How Iowa's Freeze-Thaw Cycles Damage Your Windows (And What to Do About It)
If you've lived in Des Moines for more than one winter, you know the drill: 15 degrees on Monday, 45 degrees by Wednesday, then back below freezing by the weekend. This temperature rollercoaster isn't just hard on your mood—it's silently damaging your windows.
Central Iowa experiences anywhere from 50 to 80 freeze-thaw cycles in a typical winter. Each cycle stresses your window seals, frames, and glass in ways that add up over time. The result? Drafty windows, foggy panes, and repair bills that could have been avoided.
In this guide, we'll explain exactly how freeze-thaw cycles damage your windows, what warning signs to watch for, and how regular maintenance can protect your investment.
What Is a Freeze-Thaw Cycle?
A freeze-thaw cycle occurs whenever the temperature drops below 32°F and then rises back above freezing. In Des Moines, this can happen multiple times in a single week during winter—and sometimes within a single day.
Unlike cities with consistently cold winters (think Minneapolis, where temperatures stay below freezing for weeks at a time), the Des Moines metro sits in a transition zone where warm air from the south regularly collides with Arctic air from the north. This past winter alone, we saw temperatures swing from -13°F to the mid-40s within days.
For your windows, each cycle is like a tiny stress test. Materials expand when warm, contract when cold. Do this dozens of times over a few months, and the cumulative effect takes a toll.
How Freeze-Thaw Damages Your Windows
Seal Deterioration
The weatherstripping and seals around your windows are your first line of defense against the elements. These rubber and silicone components are designed to flex, but they have limits.
Every time temperatures swing, your seals expand and contract slightly. Over years of Iowa winters, this repeated movement causes the material to:
- Crack and become brittle
- Pull away from the frame
- Lose its ability to create an airtight barrier
Once seals start failing, you'll notice drafts even when windows are fully closed. If you have double-pane windows, damaged seals allow moisture to seep between the panes—that's when you get the permanent foggy look that no amount of cleaning can fix.
Frame Warping
Your window frames take a beating during freeze-thaw cycles, though the severity depends on what they're made of.
Wood frames are most vulnerable. Wood absorbs moisture from rain, snow, and humidity. When temperatures drop, any moisture in the wood freezes and expands. When it thaws, the wood contracts. This cycle can cause warping, cracking, and eventually rot. Many older homes in neighborhoods like Beaverdale, Drake, and Sherman Hill have original wood windows that show decades of freeze-thaw stress.
Vinyl frames handle cycles better but aren't immune. Extreme cold makes vinyl brittle, and repeated flexing can cause hairline cracks at corners and joints.
Aluminum frames are the most resistant to freeze-thaw damage, though they conduct cold readily, which creates other issues like interior condensation.
Glass Stress
Glass might seem solid and unchanging, but it expands and contracts with temperature just like other materials. The edges of your window glass, held tightly by the frame, experience the most stress during temperature swings.
Over time, this can cause:
- Micro-cracks that aren't visible to the naked eye but weaken the glass
- Stress fractures that start at the edges and spread
- Failed seals where glass meets frame
Older single-pane windows and windows with existing chips or cracks are particularly vulnerable. What starts as a tiny nick from a stray pebble can spread into a major crack after a harsh winter.
Track and Hardware Damage
Window tracks—the channels your windows slide in—collect debris, dirt, and moisture throughout the year. When winter hits, any water in these tracks freezes, expanding and potentially bending or cracking the track itself.
Ice buildup in tracks also puts stress on your window hardware when you try to open or close stuck windows. We've seen homeowners in Waukee and West Des Moines accidentally break window cranks, locks, and lift mechanisms by forcing frozen windows.
Warning Signs Your Windows Have Winter Damage
Not all freeze-thaw damage is immediately obvious. Here's what to look for as we head into late winter:
Condensation between panes: If you see fog or moisture trapped between double-pane glass, your seal has failed. This won't go away on its own—the insulating gas between the panes has escaped and been replaced by humid air.
Drafts near closed windows: Hold your hand near the edges of a closed window on a cold day. If you feel cold air, your seals are compromised. You can also use a candle or incense—if the flame or smoke flickers near the window edge, air is getting through.
Difficulty opening or closing: Windows that were smooth last fall but now stick, jam, or won't lock properly may have frames that warped over winter.
Visible gaps: Look closely where the glass meets the frame, and where the frame meets the wall. Any visible daylight or gaps indicate seal failure.
Increased energy bills: If your heating costs spiked this winter without an obvious explanation, failing window seals could be the culprit. The Department of Energy estimates that heat loss through windows accounts for 25-30% of residential heating energy use.
How Professional Cleaning Prevents and Identifies Damage
Here's something most homeowners don't realize: professional window cleaning isn't just about aesthetics. It's a form of preventive maintenance.
When we clean your windows, we're also inspecting them. We see every window on your home up close—something most homeowners rarely do. We routinely spot:
- Early seal failures before they become obvious
- Debris buildup in tracks that could cause ice damage
- Small cracks or chips that should be repaired before winter
- Frame damage that needs attention
Regular track cleaning is particularly important for Iowa homes. Removing leaves, dirt, and debris from your window tracks before winter prevents water from pooling and freezing. Clean tracks also allow windows to operate smoothly, reducing stress on hardware.
Clean window seals also last longer. Dirt and grime break down rubber and silicone over time. Keeping seals clean helps them maintain their flexibility through freeze-thaw cycles.
Protecting Your Windows This Winter
While you can't control Iowa's weather, you can minimize freeze-thaw damage:
Keep tracks clear: Even a quick wipe-down of window tracks in late fall can prevent ice buildup. Remove any leaves or debris that collect there.
Address small issues quickly: A tiny crack or chip is inexpensive to repair now. After a winter of freeze-thaw cycles, it could be a major crack requiring full window replacement.
Maintain consistent indoor humidity: Very dry indoor air causes wood frames to shrink; very humid air causes swelling. Keeping humidity between 30-40% in winter reduces stress on frames.
Schedule a spring inspection: The best time to assess winter damage is March or April, before you need to start opening windows regularly. This gives you time to plan and budget for any repairs.
Get Ahead of Winter Damage
If you've noticed any warning signs—or if it's simply been a while since anyone took a close look at your windows—we're happy to help.
Every window cleaning service from Birdie includes a visual inspection at no extra charge. We'll let you know if we spot anything concerning so you can address small problems before they become expensive ones.
Serving Waukee, West Des Moines, Ankeny, Des Moines, and the entire Central Iowa metro, we're familiar with exactly what Iowa winters do to local homes.
Ready to schedule? Get a free quote or call us at (515) 518-0623. We typically respond with estimates within one business day.
Paul Miller founded Birdie Window Cleaning to bring reliable, professional service to Des Moines area homeowners. Based in Waukee, we serve Dallas County and Polk County with residential window cleaning, screen cleaning, and track cleaning services.
