window cleaning
Why Windows Look Dirty After Rain
Rain does not clean windows. It moves dust, pollen and roof grit onto the glass and leaves spots. Here is why, and what actually fixes it.
Rain does not clean your windows. It washes dust and pollen from the roof and siding onto the glass, and when it dries it leaves spots and streaks.
What is in the water
Rain picks up dust and pollen from the air and carries dissolved minerals. When the drops dry on the glass, the water leaves and the minerals stay behind. That is the spotted look you see after a shower.
Spring is the worst for it. Pollen settles on everything, a rain turns it into a yellow film, and then it dries on the glass. If your windows look worse after a spring shower, that is what you are seeing.
Where the dirt is coming from
Water that runs down the wall first passes over the roof edge, the gutters and the frame. It collects whatever is sitting there and brings it onto the window. If the gutter overflows, it can run straight down the glass.
Dirty frames and sills are the biggest cause. Every rain washes a little of that grit out of the frame and across the pane. This is why we clean the frames and sills, not only the glass.
Why it looks worse when wet
A film of dirt you did not notice on dry glass becomes obvious when it is wet, and low sun after a rain shows every mark. Often the glass was dirty before, and the rain only made it visible.
Old cleaning marks
Streaks can also come from the last time the windows were cleaned. Too much soap, a dirty cloth or paper towel lint will leave a film that holds dust. Dishwashing liquid is a common cause.
A quick test: if the streaks are on the outside, they will not wipe off from the inside. Check which side the problem is on before you start scrubbing.
What fixes it
Clean the glass, clean the frame, clean the sill, and keep the gutters clear so they stop running over the window. Doing only one of those gets you a few good weeks.
What to do in between cleans
If you want to tidy up between visits, wipe the sill and frame first so the grit does not end up on the glass. Use a clean cloth and a little water. Skip the soap or use very little.
For a full clean, inside and out, we are happy to come out and give you a fixed price.
Why some windows look worse than others
A window under an overhang stays dry and collects dust. A window under a gutter gets a steady drip. Windows that face the street collect road dust. Each one needs a slightly different clean, which is why we check them one by one.
What we do
- 1
We clean all the glass, inside and out.
- 2
We wipe down every frame.
- 3
We clean the sills.