Sealed units
Foggy Window & Seal Repair
Haze trapped between two panes. It will not clear and it cannot be cleaned — and in Montana there are two reasons it happens that most of the country does not have to think about.
- What failed
- The sealed unit
- What stays
- Frame, sash and hardware
- Altitude
- Factored into the order
- Defogging
- Not offered
The drive is the job
Count them all before we drive out
Sealed units are made to size, so this is a two-visit job wherever you live: once to measure, once to fit. In Montana that means two long drives, which is exactly why doing them one at a time is such an expensive way to go about it.
Units on the same elevation age together under the same sun, so they tend to fail together. People notice one and discover four. Walking the house on a bright day with the light behind you, before you ring, is worth real money.
We would far rather measure six on one trip and fit six on the next than make twelve journeys over three years. The glass costs what it costs; the driving is the part you can avoid paying for twice.
On the truck
What rides on the truck for sealed units
The glass is ordered, but everything around it travels with us.
| What we carry | Why it is on board |
|---|---|
| Setting blocks and shims | A unit should sit on blocks, not on the frame. It is invisible when finished and it is the difference between a unit that lasts and one that does not. |
| Glazing beads and stops | In common profiles, because the originals are frequently brittle by the time they come out. |
| Neutral-cure sealant | The right chemistry for sealed units. The wrong sealant attacks the perimeter seal of the new unit you just paid for. |
| Timber repair materials | Because if the beads had failed, the rebate underneath has been wet, and bedding new glass onto damp wood is why some replacements fail early. |
| Measuring and glass-handling kit | Suction lifters and gauges, so the measurement is right the first time and the unit goes in without being dropped. |
| Capillary tube knowledge, not stock | Units destined for high elevation may be ordered with breather tubes. That is specified at order, not fitted on site, and we raise it before anything is made. |
Make the trip count
Make the measuring trip count
Everything on this list is free and all of it reduces the number of journeys.
Walk the house on a bright day
Light behind you, looking at each window square on. This finds the ones you have stopped noticing.
Check whether the haze wipes off
If it comes off either surface, the unit is intact and you have condensation or dirt. That one test rules out a good share of calls.
Look for a storm window
If there is one, the moisture may be in the gap between it and the sash rather than inside a sealed unit. Different problem, much cheaper.
Note which elevation each one is on
South and west almost always fail first. It tells us what to expect and helps us price the batch sensibly.
Tell us your elevation
Genuinely useful. Where you sit matters for how a unit is specified, and it is better raised before the glass is ordered than afterwards.
What Montana does to it
Why sealed units fail in Montana
Two of these five are close to unique to high, dry, wide-swinging country.
Altitude and pressure differential
A sealed unit is assembled and sealed at one elevation. Install it several thousand feet higher or lower and the trapped air is permanently trying to expand or contract. Across Montana's elevation range this is a genuine factor in unit life, and it is why capillary tubes exist for high-altitude glazing.
Chinook temperature swings
The state has recorded temperature changes of around a hundred degrees inside a day. A perimeter seal absorbs every bit of that movement. Nowhere else in the country asks quite that much of a bead of sealant.
Ultraviolet at elevation
Thinner air means stronger ultraviolet, and ultraviolet degrades the organic sealants holding a unit together. South and west elevations fail noticeably earlier than north ones here.
A very wide annual range
Hot dry summers and deep winters, every year, for as long as the unit lasts. That cycling is the ordinary mechanical cause of most failures well inside the life the glass was sold with.
Hail, months earlier
The delayed cause. A strike can shock a perimeter seal without cracking the pane, and the fogging appears a season later with no obvious connection to the storm.
By building
The buildings we work in
Where sealed units turn up, and what is different about each.
Log and timber homes
Log walls settle vertically for years after they go up, and the windows and doors in them need slip space above the frame to allow for it. Where that space was never left, or has been filled with trim and foam over the years, the opening slowly crushes the unit. A door that will not latch in a log home is often the building moving, not the hardware failing.
Ranch and outbuildings
Shops, barns, bunkhouses and equipment buildings with hardware that has to work in weather and gets no attention until it stops. Usually simple assemblies, usually repairable, and usually a long way from anybody who would come out for them.
In-town housing
Billings, Missoula, Butte, Helena and Great Falls hold a great deal of early-century stock — weight-and-pulley sash, putty glazing and original storm windows — plus post-war and modern suburbs where balances and sealed units fail together.
Manufactured homes
Common across rural Montana. Lightweight aluminium or vinyl frames, out-swing doors and sizes that match nothing in a store. We have a separate page for these because the parts and the advice are genuinely different.
Questions
Fogging questions
Will a foggy window clear up on its own?
No. The seal has failed and 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.
Does altitude really matter?
Yes, more than most people expect. A unit sealed near sea level and installed at five thousand feet is under permanent internal pressure. It is worth specifying properly at the point of order.
Could hail have caused this?
Very possibly, even if the pane never cracked. If fogging appeared across one elevation some months after a storm, that is the likely story.
Several have gone at once.
Normal, and the cheapest time to deal with them. Units on the same elevation age together, and batching them saves two long drives.
Coverage
Foggy window and seal repair across Montana
A mobile service covering the whole state. Pick your town below, or call and we will plan a route to you.
Foggy Window & Seal Repair Across Montana
Related
Other repairs we handle
Windows and doors are the whole business, so whatever has failed, it is on this list — and it can go on the same visit.
Next step
Count them, then call once
Free estimates across Montana, with the whole batch measured in one trip.