Winter Condensation Issues on Industrial Flat Roofs

How to Inspect and Maintain Your Flat Roof in Cold Weather

Flat roofs on industrial, commercial and residential buildings require regular inspections to perform at optimal levels. One to two assessments per year in spring and fall is an ideal timeline; however, sometimes it’s necessary to do unscheduled inspections in the winter months, that can reveal issues that wouldn’t necessarily be noticed during warmer months.

Condensation, ice buildup and other moisture-related problems can all result when interior heat meets cold outdoor air, especially when temperatures drop below 0°C.

Industrial, commercial, and institutional (ICI) roofs behave differently in winter. As condensation forms, moisture sticks around longer, and problems suddenly crop up that normally wouldn’t occur in summer. Today we’ll explore some common cold-weather issues facility managers and property owners in the Greater Toronto Area should be looking out for. Because winter roof inspections and leak checks often tell a different story, it’s important to consider how cold weather conditions expose flat roof issues, and why condensation is often the real culprit.

Limitations of Roof Inspections During Winter

First, though, it’s important to point out that we don’t typically schedule preventative roof maintenance inspections in winter. There are many reasons for this, whether due to snow cover that prevents us from seeing the true condition of the membrane, or the colder temperatures that harden the roof surface and make it more challenging to detect soft insulation underfoot. But if we’re up on the roof, checking for suspected leaks or performing a due diligence inspection, we will certainly conduct an assessment to the best of our ability. 

Why Winter Roof Inspections Reveal Problems Other Seasons Miss

Condensation is one of the most frequently overlooked issues affecting flat roofs in the winter months. Many issues go unnoticed in summer, while winter conditions create the perfect storm of condensation, moisture buildup, and roof deficiencies.

That’s because, on industrial, residential and commercial flat roofs, moisture, air movement, and drainage present much differently in cold weather.

Here’s a look at some of the main ways winter conditions can affect flat roof inspections:

• Reduced Evaporation: Shorter daylight hours and low temperatures mean evaporation slows down and water remains on the roof for longer periods of time. In summer, this water may never be noticed due to the faster rate of evaporation. In winter, that water tends to linger. It may not necessarily mean there’s a problem, but property owners may notice it and think there’s a problem.
• Seasonal Ponding Water: Same applies to ponding water. Roofs that appear dry in summer may reveal ponding if they are under ice or after a winter rainfall or snow melt – even if the drainage system is the same.
• Condensation Formation: When warm, humid interior air meets cold outdoor air, it condenses at penetrations, steel components, flashings, and HVAC units.
• Ice Buildup: Moisture can freeze around drains, equipment curbs, and HVAC units – creating conditions that wouldn’t exist in warmer months.
• High Snow Piles: Snow drift and buildup against parapet walls, elevation changes, or roof projections can increase load, trap moisture, and interfere with drainage. These conditions are not a factor during spring or fall inspections, but they can hamper the ability to positively identify a roofing issue.

 

 

Importance of Documenting Weather Conditions

It’s important to remember that flat roof inspections only capture a snapshot in time. A fall inspection may provide a snapshot of a roof that may look much different in winter after even just a few weeks. For example, in summer, minor moisture or drainage issues may not be visible; in winter, these issues may present themselves thanks to slower drying times and freezing temperatures.

Here at Elite Roofing, we always take note of local weather conditions when inspecting a flat roof. Case in point:

• In summer, it’s common for water to evaporate before it can be documented, meaning the inspection would not reveal any ponding water issues.
• In winter, that same water could stay on the roof for days, raising concerns that weren’t apparent – or documented — during earlier inspections.

That’s why everything from temperature and recent rainfall should be noted, not only for one-time accurate reporting but for yearly comparisons as well.

 

Condensation Issues and Other Winter Flat Roof Challenges

Everything from condensation to ice buildup is common in winter, posing issues that would otherwise not be noticed in warmer months. Here’s a look at the most common issues:

• Condensation: When warm interior air meets cold outdoor air, water vapor buildup occurs – particularly at penetrations, HVAC units, steel posts, and flashing. In many cases, high indoor humidity can contribute to this (e.g., printing facilities that use misting systems to ensure paper doesn’t get stuck).
• Ice Buildup: Ice typically builds up around HVAC units and other penetrations, again caused by humidity from inside the building hitting cold outdoor air.
• Flashings and Insulation: Winter roof performance can be dictated by insulated vs. non-insulated flashings. Non-insulated or poorly sealed flashings are at a higher risk of forming condensation and ice buildup, especially around penetrations.

 

Effective Winter Roof Inspections

If a winter roof inspection is unavoidable, it will sometimes require a deferral until weather conditions improve to perform the most accurate assessment possible, especially in the face of cold weather, reduced daylight, and seasonal moisture conditions.

Elite Roofing uses a detailed standard checklist for every inspection. In winter, our roofers will check:

• Penetrations around HVAC units, steel posts, and flashing.
• Insulation levels to ensure proper flashing and sealing around penetrations.
• Areas of ice buildup, particularly near HVAC and steel posts.
• Proper drainage around HVAC units to prevent water pooling and freezing.
• Abandoned equipment and deferred maintenance issues, such as missing access panels, HVAC issues, broken windows, and metal corrosion. (While we don’t fix these issues directly, we will notify the client of these issues as a courtesy).
• Environmental factors, noting temperature, humidity, and recent weather conditions.

 

 

Common Maintenance Mistakes in Winter Roof Inspections

There are many mistakes property owners make when assuming they can inspect their own roofs.

First of all, many maintenance teams simply skip winter inspections altogether, or don’t consider weather-specific issues such as condensation and ice buildup.

Another common mistake – no matter the season – is for maintenance teams to fix problems without professional input, which can then lead to misdiagnoses or inadequate solutions. For example, some property managers mistake “blueberries” (small asphalt pebbles on the roof) as a serious issue when in fact these are harmless.

And finally, property managers and landlords often fail to distinguish between minor and major issues, and varying levels of concern between the two. What may look minor on the surface could be indicative of a much deeper issue, something that only a roofer would be able to determine with certainty.

This is why it’s so important to have comprehensive professional flat roof inspections at least once or twice a year, or more frequently if chronic concerns are raised. It’s also a good idea for transitioning tenants to schedule move-out inspections to ensure roofs are restored to prior condition before leaving.

Repairs specific to winter conditions can also help with peace of mind, such as using foam to seal steel posts and prevent condensation-related issues. It’s also wise to repair HVAC systems to ensure efficient operation while preventing excess indoor humidity.

 

Prevent Condensation and Ice Damage With Expert Insight

When called for, winter roof inspections can identify issues that may go unnoticed in warmer months, from condensation and ice buildup to moisture-related damage around penetrations. There are some issues that should never be ignored, even if they crop up in winter. For example, a delay in reporting leaks till spring can result in an inaccurate diagnosis, as the source of the issue may present differently when conditions change.

As your trusted professional roofing contractors in the Greater Toronto Area, we can effectively and safely address these winter-specific challenges to prevent costly repairs and extend the life of your flat roof. 

Rest assured, Elite Roofing brings decades of experience, thorough inspection checklists, advanced inspection tools, and a thorough understanding of cold-weather roofing issues. That’s the Elite Advantage!

 

Book a Roof Inspection with Elite Roofing Today

Give us a call for expert flat roof inspections and maintenance tailored to cold-weather conditions in the Greater Toronto Area. It’s also never too early to schedule your spring roof inspection to check conditions after the harsh weather of winter fades.