You might think that cleaning your home’s windows is a no-brainer, but you’d be surprised to find out how easy it is to scratch the glass in your home’s windows using improper window cleaning technique. Why? That’s because cleaning windows without damaging them requires knowledge and experience using the right tools.
So, let’s break down how this could happen, why it matters and how to clean your windows like a pro without leaving behind unsightly damage.
How Windows End up Scratched
Glass may seem tough, but it’s surprisingly vulnerable to all sorts of abrasions. Why? That’s because on the Mohs scale (a measure of mineral hardness), the glass commonly found in windows generally ranks around 5.5 to 6. That means anything harder, like steel wool, certain scrubbing pads, or even dirt and debris trapped in a rag, can etch microscopic scratches into the surface. Over time, these tiny imperfections multiply, creating haze, dullness, or even stress points that could lead to cracks.
Common Culprits of DIY Disasters
Abrasive Scrubbers
Coarse steel wool, scouring pads, brushes with metal bristles, dirty sponges and/or rough paper towels can scratch window glass. That’s because those tools are designed for tough grimes but leave behind scratches that may be seemingly invisible at first, until sunlight hits them.
Improper Drying
Dragging a dirty squeegee or using a dirty common cloth can spread grit across the glass, acting like a tiny grinding tool.
Neglecting Coated or Tempered Glass
Some modern windows have water-repellent coatings or energy-efficient films. Abrasive cleaning can strip these layers, leaving the glass more prone to scratches and reducing its functionality.
Why It Matters
Scratches aren’t just an aesthetic issue. They can:
Compromise insulation
Coatings on energy-efficient glass help regulate temperature. Scratches degrade this performance, potentially hiking energy bills.
Increase breakage risk
Deep scratches act like stress concentrators, making windows more likely to crack under temperature shifts or pressure.
Lower property value
Cloudy, scratched windows lose their “curb appeal” magic and might signal poor maintenance.
The Safe Way to Clean Windows
Choose the Right Tools
Soft microfiber cloths or squeegees with rubber blades are a good start. Clean, non-abrasive sponges (like synthetic, super-absorbent ones) can also help to mitigate grinding into the glass.
Rinse first
Wash away dust and debris before scrubbing to minimize grit.
Squeegee like a pro
Use a figure-8 motion to avoid dragging dirt across the glass.
Dry with care
Finish with a clean microfiber cloth to buff out streaks.
Tackle Hard Water Stains Safely
For mineral deposits, use a commercial glass decalker or a paste of baking soda and water. Apply gently with a soft microfiber cloth, then rinse thoroughly.
Know Your Glass
If your windows have Low-E coatings or tempered glass, check manufacturer guidelines. Some surfaces require specialized cleaners to avoid damage.
When in Doubt, Call the Pros
If you’re faced with stubborn grime on your windows, or a unique type of window glass (like leaded or antique panes), hiring a window cleaning professional could help to mitigate the risk of damage. Many companies use ammonia-free solutions and scratch-resistant tools tailored to your home’s specific glass type.