If you are purchasing an older home with wavy glass windows, there are a few important things you'll need to know. Old windows have problems associated with the construction of the glass and framing. The glass started out as a huge bubble and was flattened and cut to size when cooled. Due to the construction, the glass is uneven and distorted, which makes it wavy. The waviness of the old glass is what gives old windows charm.
Fortunately, there are a few things you can do to restore the windows. Here are a few common problems with old windows and solutions that will allow you to keep them.
The glass is thicker at the bottom and it distorts the view
Cause: There's a myth that old glass is thicker at the bottom of windows because glass is a liquid and gravity takes effect. However, the atoms in glass are tightly bonded together chemically, which prevents gravity from being able to pull the glass downwards. The reality of why old glass is thicker on the bottom is simply due to the way it was constructed.
Solution: Unfortunately, the only way to solve the distortion problem is by replacing the old glass with new. However, doing so will take away the charm of the old windows. If you'd like to still have a wavy appearance in the glass but with less distortion, considering replacing the glass with glass that is salvaged from another older home. Ask your window repair service about finding salvaged old glass. There are companies that remove old windows and glass from old homes and sell them.
A window is painted shut and can't be opened
Cause: Over the years, previous homeowners have painted the window sash, and this has caused the window to be glued shut. The paint may have been applied incorrectly without any concern of allowing the window to remain functional.
Solution: You'll need to cut the seal that the paint created. To do this, take a putty knife and slide it between the sash and window sill. Once you've broken through the seal, slide the putty knife the length of the window opening. Do this to all affected sides. Then try to lift the window. If the window still doesn't budge, the paint will need to be removed from the sash and sill. If this is necessary and you are not a DIY-er, it's a good idea to hire a window repair service like United Glass Service Inc so you don't accidentally damage the window due to inexperience.
The wood frame around a window is rotted
Cause: Old windows were framed with wood. However, wood can rot when there are leaks from rain or the wood gets exposed to excessive moisture, such as in the sash where the glass is thinner. Another condition that is needed for wood rot to occur is oxygen. When these conditions are present, it causes fungi to grow, which is what causes wood to rot. Varnishes and paints are used to prevent oxygen from reaching the wood which, in turn, protects wood from rotting. However, the previous owners may not have applied and/or reapplied these protective layers over time.
Solution: The rotted wood will need to be repaired with wood putty or replaced entirely, and the fungi will need to be eliminated or it will continue to grow in that area. Of course, the source of the moisture will also need to be dealt with, which could be a leak in the seal of the window pane or a crack in the framing of the window. It's important to fully inspect all framing elements of the window to check for signs of wood rot and fungi.