How to Clean Window Sills

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Dear Home-Ec 101,
I bought a lovely old home with large windows, but I am at a loss over my window sills.  How on earth do you keep window sills clean?  I leave my windows open as much as possible, and while I dust them regularly with a feather duster or cloth, there are lots of corners, cracks and crevices where dirt accumulates.  Liquid sprays seem to make the problem worse.  I’m hoping to avoid stripping all of the paint and starting over, and there are so many layers already that adding another coat would only be a temporary fix.
Sills Stink!

how to clean window tracks and sills

Heather says:

I feel your pain. It’s been quite a while since my windows have received the attention they need and lately I keep the shades down in the sunroom -the official reason is to reduce solar heating, but the side benefit is no one can see my window sills.

Just to be sure we are all on the same page, let’s go over some -not all- basic

anatomy of a window:

  • Pane or Lite – the glass
  • Muntin – in windows that have separate panes, these are the usually wooden dividers that hold the panes in place
  • Snap-in Grilles- the aesthetic dividers found in windows that are actually a single pane of glass made to look like many, these can be between the panes or on the inside or outside.
  • Sash – refers to each unit that holds the glass in place – in some windows you have an upper and lower sash
  • Track – (loose definition, may have some incorrect technical points) the dirtiest, most obnoxious part of the window, designed to catch filth its actual function is to allow the sashes to move and contains the space between the sash and the screen that collects bugs
  • Frame – acts as a housing for the sashes
  • Sills – are the horizontal ledges that form the bottom of the frame
  • Stool – On the bottom of a window, this is the interior, decorative lip on which the window sits (yay for awkward sentence structure)
  • Apron – this is decorative framework below the stool

Now that we have our anatomy down, let’s talk cleaning.

I didn’t want to suggest a cleaning method for the track that is inadequate nor do I want to suggest a method that could damage your interior trim work, the stool and apron.

The general idea for both cleaning suggestions is to get rid of as much dry dirt as possible before adding liquid to the mix. Water and dirt make mud and that is a pain in the rear to remove.

General precaution:
Water and wood can be a tricky combination. Use common sense, do NOT soak your work area. Work quickly to reduce the amount of water you are exposing the wood to and dry thoroughly when finished. Do not empty your bucket into your window frame and call me crying saying your insulation and dry wall are wet.

Just as an FYI, the cleaning techniques outlined are NOT weekly cleaning techniques. This is the once a year (or every few years, if you are me) kind of cleaning.

Window Track Cleaning Tools

  • A vacuum with a hose attachment, a shop vac will work fine
  • A stiff bristled (nylon, not metal) brush like a grout brush there are specific track brushes
  • A bucket (preferably two) one with warm water with a squirt of dish detergent and a splash of laundry detergent, the second bucket is for plain water to rinse the brush / rag and keep the first from becoming horrendously filthy
  • A damp rag
  • A butter or putty knife to get into the crevices, if you must, but it needs to be wrapped in the rag or you may damage the track

Window Track Cleaning Technique

Open the window and remove the screen, if possible. Brush or vacuum the loose filth -bugs, cobwebs, etc. Vacuum these up and try not to squeal or make other silly noises if any of the bugs happen to decide they are alive. Once all of the loose dirt has been removed dip your brush into the soapy water, scrub the track, rinse the brush, and wipe away the soapy reside with the damp rag. You’ll need to frequently rinse the rag, soap residue is sticky so don’t skip this step or the track will be an even better dirt magnet. Replace the screen and congratulate yourself for getting around to the job after X years.

Window Stool / Apron Cleaning (Interior Sills) Tools

  • Vacuum with the soft bristle attachment
  • Soft bristled paint brush (I like the two inch size) x 2 -assuming you’re cleaning more than one window
  • damp rag
  • two buckets, one filled with plain warm water, the other with water and a squirt of both dish detergent (like Dawn) and laundry detergent (like Tide, but nothing with bleach)
  • dry rag
  • For the exceptionally detailed only rubbing alcohol and cotton swabs

Window Track Cleaning Technique

Run the vacuum’s soft bristle brush (with the appliance on, naturally) over the window’s stool and apron. While you have everything out, you may as well vacuum the whole interior frame. Use the dry, soft bristled paint brush to sweep as dirt as possible out of any crevices.

Dip the other paint brush in the soapy water and use this to swish any dirt out of the crevices. Follow up with a quick rinse with the damp, clean rag.

Finally, if your windows are painted white and there is still dirt in the crevice, you can use a cotton swab dipped in rubbing alcohol to get that last tiny bit. This technique often takes a tiny bit of paint, so be judicious.

clean windows
Click the picture for more tips!

Run a dry rag over the wood and pat yourself on the back.

The good news: Regular dusting will help prevent the dirt from collecting.

The bad news: Windows naturally act as dust magnets; eventually you will have to repeat the process.

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