Smart Winter Design for Modern Construction
Why builders should consider pre-engineered metal buildings for today’s evolving snow and ice conditions
Winter Has Changed, and Buildings Are Showing It
Recent winters have brought unprecedented snowfall totals, sharp lake effect bursts and mixed precipitation that layers rain on top of existing snow and ice. These patterns are stressing older buildings that were never engineered for today’s conditions and exposing weaknesses in designs that assume even snow distribution.
Several recent failures highlight this shift, including school and commercial roof collapses in Ohio and New York, along with damage in regions that rarely see heavy snow such as Tennessee, Mississippi and Texas.
The National Oceanic and Atmospheric Administration (NOAA) continues to track this broader trend through the Storm Events Database, the National Snow and Ice Monthly Reports and the National Snow Analyses portal.
How Winter Roof Loads Actually Affect Buildings
Winter roof issues rarely result from a level, uniform layer of snow. Problems typically come from concentrated weight caused by wind, roof geometry, temperature changes and drainage blockages.
1. Uneven Accumulation and Drift
Wind pushes snow into parapets, roof steps, valleys and behind mechanical units. These drifts can be several times heavier than surrounding snow and may create unbalanced loading if not properly addressed during design.
2. Sliding Snow and Lower Roof Impact
Upper roofs sometimes shed snow suddenly. The lower roof then absorbs both the impact and the long-term accumulation that follows. If the lower structure was not designed for these combined loads, damage is likely.
3. Rain on Snow and Rapid Load Increase
When rain saturates existing snow, the weight increases quickly. Modern codes treat this scenario as a specific design case because many failures occur during mixed precipitation events.
4. Ice Blocking Gutters and Drains
Frozen drainage components force meltwater to back up and refreeze. This can overload roof edges or create dense, heavy ice masses. On low slope roofs, refrozen ponding water becomes a separate load that older buildings may not have been designed for.
Metal Building Note: Gutter System Overload Protection
Ice related loads often concentrate at roof edges. For that reason, modern metal building gutter systems typically include built in safeguards. Gutters are attached to roof panel straps with engineered breakaway connectors that release if the gutter becomes overloaded by ice, compacted snow or frozen meltwater.
This controlled release helps protect roof panels and fasteners from forces they were not designed to carry. After detachment, the gutter can usually be reattached or replaced with minimal repair work.
FEMA’s Snow Load Safety Guide is a useful resource for field teams, summarizing warning signs of overstress before, during and after winter storms.
Download the guide HERE.
Why Some Buildings May Be More Vulnerable
Many existing buildings were designed using older snow maps and design tools that did not fully account for drifting, uneven loading or rain falling on snow. Updated codes incorporate modern data and provide clearer guidance for these conditions.
However, not every jurisdiction has adopted the latest updates. Even in those cases, using current best practices can improve winter performance and reduce callbacks.
Why Pre-Engineered Metal Buildings Perform Well in Winter
Pre-engineered metal buildings (PEMBs), when engineered to current code criteria, are tailored to the site, the roof geometry and the likely drift and sliding zones. Frames, purlins and connections work as an integrated system rather than relying on generic prescriptive assumptions.
The MBMA Metal Building Systems Manual, aligned with the 2024 IBC and ASCE 7 22, includes worked examples for snow, rain and drainage design.
PEMB roofs shed snow efficiently at appropriate slopes. Engineers anticipate where snow will accumulate on lower levels and reinforce those areas. This coordinated design approach helps PEMBs avoid many of the winter related performance issues seen in other structures.
Field Detailing That Helps Prevent Winter Callbacks
- Parapets and Roof Steps
Treat these as drift collectors. Verify bracing, connections and panel attachment. - Eaves, Gutters, Scuppers and Internal Drains
Keep drainage paths open. In freeze prone areas, consider heat tracing and redundant drainage. - Lower Roof Catch Zones
Confirm capacity for both the impact and sustained accumulation that result from upper roof shedding. - Snow Retention Devices
Use only when supported by engineering. Retention changes upstream load behavior.
Existing Buildings: What To Recommend
For older or distressed buildings, direct owners to a licensed structural professional. They can recommend targeted upgrades such as reinforcing frames or connections, adjusting secondary members or improving drainage and roof edge details. MBMA provides additional retrofit resources.
Builders should avoid advising owners on snow removal or trying to diagnose loading issues. These decisions require professional engineering analysis.
Before the Storm: Free Checklist for Your Customers
You can share this Winter Storm Readiness Checklist with building owners to help them prepare before the season begins. It provides simple steps that prevent minor issues from developing into major winter problems.
The checklist helps owners:
- Confirm gutters, drains and downspouts are clear
- Identify drift prone areas such as parapets or roof steps
- Decide whether heat tracing is necessary
- Understand what to watch for during storms
- Recognize after storm warning signs such as sagging, sticking doors or ice at eaves
- Know when to restrict access and contact a structural professional
Talking With Owners About Winter Risk
Owners benefit from having a clear explanation of how winter conditions affect a building, especially during storms that bring drifting, mixed precipitation or rapid freeze and thaw cycles. FEMA notes that concentrated pockets of snow and ice near roof features often cause more stress than the total storm snowfall.
A simple one page handoff sheet with warning signs and drainage reminders is an effective communication tool. FEMA’s Snow Load Safety Guidance flyer is an excellent companion resource.
Why Builders Who Do Not Use PEMBs Should Re evaluate
Builders who work with conventional steel, wood, CMU or hybrid systems should consider the advantages of PEMBs. Modern PEMBs use updated snow maps, account for drifting and unbalanced loads and integrate roof and drainage design from the start.
The MBMA Manual for 2024 aligns with IBC 2024 and ASCE 7 22, reinforcing these methods. 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.
Metallic Building Systems Authorized Builders also benefit from myPortal, an integrated online platform that incorporates current load requirements, provides real time pricing, tracks orders and streamlines project coordination. This helps builders work efficiently while ensuring compliance with modern winter load expectations.
Winter Conditions Are Changing, and Buildings Must Adapt
Winter storms are becoming less predictable, and buildings face snow and ice patterns that differ from those of the past. Builders who understand drifting, sliding snow, rain on snow and freeze and thaw cycles can help owners protect their investment.
Pre-engineered metal buildings offer a strong, reliable solution when detailed and installed according to engineering. By using updated load criteria and communicating clearly with owners, builders can deliver structures that perform confidently through winter weather, year after year.
Build With Confidence
If you want a building solution designed for today’s winter conditions, Metallic Building Systems can help. Our pre-engineered systems, supported by the accuracy and efficiency of myPortal, give builders a streamlined way to deliver winter ready projects.
Get a quote from Metallic 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