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Fogged IGU: replace the glass or the whole window?
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One of my insulated-glass units has failed: there’s moisture and fogging between the panes, but the frame and sash still look straight and operate normally.
I’m trying to compare replacing only the IGU with replacing the entire window. For quotes, what should I ask to see separately?
- IGU cost and replacement-glass specifications
- Labor for removing and reinstalling the sash or glass
- Any glazing, stops, seals, or hardware that would need replacement
- Total cost for a complete replacement window, including installation and trim
If the frame isn’t warped, rotted, or leaking, is there usually a good reason to replace the whole window? Also, is IGU-only replacement realistic as a DIY job on some window types, or does it usually require a glass shop? I’m wondering whether a new IGU will match the existing sash and whether the warranty covers the seal.
1 reply
Before comparing prices, have the quote identify the replacement IGU’s exact specifications. The thickness and edge dimensions need to match the sash, and spacer type, low-E coating, and gas fill can affect both fit and performance. A mismatch may lead to clearance problems, a different appearance, or more condensation than expected.
A glass shop can often measure and replace the unit without replacing the whole window, especially when the sash is sound. I’d also ask whether the seal warranty covers only the glass unit or includes labor, and whether the installer will replace damaged glazing stops or seals found during removal.
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