Broward County Certificate of Competency 20-WD-21968-X
Why are my impact windows fogging up between the glass panes?
A straight answer for Broward County homeowners, then what you can check yourself and when to call. Free estimate: (954) 906-1715.
Fog or haze between the panes means the sealed edge of the insulated glass unit has failed, so humid air and moisture have gotten into the air space. Once that seal is broken, the moisture cannot be wiped away, and the unit usually has to be replaced rather than cleaned.
The nuance is where the fog sits. Fog on the inside or outside face of the glass is ordinary condensation and wipes off. Fog trapped between the layers is a seal failure. Cloudiness or bubbling at the edges that looks like part of the glass itself can be a separate problem with the laminated layer, which a pro should look at.
Why it happens
An impact window is a sealed unit: laminated glass, an air space and a perimeter seal, held in a frame. A drying agent inside the unit keeps the air space clear. When the perimeter seal degrades, humid air slips in and the drying agent eventually can't absorb any more. The moisture then condenses on the glass surfaces you can't reach.
South Florida conditions are hard on those seals. Intense UV and heat, daily temperature swings, year-round humidity and wind-driven rain all work on the sealant. Salt air near the coast can also corrode older aluminum frames and hardware. Water that sits in a frame because of clogged drainage, failed exterior caulk or a poor installation can also attack the seal from outside.
Sometimes it is a manufacturing or installation issue and sometimes simply age. That is why it helps to note when the windows went in and whether the fogging is spreading to other windows.
What you can check yourself
Do the wipe test
Wipe the inside face, then the outside face. If the fog doesn't move, it is between the panes and the seal has failed.
Look at the pattern
Droplets, a milky haze or mineral-looking streaks that start at the edges point to a seal failure. Note whether it comes and goes with the weather or stays.
Check the frame and caulk
Look for cracked or missing exterior sealant, staining below the window, and weep holes or tracks packed with debris. Standing water around a frame can shorten the life of the glass seal.
Count the affected windows
Is it one window or several, and are they on the same side of the house? A cluster on a sun-facing wall suggests age or heat exposure. A scattered pattern is more likely a product or installation issue.
Photograph and gather paperwork
Take photos, and find the install date, the product label or the approval documents. Contact the manufacturer or whoever installed the windows to ask what they cover for seal failure.
When to call a pro
Call if the fog is between the panes, if it is spreading, or if you see water staining, soft trim, a cracked pane, corrosion on the frame, or a window that no longer closes and locks properly. Those signs suggest the problem goes beyond the glass seal. Don't drill, inject or pry at impact glass yourself.
Replacing a window or its glass in Broward is permitted work, and it should be done by a properly licensed contractor. Our Broward County Certificate of Competency for windows, doors, shutters and garage doors is 20-WD-21968-X. You can verify any contractor's category and standing with the Broward County Central Examining Boards and DBPR. Whether a glass-only swap needs its own permit can vary, so verify with your city's building department. Condo and HOA owners usually need association approval too.
Impact Windows work is done under Broward County Certificate of Competency 20-WD-21968-X (windows, doors, shutters & garage doors).
What a pro will do
- Diagnose the real causeWe confirm it is a failed seal rather than surface condensation or a laminate issue. We also check the frame, sealant and drainage for water entry.
- Check the product approvalImpact windows in the High-Velocity Hurricane Zone need an approval for the HVHZ, usually a Miami-Dade NOA. Any replacement glass or window must match an approved assembly, not just fit the opening.
- Replace the unit or the windowDepending on the product and the frame's condition, that means a new glass unit or a full window measured to the opening. The window is installed and anchored to its approval.
- Handle permits and inspectionsWhen the work needs a permit, we pull it, schedule inspections and get the permit closed out.
Related questions
- Is a fogged impact window still protecting my home?
- The seal mainly affects clarity and insulation, but the window's protection also depends on the laminated glass, the frame and the anchoring being intact. Have a pro confirm the whole assembly, especially if there is a crack, corrosion or a leak.
- Can fogged glass be defogged without replacing it?
- Some services drill into the unit to vent it, but that does not restore the seal, and altering an impact-rated assembly is a poor idea. Replacement with an approved product is the dependable fix.
- Will a fogged window affect my wind-mitigation form?
- Opening protection is one category on form OIR-B1-1802, which a licensed inspector completes. Florida law (s. 627.0629, Florida Statutes) requires insurers to offer discounts for wind-loss-mitigation features. Our free Wind Mitigation Credit Checker can help you see where your home stands.
- Do I need a permit to replace just the glass?
- Permits are required for window replacement, but glass-only repairs can be handled differently. Verify with your city's building department before work starts.
- How do I get an estimate?
- Call us at (954) 906-1715 or use the quote form on this page. The estimate is free, and we serve Broward County only.
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