What’s Your Window Saying About Your Home?
Maintenance tips for tough Janesville winters—plus when it’s time to call City Glass
In Janesville, winter doesn’t “test” your windows—it interrogates them. If your glass is fogging, frames are sweating, drafts are creeping in, or you’re fighting ice buildup, your windows are telling you something: comfort and efficiency are leaking out.
This guide breaks down practical winter window maintenance you can do now, the red flags that mean repairs won’t cut it, and when a full replacement makes more financial sense. If you need a professional diagnosis or want a quote, City Glass Company specializes in residential window installation and repair across Southern Wisconsin and Northern Illinois.
Drafts: the “invisible” problem that costs the most
If you feel cold air near a window—even if it’s closed—winter energy loss is already happening.
What to do:
- Check for gaps where trim meets drywall or casing meets frame.
- Replace worn weatherstripping and cracked caulk (common around older units).
- Verify the sash actually locks tight—loose locks can create air gaps.
If drafts persist after basic sealing, the issue is often deeper (frame warping, failed seals, poor fit). That’s where an expert inspection helps. City Glass handles window repair and replacement, not just “swap the glass and hope.”
Explore their window service page here:
Residential Windows: Installation & Repair
Foggy glass: when condensation means more than humidity
Condensation can be normal on very cold days—but fogging between panes is a different story. That usually indicates a failed insulated glass seal, which reduces efficiency and visibility.
Quick diagnostic:
- Inside surface fog: often indoor humidity / airflow issue.
- Between panes fog: likely seal failure.
If you’re seeing between-pane fogging, it’s time to talk repair vs. replacement options with a pro. City Glass’ residential window services are designed for exactly these scenarios.
“Sweating” frames and sills: watch for moisture damage
If the bottom of the window or sill feels damp, you’re risking:
- peeling paint and wood rot
- mold growth in trim/drywall
- ice buildup and sticking sashes
What helps immediately:
- Keep blinds slightly open on the coldest nights to reduce trapped moisture.
- Run exhaust fans during showers/cooking.
- Maintain healthy indoor humidity (many winter issues are amplified by overly high humidity).
If you’re noticing recurring moisture, it’s worth evaluating whether the window is underperforming or improperly sealed.
Sticking windows: the winter sign of alignment and hardware issues
Cold weather can magnify minor mechanical problems:
- sashes that don’t track smoothly
- swollen wood frames (older windows)
- worn balances, rollers, or latches
Don’t force it. Forcing a stuck window can crack glass or damage hardware—then you’re paying for the original problem plus a break.
If your windows are hard to open, don’t stay shut, or won’t lock properly, a repair evaluation is the next step. Start with City Glass’ window services here:
Residential Window Repair & Installation
Ice at the bottom of the window: stop it before it spreads
Ice often forms because warm air leaks out and meets freezing surfaces—then melts/refreezes.
Prevention steps:
- Seal obvious air gaps (interior trim edges are common offenders).
- Make sure exterior drainage/weep paths aren’t clogged.
- Confirm the bottom seal and exterior caulk line are intact.
If the ice keeps returning, the window assembly may be leaking air or water and should be professionally evaluated.
When it’s time to replace instead of repair
Here’s the honest line: some windows are past the point where maintenance makes sense.
Replacement is usually the smarter move when you have:
- multiple windows with failed seals (between-pane fogging)
- persistent drafts after sealing efforts
- damaged frames, rot, or recurring moisture intrusion
- rising heating bills paired with cold rooms
City Glass emphasizes residential window installation and works with homeowners across the region to select functional, attractive upgrades—not just “whatever’s cheapest.”
Don’t forget the “whole opening”: doors and patio doors matter too
In many homes, the biggest winter leak isn’t a window—it’s a patio door that doesn’t seal tight.
City Glass also provides residential door and patio door installation for improved security and energy efficiency. If your sliding door feels like a cold wall in January, put it on the same inspection list as your windows.
