Why this usually happens
Sprinklers or irrigation hitting the glass and drying in the sun.
Run-off carrying minerals from concrete, brick, or screens.
Rain and condensation drying repeatedly in the same spots.
Why you should not ignore it
Left too long, mineral deposits etch into the glass and become permanent — at which point cleaning cannot fully remove them. Catching it earlier means it comes off cleanly. It also makes a newer or freshly cleaned home look neglected.
In Durham Region, hard water staining often appears on lower windows near irrigation systems, basement windows below runoff paths, storefront glass close to concrete, and panes that receive repeated spray from landscaping. The sooner the mineral buildup is addressed, the better the chance of restoring a clear finish without permanent etching.
What to do next
- Regular soap and water will not touch mineral buildup, and abrasive scrubbing can scratch the glass.
- Removal needs the right solution and technique to dissolve the minerals safely — and adjusting sprinklers so they stop hitting the glass prevents it coming back.
A safe exterior cleaning approach
Our window cleaning removes hard water staining and leaves spot-free glass — and we'll point out the source so it does not return. Serving Durham Region.
Related DSS services and local pages
Frequently asked questions
Can all hard water stains be removed?
If caught before they etch the glass, yes; long-term deposits can permanently etch glass.
What causes it in the first place?
Usually sprinklers or run-off drying on the glass.
How do I prevent it?
Keep sprinklers off the windows and have glass cleaned periodically.