What You Might Be Getting Wrong About Washing Your Windows

Let's call him Dave.

Dave is a capable guy. He built a deck. He replaced his own kitchen faucet. He is not the kind of person who shies away from home maintenance tasks. So when the snow finally melted last spring and he looked at his windows for the first time since October, he thought: how hard can this be?

He grabbed a bucket, some dish soap, a sponge from under the sink, and a roll of paper towels for drying. He started on the front window, the big one facing the street, and worked methodically, corner to corner, proud of how clean it was looking.

Then the sun came out.

Streaks. Everywhere. Not faint ones, but proper, blurry, caught-the-light-wrong streaks that made the window look worse than before he started. Dave did everything he could to wash the windows properly, but without the proper equipment, a streak-free result was impossible.

Why This Happens to Almost Everyone

The most common DIY window washing mistakes are consistent across homeowners, and the frustrating part is that they look like the right approach until the sun reveals the results.

Paper towels are the first problem. They feel absorbent and clean, but they leave lint fibres on glass, which will then go on to catch the light and create a smeared look. The same goes for old cotton rags. Professional window cleaners use lint-free microfibre cloths or properly maintained squeegees with fresh rubber blades, which pull water cleanly off the surface rather than redistributing it.

The second problem is tap water. Most Calgary households have moderately hard water, which contains mineral ions that leave deposits as water evaporates. Even if you clean perfectly, those minerals can leave a faint residue. Professional window washing services use purified or deionized water specifically because it evaporates without leaving any mineral trace behind.

The third problem, and the one that ruined Dave's morning, is cleaning in direct sunlight. When the sun hits your cleaning solution before you've had a chance to squeegee or wipe it off, it evaporates rapidly and leaves streaks baked onto the glass. Overcast days, or shaded sides of the house, are always better for DIY washing.

What Professional Window Washing Actually Involves

There's a reason window washing is a trade with its own tools and technique, specially suited to ensure windows will be left streak-free and spotless.

The water-fed pole system is the clearest example. Rather than a bucket and a sponge, professional window washers use extending poles with a brush head fed by purified water. The water does most of the work on the glass, and because it's mineral-free, it can be left to air-dry without streaking. There's no squeegee technique to master, no paper towel lint, and no racing against the sun.

Proper squeegee technique, when used, involves pulling in one direction only, wiping the blade after every stroke, and finishing the edges with a clean microfibre cloth, none of which is intuitive the first time. Professional cleaners also address the frames and sills, which homeowners often skip, and dirty frames transfer grime back onto clean glass quickly.

If your ground-floor windows are manageable and you enjoy the DIY process: microfibre cloths, purified water or a drop of dish soap, an overcast day, and patience with the squeegee.

If you have second-floor windows, large panes, or you've done the DIY version a few times and still can't get them streak-free: professional window washing might be the right fit for you.

Campbell's Cleaning offers residential window washing using professional-grade tools and purified water systems. We handle both interior and exterior glass, including those second-floor windows that seem too awkward to get to on your own. Book a one-time wash or combine it with a home cleaning for a full seasonal refresh.

Your windows will look better than Dave's. We can almost guarantee it.