Blown seals · Windsor-Essex
Fogged-up thermal glass? Swap the sealed unit, keep the frame
It's a sticky July morning in Windsor, Ontario, and the family-room window looks milky. Before you price a new window, wipe the glass on both sides. If the haze comes off, it's weather, and it'll likely be gone by lunch. If it's sealed between the panes, the unit has a blown seal. That's usually a glass job, not a window job. We connect you with an independent local glass pro who does this work and will call you back to quote it.
- Often just the glass, not the frame
- Defogging, new unit or new window, compared evenly
- Several units quoted together, per unit
Check it first
Seal failure or just a humid Windsor morning? A quick test
Windsor mornings are usually muggy, even when the afternoon dries out, so a lot of fog on glass here is plain weather. Take a dry cloth to both sides of the pane.
Fog you can wipe off, inside or out
Dew on the outside on a summer morning is normal: the outer pane of a good unit stays cool and damp air settles on it. Room-side fog comes from showers, cooking or a humid house. Either way the seal is fine. The humidity and condensation guide covers what helps.
Haze or droplets you can't reach, between the panes
If the moisture sits between the panes, no cloth will touch it. It may come and go with the sun, leave white streaks, or settle into a haze that never lifts. That's a blown seal, and it won't dry out by itself.
Local terms
Blown seal, thermal glass, sealed unit: one part, three names
Around here, people say “thermal glass” for what the trade calls a sealed unit: two panes with a spacer between them and a seal all the way round, the gap filled with dry air or gas. When that edge seal lets go, it's a blown seal, a broken seal or a seal failure. Same part, same fix.
Seals age. Sun, hot afternoons and cooler nights all work on them, long stretches of air conditioning can contribute, and water sitting in a frame that doesn't drain is hard on them too. The frame, cranks and locks are separate parts with their own fixes.
The usual fix
What replacing a sealed unit involves
The frame, sash, trim and hardware stay. Only the glass changes.
Photos, then an exact measure
A photo and a tight shot of one corner often give a pro enough for a first price. Then the unit is measured precisely.
A unit made to order
Units are built to order, so measuring and installing are separate visits. Choose the glass now: low-E, tinted, obscure, or tempered where required.
Set into the existing sash
The fogged unit is lifted out; the replacement is set, sealed and held with its stops. The window looks as it always did, minus the fog.
Several fogged units? One request
List them all at once. A per-unit quote for the batch lets you do the worst now and the rest later, with prices already known.
Options, side by side
Defogging, a new unit or a new window
You'll hear three answers to a foggy window around Windsor-Essex. Each suits a different situation.
Professional defogging
Small holes are drilled, the cavity is washed and dried, then the holes are sealed. It can improve the look of a unit whose glass hasn't etched. It doesn't restore the original seal or gas fill, so ask what the provider stands behind.
A new sealed unit
A replacement unit built to the opening goes into the same frame. It brings back a factory seal and lets you choose a better coating. It suits a solid frame and usually sits in the middle on price.
A new window
Frame, sash and glass all replaced: the biggest job, and the only one that can count toward the provincial rebate. It suits a window failing in more ways than the glass. The repair-or-replace guide weighs the two.
Beyond the glass
When a new glass unit isn't enough
A unit is only as good as the frame around it. Watch for soft wood at the sill or bottom rail, a frame that's warped or pulling from the wall, and the same opening fogging again after a replacement, which often means water is pooling in the frame.
In those cases, price a replacement window next to the glass. The pro should tell you which way they'd lean, and why.
What affects the quote
What a sealed-unit quote depends on
No two units are quite alike, so the details set the price:
- Size and shape, from a tall picture unit to an arched top
- Glass type: low-E, tinted, obscure or triple pane
- Tempered glass, needed in doors and some other openings
- Access, such as an upstairs window or one behind a deck railing
- Frame condition, and whether the sash must be removed
- How many units, since a batch is quoted per unit
A photo, a tight shot of a corner and rough measurements usually get you a first quote without a visit.
Hot, sunny rooms
Glass choices for hot, sunny exposures
West- and south-facing rooms here take long, hot afternoons, so a new unit is a chance to ask about low-E coatings made for solar control, and gas fill. Judge them on rated specs, not adjectives; for complete windows, the ENERGY STAR label uses one national standard in Canada. According to Natural Resources Canada, low-E coatings and insulated frames also mean less condensation on the glass.
Rebates and grants
Rebates: what a new sealed unit does and doesn't qualify for
Ontario's Home Renovation Savings Program pays per opening for complete ENERGY STAR windows and doors, usually as part of a home energy assessment. A new unit in your old frame doesn't qualify. Check the program page for current rules.
That doesn't make it the wrong spend. When the frame is sound and one or two units have blown, new glass can still be the smaller bill after a rebate is counted. In Sandwich and Ford City, the City's neighbourhood improvement grants name window repair as well as replacement; the grants guide explains who qualifies.
Around Windsor-Essex
Where fogged units show up most in Windsor-Essex
Much of Tecumseh and a good share of LaSalle went up between the early eighties and 2000, and the original thermal glass in those subdivisions is now failing one window at a time.
Patio doors have sealed units as well. If the fixed panel of a slider has gone cloudy, see door glass replacement.
Questions
Blown seal and thermal glass questions
Explore your options
More help with foggy glass
Local pros replace sealed units right across Windsor-Essex, including Tecumseh, LaSalle, Forest Glade and Belle River and Lakeshore.
Photograph the fogged unit and the frame corner
Add a tight shot of one corner and rough measurements. We'll send it to a glass pro near you who swaps sealed units, and they'll call you back with a quote.