Yes, in most cases. It usually means replacing the damaged sealed glass unit inside your frame. The project rarely calls for a brand new window.
Misty windows are frustrating. You wipe the glass, but the fog stays put. That usually means the moisture is trapped between the two panes.
This guide explains what causes the problem, how to check your windows and which fix makes sense for your home.
What Causes Condensation Between Double Glazing?
Double glazing is made of two panes of glass with a sealed gap between them. That gap is often filled with an insulating gas. A seal around the edge keeps damp air out. When that seal fails, moist air gets into the gap. Then, as the glass cools, the moisture condenses on the inside of the panes. As a result, you see fog that no amount of wiping will clear.
Common reasons a seal fails include:
- Age: seals slowly break down over the years
- Temperature swings: strong sun and cold nights put constant stress on the unit, especially on south facing windows
- Poor drainage: water sitting in a frame with blocked drainage holes can damage the seal
- Installation problems or damage: a unit that was fitted badly or knocked can fail early
In short, condensation between the panes is a sign of a failed seal. It’s not a cleaning problem.
Is Your Double Glazing Actually Blown?
Not necessarily. Before you book a repair, check where the moisture sits. This can be done by a quick wipe test:
- Wipe the inside of the glass. If it clears, it’s ordinary condensation from humid indoor air.
- Wipe the outside. If it clears, it’s outdoor condensation. This is often normal on cool mornings.
- If neither side clears, the moisture is between the panes. Your sealed unit has failed.
If the condensation is on the room side, the cause is usually humidity in your home rather than your windows.
Our guide to damp, condensation or water leaks explains how to tell these problems apart.
How to Fix Misted Double Glazing
There are three main ways to deal with misted glass. The right one depends on the condition of your frame.
Replace the Misted Double Glazing Units
This is the most common fix. A glazier removes the glazing beads, lifts out the failed unit and fits a new one made to the same size. Then the beads go back on. Your frame, hinges and handles all stay in place.
Because you keep the frame, this is usually much cheaper than a full window replacement. It also restores a clear view and brings back the insulating performance of the glass. In many cases, the new unit can match your existing glass, such as obscure glass in a bathroom.
Demisting Services
Some companies offer to demist the unit instead. Typically, they drill small holes in the glass, dry
There’s no single price for misted double glazing repair. Instead, the cost depends on a few key factors:
- Window size: larger sealed units cost more than small ones
- Glass type: toughened, obscure, acoustic or decorative glass usually costs more than standard clear glass
- Number of units: fixing several windows in one visit may make each one better value
- Access: upstairs or awkward windows can add time to the job
- Frame condition: any frame repairs will add to the total
Before you pay for anything, check your warranty. If your windows were fitted in recent years, the sealed units may still be covered. So dig out your paperwork first.
After that, the simplest way to find the real cost is to compare quotes. You can post your job for free and hear from local glaziers.
Hiring a Glazier for Double Glazing Repair
Misted units are one of the most common double glazing repair jobs. Still, it pays to choose the right person. Whether you have one misted pane or need wider window glazing repair, ask these questions before you book:
- Will you replace the sealed unit or demist it?
What guarantee comes with the new unit?out the gap and then seal the holes.
This can improve how the window looks. However, it usually can’t restore the unit’s original airtight seal or insulating performance. So the misting may come back, and the glass may not keep your home as warm as a new unit would.
Replace the Whole Window
You only need a new window if the frame itself has failed. Look out for rot, warping, cracks or hinges that no longer close the window properly. In that case, a new sealed unit won’t solve the bigger problem.
If you’re weighing up new windows, see our guide on how much it costs to fit windows.
What Affects Misted Windows Repair Cost?
- What glass will you use, and will it match my other windows?
- How long will the job take?
- Is my frame sound, or does it need work too?
A good glazier will answer clearly and put the quote in writing. For more tips, read how to find reliable window fitters near you and how to find a good local window fitter.
Get Your Misted Windows Sorted
Misted double glazing won’t fix itself, but the repair is usually simple. In most homes, a new sealed unit brings back a clear view without the cost of new windows.
Ready to sort it? Post a job for free and compare quotes from local glaziers. You can also browse the directory or explore all services on The Trade Core.
Are you a glazier? Join as a tradesperson and connect with homeowners who need your skills.
Frequently Asked Questions
Can misted double glazing clear on its own?
The fog may come and go with the weather, but it won’t disappear for good. Once moisture is inside the sealed unit, the seal has failed. Only a repair or a new unit will fix it.
Does misted double glazing lose heat?
It can. A failed seal can let the insulating gas escape and moisture get in. As a result, the unit may not insulate as well as it did when new.
Can you replace just one pane of glass?
Usually not. Double glazing is made as one sealed unit, so a glazier replaces the whole unit rather than a single pane.
Is it worth repairing misted double glazing?
In most cases, yes. Replacing a failed unit restores your view, improves insulation and helps your existing frame last longer.