How Do You Clean Double Glass Windows?

Let the sun shine in!

Double glass windows offer twice the insulating power, but the seals are critical. You can clean the interior and exterior sides of the double glass, but leave the insides to the professionals!

Things You'll Need

• Glass cleaner or white vinegar or ammonia
• Water
• Paper towels or lint-free rags
• A razor for paint chips or spots
• Garden hose
• Ladder

Instructions

1. 

   Older windows are usually single glass.

   Assess your window type. Windows come in all sizes and shapes and styles, and a "single glass" window was once the norm. It features just one layer of glass (two surfaces), and you would simply clean both the inside and outside of the pane of glass. This type of window loses a lot of heat, however.

   "Double glass" windows were designed to give you better insulation--keeping your house both cooler in summer and warmer in winter. With double glass windows, you have two layers of glass (four surfaces) that are sealed together around an insulating layer of air or argon or krypton gas. Think of it as a sort of sandwich, made of the two glass panes and the filling of air or gas. Each sealed unit, or sandwiched pair of panes of glass, fits into a wood or aluminum or vinyl frame. You can clean the glass surface that faces the interior of your house and the surface that faces outside, but you cannot clean the two surfaces of the glass that are sealed inside the unit.

2. 

   Know your window type.

   Clean double glass windows just as you would any other window, except that you can't get at the insides. Fortunately, as long as the seals are intact, you will never need to clean the insides. If that seal has been damaged, however, you may begin to see condensation or staining between the layers.

   Look for weep holes in the corners or evidence of water damage on the casement frame. In that case, you need a professional glass repair service--or a replacement window. (Ask about tax credits or rebates, if you are replacing windows.)

3. 

   Be careful!

   Choose a sunny day (when it is easier to see the streaks), spray the glass with the glass cleanser of your choice, and simply wipe away the dirt. Work from the top down, for best results. Whether you have a double sash, casement style, awning or tilt window, or another type, will determine how conveniently you are able to clean it. Many modern windows allow for easier cleaning of both sides from inside the house, so you don't need ladders. (If you live in a high-rise building, a professional cleaner is recommended!)

   It is likely that if you have double glass windows, you will be able to either tilt them inside or crank them wide open, in order to more efficiently clean the available surfaces.

   For the exteriors of hard-to-reach windows, consider a glass cleaner (Windex makes one, and there are others) that is meant to be fitted to your garden hose. These can be sprayed on from the ground floor and left to drip dry.

4. 

   Snap-in mullions make cleaning a breeze!

   Use a razor to carefully remove stains from the glass if your windows have old, dried-on paint or other hard-to-clean spots,. Your local hardware store can show you a sort of safety razor meant as a tool specifically for this sort of use. It comes shrouded in a metal casing, with a retractable blade.

5. Look for short-cuts. Some windows have snap-in mullions of wood or plastic, made to be easily removed for cleaning purposes. If so, gently remove the mullions, clean the larger glass units underneath, and wipe the mullions with a damp cloth.

Tips & Warnings

• Check with your window manufacturer before choosing ammonia as a cleanser. Some plastics, vinyls or other new materials in the window casings or mullions may require gentler alternatives. White vinegar and water is always a good choice.

• Use caution! If you must climb a ladder for window washing, choose the right one for the job. Never step on the very top level (marked NOT A STEP), and always be sure the ladder is firmly placed on level ground. Whenever possible, work with a second person who can spot you.

References

• Reader's Digest: Why Insulated Window Glass Fogs
• Energy Star: Insulated Glass Ratings