Home ownership is full of little gotchas that they don't tell your about, but should. Here's an unpopular opinion: avoid windows with low-e coatings.
Window manufacturers love low-e coatings. Why? In part, because they give them an extra selling point, some minor energy savings that fill out another bullet point in their sales brochure. Also, it means they can sell you that same window again within a decade.
Why? You see, the seals in windows are only airtight for seven years or so. After that, they can start to leak, and you might ordinarily get a little condensation inside from time-to-time depending on its location, but not much more serious than that.
Unless, of course, you have a low-e coating. Then, any moisture that gets inside can oxidize the coating, leaving the window permanently damaged, requiring immediate repair or replacement. And then, good luck finding the former as everyone we contacted only wanted to do the latter.
For a long time, we didn't know what to do, and endured living in a house with a half-dozen failing vinyl windows. Eventually, however we figured out a bit about how our windows are constructed. Underneath some removable vinyl trim trim strips, a double-paned sealed-glass unit (two sheets of glass around a border spacer piece also known as an SGu) are simply adhered to the window with special double-sided foam tape (glazing tape). The whole window didn't need to be replaced, just the SGU.
Fortunately, we found a company online (onedayglass.com) that sells sealed glass units in custom sizes and options and ships nationwide. We ordered replacements, specifically avoiding any internal coatings.
Using them, it was fairly simple to cut away the old foam tape with a special glazing knife tool, clean the surface, then apply new tape and pull the new window glass in place... at least for most of the windows.
The exception and head-scratcher was this one large picture window at the top of a two-story room.
How could we remove the old glass and install its replacement when each unit weighed almost 300 pounds? We thought about renting a scissors lift, but the planting area outside wouldn't have made a stable base for it.
The answer kind of started as a half-hearted joke... "Can't you make some sort of pulley thing to lift it up?"
The more we thought about it, the more we thought it might be possible. I rigged up a carrier from the wood of the box the window units came in, and fastened it to two compound pulleys anchored in the eaves. Fortunately, at some point in the past, either the roofers or solar installers had added a climbing anchor on the roof, so it was possible to rig things up in relative safety.
Then, it was just a matter of lifting the hoist in place, lifting the old glass unit into the carrier (with another pulley anchored in the window opening)....
Then pulling up the replacement glass and pulling it into place with new glazing tape.It's so nice to have clear windows again.
