes warning signs of overstress and outlines prudent actions before, during and after winter events.  

Download the Guide HERE. 

Why Some Buildings may be at Higher Risk 

Many existing buildings were designed using older snowfall data and older design tools that didn’t fully account for how snow really behaves on roofs. Newer codes use updated snow maps and better guidance on things like drifting, uneven loading and rain falling on snow, which helps engineers design for what actually happens during today’s winter storms. Not every jurisdiction has adopted these updates yet, so builders may still encounter plans based on prior information. Even in those cases, following current best practices in the field can help the building perform better and reduce winter related callbacks. 

Why Pre-Engineered Metal Buildings Meet Winter Conditions Well 

Pre-engineered metal buildings, when ordered and engineered to current code criteria, are tailored to the site, the roof geometry and the likely drift and sliding locations. Frames, purlins and connections are sized as an integrated system and are not relying on generic prescriptive assumptions. The MBMA Metal Building Systems Manual now aligns with the 2024 IBC and ASCE 7 22 Code and includes worked examples for snow, rain and drainage design.  

PEMB metal roofs can shed snow efficiently on appropriate slopes. Good design anticipates where that snow will accumulate on lower roofs and places capacity at the catch zone. This systematic approach is one reason PEMBs tend to produce fewer winter surprises when they are installed according to the construction drawings and properly maintained.  

Field Detailing That Help Prevent Winter Callbacks 

1. Parapets and Steps
   Treat these as drift collectors. Verify bracing, connection capacity and panel attachment at these lines per the drawings.  
2. Eaves, Gutters, Scuppers and Internal Drains
   Keep pathways open. In freeze prone zones, consider heat tracing and redundant drainage. MBMA’s snow removal appendix explains how blocked drainage can create extreme edge loads.  
3. Lower Roof Catch Zones
   Where upper roofs shed onto lower roofs, confirm the lower roof members, deck, and supports are designed for both impact and the sustained downstream accumulation.  
4. Snow Retention Devices
   Use only when engineered for the roof geometry. Retention changes how and where load accumulates upstream.  

Existing Buildings: What To Recommend 

For older or distressed buildings, the safest and most appropriate guidance is to direct owners to a licensed structural professional. A professional may evaluate the building and recommend targeted upgrades such as reinforcing frames or connections, adjusting secondary members or improving drainage and roof edge details. MBMA provides retrofit resources that can help teams understand common upgrade options. Beyond this, builders should avoid giving advice about removing snow or attempting to diagnose winter loading issues. Those decisions should be made by qualified engineers who can assess the building’s condition and ensure any actions are safe and appropriate. 

Before The Storm: Free Checklist Download for Your Customers 

You can share this Winter Storm Readiness Checklist with your building owners and facility teams to help them prepare their buildings before winter weather arrives. It gives owners a clear, practical list of what to check ahead of the season, so small issues don’t turn into winter storm problems. 

The checklist helps owners:
• Make sure gutters, drains and downspouts are cleared and working. 
• Identify areas where snow may drift, like parapets or roof height changes. 
• Decide if heat tracing is needed for freeze prone drainage. 
• Know what conditions to watch for during storms, such as drift buildup or rain on snow. 
• Spot simple after storm warning signs like sagging rooflines, sticking doors, unusual noises or ice at eaves. 
• Understand when to restrict access and call a licensed structural professional. 

Talking With Owners About Winter Risk 

Owners benefit from having a clear understanding of how winter conditions affect a building, especially during storms that bring drifting, mixed precipitation or freeze–thaw cycles. FEMA notes that roof stress often comes from heavy pockets of snow and ice forming at roof features, not from the overall storm total. Heavy, wet snow, rain falling on existing snow and blocked drainage can increase roof loading much faster than many people expect.  

A practical way to support owners is to provide a simple one-page handoff sheet that outlines general warning signs, basic drainage checks and when to contact a licensed structural professional. FEMA’s Snow Load Safety Guidance flyer includes straightforward indicators of overstress, such as unusual noises, new roof sag or doors and windows that suddenly stick and can be a helpful companion to any internal readiness materials you share. 

Why Builders Who Do Not Use PEMBs Should Re-evaluate 

If you build with conventional steel, timber, CMU or hybrid systems, consider the overall advantages of PEMBs for many types of applications. Modern PEMBs start with current snow maps and reliability targeted loads, model drifting and unbalanced snow conditions while also integrating the roof system and drainage planning from the start, reducing design gaps and field surprises.  

The MBMA Manual for 2024 aligns with IBC 2024 and ASCE 722, reinforcing these updated approaches. For builders who want a clear explanation of how today’s snow and rain load provisions differ from older approaches, this overview is a helpful reference. Star Building Systems Authorized Builders also benefit from myPortal, an all-in-one online platform that automatically incorporates current load requirements and design expectations into each project. myPortal provides real-time pricing, order status, project coordination and account management in a single workspace, helping builders work more efficiently while ensuring their building inputs reflect modern winter load considerations.  

Winter storms are becoming more unpredictable, and buildings of all types are being asked to handle conditions that look different than they did even a decade ago. Builders who understand how snow, ice, rain on snow and drifting really act on a roof are better positioned to help their customers avoid problems and protect their investment. Pre-engineered metal buildings provide a modern, reliable way to manage these winter demands, especially when they are detailed and installed according to engineering. By staying aware of updated load expectations, using current best practices and sharing clear information with owners, builders can deliver projects that perform confidently through winter weather, season after season. 

If you are looking for a building solution that is designed with today’s winter conditions in mind, Star Building Systems can help. Our pre-engineered systems, backed by the efficiency and accuracy of myPortal, give builders a streamlined way to deliver strong, winter-ready structures. 

Get a quote from Star Building Systems today and see how our solutions can support your next project. 

Want to learn more? Listen to our Metal Minutes Podcast: Winter-Ready by Design: How PEMBs Help Deliver in Snow, Ice and Extreme Cold