How to Clean Window Tracks and Sills

To clean window tracks, get the dry debris out before you add any water. A vacuum with a crevice tool and a stiff dry brush do most of the work in about a minute per window. Spraying cleaner into a dirty track first is the mistake almost everyone makes: it turns the grit and dead bugs into a paste that packs into the corners and takes three times as long to dig back out.

What is actually sitting in there

Window tracks collect four things, and they arrive from four different directions. Pollen and road dust blow in through the screen. Insects crawl in and die there, which in October around here means boxelder bugs and lady beetles. Shingle grit and flecks of old paint wash down from above the window. And in winter, condensation runs down the glass and pools at the bottom of the sash with nowhere to go.

In the Twin Cities you get a fifth every spring: the sand and salt from all winter ends up as a fine gray powder on every sill facing a street. Mixed with a little water it sets up like thin mortar in the square corners, which is why those corners are always the worst part of the job.

How to clean a window track, step by step

Open the window all the way first, and if the sash tilts in, tilt it. The difference in reach is worth the ten seconds.

Then vacuum. A crevice tool gets the length of the channel, and a stiff dry brush pushes what it cannot reach out where the vacuum can take it. An old paintbrush with the bristles cut down to about half an inch beats anything sold for this, because short bristles move packed dirt instead of bending over it.

Once the loose material is gone, warm water with a few drops of dish soap handles the rest:

• An old toothbrush scrubs the channel and the corners
• A paper towel folded over the tip of a putty knife gets into the square corners and the seam at the back of the track
• A cotton swab cleans around screw heads and latch holes
• Dry the track before you close the window

That is the whole job. No specialty cleaner does anything dish soap does not, and stronger ones cause the problems below.

The weep holes nobody knows about

Look at the bottom of the exterior side of the track and you will find small slots. Those are weep holes, and they let rain blown past the glass drain back outside. Vinyl, aluminum, and the old triple track storms on a lot of St. Paul houses all have them.

When they plug with the same crust that collects everywhere else, the water has nowhere to go and sits in the track. That is what rots a wooden sill and lifts the finish off a painted one. The window did not fail. The drain did. A straightened paperclip clears them in about ten seconds a window.

What not to use

Four things cause most of the damage I see on tracks and sills:

• Bleach on anodized aluminum. It pits the finish and leaves a chalky white bloom that does not come back off.
• Abrasive powders and steel wool. They scratch vinyl permanently, and the scratches hold dirt tighter than the smooth surface did, so the track looks dirty faster from then on.
• Oil or penetrating spray on the rollers. It picks up grit and turns into a grinding paste. If a sash binds, a dry silicone spray is the right product.
• A pressure washer aimed at a window. It drives water past the weatherstripping and into the wall. Pressure washing has real uses on concrete and siding. This is not one.

When to do it in Minnesota

October is the right month, for two reasons. The first is condensation: a clean, dry track with open weep holes handles the water that runs off cold glass all winter, and a packed one holds it against the frame for four months. The second is access, since the screens are coming off anyway and a track is twice as easy to clean with the screen out of the way. If you have not pulled them yet, there is more in our post on cleaning and storing screens before winter.

Do it once in the fall and once after the street sand is gone in spring, and the tracks never get bad enough to be a project. How that fits the rest of the year is covered in how often to clean windows in Minnesota.

Is this worth hiring out

Honestly, no, not on its own. Tracks and sills are maybe a half hour for a whole house if you stay on top of them, and nothing about the work needs a ladder or a special tool.

Where it does come up is as part of a window cleaning, since a clean pane sitting in a dirty track still looks wrong. Gleam Team wipes the sills and tracks as part of every window cleaning. We work in St. Paul, Minneapolis, and the suburbs out to about 25 miles, starting at $99 and backed by the Gleam Guarantee. When you are ready, request a free quote or book a free 10-minute consultation.