How To Clean Windows Best From The Outside

“All that rubbing isn’t a good idea,” says Brent Weingard, owner of Expert Window Cleaners in New York City. “You’re just moving dirt around from one spot to another and putting a static charge on the glass, which attracts dust and dirt. As soon as you finish, the window looks dirty again.” As Weingard demonstrates, it’s easier and more effective to clean windows like the pros do: with a squeegee and a few other readily available tools. The techniques aren’t complicated, he says, and the results may surprise you. “I don’t know of anything that can transform living spaces so well. You don’t know what you’re missing until you do the windows,” says Weingard. Here are two 3-step methods for how to get streak-free windows at home; one for picture windows and another for multipane windows. Got stubborn spots? Refer to the last section to help you with those.

For Picture Windows

Step 1: Wash with a strip applicator

Picture windows call for large tools. The long cloth head of a strip applicator soaks up a lot of soapy water and knocks dirt loose without scratching the glass. For a cleaning solution, Weingard uses just a squirt of dishwashing liquid in a bucket of warm water—the less suds, the better.

Step 2: Wipe clean with a squeegee

Starting at the top left, pull the squeegee over the soapy pane in a reverse-S pattern (left-handers would start at the top right). At the end of each stroke, wipe the squeegee’s blade clean with a lint-free rag. Cloth diapers or old linen napkins are perfect for this task.

Step 3: Dry off remaining drips

Remove any water remaining on the edges of the glass with a damp, wrung-dry chamois, which soaks up wetness without leaving streaks. Dry the windowsill with a rag.

For Multipane Windows

Step 1: Customize the squeegee

To clean a divided-light window, you need a squeegee that fits the panes. Weingard uses a hacksaw to cut one to size. He trims the metal channel ¼ inch narrower than the window pane, then files the cut edges smooth. With a utility knife, he cuts the rubber blade to the pane’s full width and fits it into the channel so that it projects 1/8 inch at each end.

Step 2: Scrub the panes

A handheld sponge or hog-bristle brush works best on multipane windows. Weingard prefers natural sponges. “They’re firmer and more absorbent than synthetics,” he says. Using the same solution of a squirt of liquid soap in water, he rubs each pane from left to right, top to bottom, working the sponge edges or brush bristles into the corners to loosen dirt.

Step 3: Wipe clean with a squeegee

Pull the squeegee down each pane in a single stroke from top to bottom. After each stroke, clean the blade with a rag so it doesn’t leave streaks. (If the squeegee squeaks a lot, add a bit more soap to the water.) As above, remove any streaks on the glass with a chamois and dry the muntins and sill with a rag.

Getting rid of stubborn spots

Over time, hard-water runoff from masonry or rain falling through metal window screens leaves stubborn mineral stains on glass that normal washing can’t erase. So after a regular cleaning, Weingard wets the glass and gently “supercleans” it either with fine 000 steel wool (if the panes are small) or with Barkeeper’s Friend, which contains oxalic acid. (Other brands of powder may scratch the glass or fail to remove stains.) He mixes the powder into a paste on a wet towel, rubs away the stains, then rinses and squeegees the glass twice to remove the residue. Even with that treatment, the staining generally comes back in about six months. To get rid of stains for good, Weingard recommends the application of 3 Star Barrier Glass Surface Protectant, a clear polymer coating. “After the stains are gone, you just put the coating on with a strip applicator and squeegee it off,” he says. Protection against staining is permanent, as long as the polymer is reapplied after each regular cleaning.

Tools