Sealed units
Foggy Window & Seal Repair
Haze trapped between two panes. It will not clear, it cannot be cleaned, and in Missouri it is very often the delayed bill for a hailstorm you thought you got away with.
- What failed
- The sealed unit
- What stays
- Frame, sash and hardware
- Visits
- Measure, then fit
- Defogging
- Not offered
Don't take our word for it
Six things we say, and how to verify each one
Fogging is the most over-quoted fault in this trade. Every claim here is checkable from your own living room.
| What we say | How to check it yourself |
|---|---|
| It is the glass unit that failed, not the window | Open and close the window, then lock it. If it operates and locks normally, the sash, the hardware and the frame are all fine. Only the glass is not. |
| The haze is genuinely inside the glass | Wipe both surfaces with a dry cloth. If the haze is unaffected from inside and outside, it is in the sealed cavity and nothing you do to the surfaces will reach it. |
| Defogging does not restore anything | Ask anybody selling it one question: does it restore the gas fill and reseal the perimeter? The honest answer is no. It clears the view and leaves you with a window performing roughly like single glazing. |
| You do not need a whole new window | Look at how the glass is held in — snap-in beads, a stop, or putty. All three are removable, which means the unit inside is replaceable without touching the frame. |
| A hailstorm can cause this months later | Think back. If fogging appeared across one elevation some weeks after a storm, that is the pattern. The pane held, the seal did not, and the desiccant ran out afterwards. |
| Doing an elevation together is far cheaper per window | Count them on a bright day with the light behind you. Most of what you pay for one window is the visit, not the glass. |
Five minutes, no tools
Four tests to tell the lookalikes apart
Three of the four things that look like a fogged window are not one, and sorting them out costs nothing.
Test 01
Wipe it, inside and out
If the haze comes off either surface, the unit is intact. This alone resolves a surprising share of the calls we take.
Test 02
Check the outside on a humid morning
Water on the exterior of a cold pane in a Missouri July means the air conditioning has chilled the glass below the dew point. The glass is working. It is the opposite of a failure.
Test 03
Look for a storm window
If there is one, the moisture may be in the gap between the storm and the sash, not in a sealed unit. Blocked weep vents, cheaper fix, different job entirely.
Test 04
Walk the house at midday
Bright light behind you, looking at each window square on. People notice one and find four, almost always on the same side of the house.
On the day
What we demonstrate before we leave
Glass work is easy to verify if somebody bothers to show you.
The old unit out of the sash, so you can see the failed perimeter seal for yourself.
The glazing rebate dry and sound before the new unit goes in — or repaired first if it was not.
The new unit sitting on proper setting blocks rather than on the frame.
Drainage clear beneath the glass, checked with water before the beads go back.
The window operating and locking exactly as it did before, with nothing else disturbed.
In writing
What you get on paper
Four things on every estimate and every invoice, without being asked.
A named component
The estimate says which part failed — a cord, a balance, a keeper, a roller, a closer. Not 'window needs work'. If a quote will not name the part, it has not diagnosed anything.
A fixed price, before we start
Agreed in writing, and it does not move once we are working. If we think we might find rot or hidden damage, you get a price for both outcomes up front.
What we did not do, and why
Anything we looked at and left alone is listed, with the reason. That is how you know we checked it rather than missed it.
Paperwork an insurer can use
Itemised, dated and photographed where relevant, formatted to submit without anybody rewriting it.
Missouri conditions
Why sealed units fail in Missouri
Hail, a very wide annual range and a lot of ageing replacement glazing.
Hail is the hidden cause
This is the Missouri-specific part. A hailstorm can strike a pane hard enough to compromise the perimeter seal without cracking the glass. Nothing looks wrong at the time, and the window fogs weeks or months later — by which point nobody connects the two.
A hundred degrees of annual movement
From humid summer afternoons to hard winter nights, the panes, spacer and seal expand and contract every year. That cycling is the ordinary mechanical cause of most failures.
Solar load on south and west walls
Those elevations run hottest and fail first. If one side of the house has fogged and the others have not, that is why, and it is entirely normal.
A generation of replacement windows now failing
Missouri had an enormous wave of vinyl replacements fitted from the eighties onward. Those sealed units are reaching the end of their lives, and the glass is usually replaceable inside the frame.
Questions
Fogging questions
Will a foggy window clear up on its own?
No. The seal has failed and the moisture is permanently inside the cavity. It looks better on dry days, which is why people second-guess it.
Is defogging a real repair?
It improves the view and nothing else. It does not restore the seal or the gas fill, so we do not offer it.
Do I have to replace the whole window?
No. Only the sealed glass unit. The frame, sash, trim and hardware all stay exactly where they are.
Could hail have done this?
Very possibly. A strike can compromise a seal without breaking the pane, and the fogging shows up months later. If it appeared across one elevation after a storm, that is the likely story.
There is water on the outside of my glass.
Exterior condensation. Your air conditioning has chilled the pane below the dew point. The glass is doing its job.
How urgent is it?
Not very. It is a performance problem rather than a damage one, and it is reasonable to stage over a couple of years.
Coverage
Foggy window and seal repair across Missouri
A mobile service covering the whole state, both metros and the rural counties between them. Pick your town below, or call and we will come to you.
Foggy Window & Seal Repair Across Missouri
Related
Other repairs we handle
Windows and doors are the whole business, so whatever has failed, it is on this list.
Next step
Work out what you actually have
Free estimates across Missouri, and an honest answer about defogging.