Why Is There Condensation Between My Double-Glazed Windows?
If you’re noticing mist, fog or droplets forming inside your double-glazed windows, it’s a clear sign something’s not quite right. This type of condensation—trapped between the panes—isn’t something that can be wiped off. It usually points to a problem with the seal of your window unit.
Understanding the Basics of Double Glazing
Double-glazed windows are made with two panes of glass, sealed together with a gap in between. This gap is often filled with gas (like argon) to help with insulation. When everything is intact, the unit is airtight and helps keep your home warm and energy-efficient.
So What Causes Condensation Between the Panes?
Condensation between the glass happens when the seal around your double-glazed unit fails. Here are some reasons why that seal might break down:
- Age and wear: Over time, seals naturally deteriorate—especially if your windows are 10+ years old.
- Poor installation: If the window wasn’t sealed properly from the start, it may fail prematurely.
- Extreme weather: Heat and UV rays can cause seals to crack or harden, while cold can shrink them.
- Building movement: Homes expand, settle, and shift over the years, putting pressure on window frames and seals.
Does This Mean the Whole Window Needs Replacing?
Not usually. The good news is that misted glass doesn’t always mean your frames are faulty. In most cases, you can simply replace the glass unit inside the frame, without touching the window structure itself.
This is called a glass-only replacement, and it’s usually much cheaper and quicker than a full window replacement.
Repair vs Replacement: What’s Best?
Let’s be clear—once the seal has failed, the unit can’t be repaired in a reliable, long-lasting way. Some services may offer to drill holes and remove moisture, but these fixes are often temporary and don’t restore proper insulation.
Your best bet is usually a full replacement of the double-glazed unit (not the whole window). This restores your window’s energy efficiency and gets rid of that unsightly fog for good.
Can You Stop Condensation from Happening?
While you can’t completely prevent seal failure forever, there are steps that can help extend your windows’ life:
- Ventilate your home to balance indoor humidity
- Keep windows clean to avoid damage to seals
- Choose high-quality replacement units with energy ratings
If you’ve already got misted windows, best to fix them now before it leads to higher heating bills or further damage.
How Get My Windows Fixed Can Help
We specialise in replacing misted or blown glass units quickly and efficiently—often without needing to touch your frames. Our expert team can assess the issue and recommend the most cost-effective solution for your home.
There’s no call-out charge, and we’ll give you a clear quote upfront so you can decide what’s right for you.