Foggy Windows Explained and What To Do

Foggy Windows

You wake up one morning and pull your drapes only to see cloudiness, making it impossible to see your beautiful view or maybe just your neighbors house for the most of us. You most likely have what we call a “failed seal.” 

Legit Cloudy Window

What is a failed seal and why does it happen?

A failed seal is exactly what it sounds like. The urethane sealant used around the perimeter of a double pane insulated glass unit (IGU) or triple pane glass unit has deteriorated to the point of causing a air/moisture leak into the inside of the sealed unit. Of course it’s important to note that a failed seal is not even a possibility when you have single pane windows since there is no IGU involved. When a failed seal happens, the glass normally becomes increasingly cloudy as time goes on. A failed seal occurs overtime due to the sun exposure and wind exposure. That is why it’s more common to see windows on the bad weather side of the house to fail first. It can also be caused by poorly caring for the window (slamming it shut) or by inferior manufacturing.

Make sure it is indeed in between the panes of glass 

I can’t tell you how many times people say that they have a failed seal when in reality it is just surface condensation. Surface condensation can form on the very exterior pane on the outside of the window (surface #1) and/or on the very interior side of the inside pane (surface #4). Humidity levels, glass types, frame material, indoor/exterior temperatures, blinds up or down, as well as air flow can all be contributing factors into surface condensation. The fine details of that phenomenon is for a later post. Back to my main point, be sure to physically wipe both sides of the glass to ensure it is not just surface condensation. After you’ve checked that and condensation or cloudiness remains then a failed seal is in order.

What to do with a failed seal

FIRST check to see if it’s under warranty. Some window manufactures have a lifetime warranty for the original homeowner. Look for a logo marking on the locking mechanism, etched into the corner of the glass or on a sticker. Some manufactures also carry a 10 year or 20 year transferrable warranty from when the windows were manufactured.

Simply high humidity levels condensing on the glass as it tries to escape the house

If they are not covered under warranty then you will need to pay for replacement glass. Most windows can have just the IGU’s swapped out within their existing frames. A huge benefit to this is that it’s low cost as well as very non-invasive on your home. Beware of the companies who claim to “suck the moisture out of the sealed glass.” It may work for a short period but long term it’s not a good solution and you’ll have wasted your money. 

If your windows are higher quality wood or wood/clad (wood interior with a fiberglass, vinyl or aluminum exterior) windows then replacing the glass only probably wont be feasible. You’ll most likely need to replace the entire “sash.” The sash is simply the frame that directly surrounds the glass and typically includes the glass itself. 

Most glass or window companies will opt to replace the entire sash due to the difficulty of “freeing” the glass out of the frame without damaging the wood or cladding. Additionally, sealing back up the new glass in the existing frame to the original window manufactures specifications is darn near impossible. Therefore, if you have a wood/clad window expect this outcome. A full sash will be more expensive than just glass but hey, you have nice windows so do you expect? The last thing I should mention is that in order to replace the entire sash, YOU WILL NEED TO KNOW THE MANUFACTURE. If no one can identify the brand (or the brand is out of business) then you will have to buy a whole new window… unless you’re able to find a glazier willing to take on the challenge and responsibility.

Should I consider full window replacements?

When to consider replacing the entire window frames versus just the glass is a loaded question but I’ll do my best to navigate it. 

First thing I always ask people is; how long do you want/plan to live in the house? If the answer is “one more year” then entire new windows are usually not the best ROI. If it’s a 5-10 year home or better yet a forever home than replacing the entire windows may be worth it. 

Secondly, we must consider what kind of windows you have now. If they are old sweaty aluminum windows from the 70’s and half of the windows in the house have failed seals, it’s time for new windows (not just glass). On the flip side, if you have a house built in 2005, then replacing the glass only with more efficient glass may be the smarter choice. 

It really comes down to, what’s your budget, how long do you plan on living in this house, how efficient do you want the windows to be. If you can answer those questions for yourself, you’ll know what to do most of the time with a professionals input and cost analysis. Just remember that replacing the entire window PROPERLY entails replacing exterior trim (or cutting back the siding if no exterior trim exists) and sometimes replacing the interior trim as well depending on goals and window type. Vinyl, fiberglass and composite windows don’t require replacing the interior trim, usually just altering it slightly to accommodate the new window depth. Whereas, wood/clad products come with the jamb (interior liners/trim) attached to the frame. Consequently often times requiring blinds to be cut down or replaced.

New black/black window installed into existing rough opening

Ultimately 

A failed seal means there is a breach within the sealed IGU and you have two choices. Replace the glass (or sash for wood/clad products) or replace the entire window frame. Make sure to do your research and get multiple quotes/opinions before deciding what to do.