May 7, 2018

How to remove mold from your windowsills

Spring time is here, and in my opinion, it could not have come sooner.  Of course, part of the reason for that is I live in yukiguni, so winter means meters of snow and a lack of sunlight for about 5 months.

With spring comes Spring Cleaning, however, so my wife and I set out to tackle some cleaning projects.  Along the way, I opened the shoji in one of my rooms to some pretty nasty stuff.

How to remove mold from your windowsills photo

Yep, that's black mold, and while ours came as a product of the long winter, condensation buildup, lack of sunlight, and lack of ventilation (and probably years of neglect from previous tenants, to be honest), mold is something that most residents in Japan will eventually have to deal with thanks to the hot and humid summers.

While prevention is always the best practice when it comes to mold, sometimes it can't be helped.  If it does come about, here's how to tackle it.

First, a list of things you'll need:


How to remove mold from your windowsills photo

There are a lot of different mold/mildew cleaners in the stores, but don't waste your time or money--stick with the good old fashioned bleach.  The characters for it are 漂白剤, but if you are looking for a brand, "Haita" worked just fine for me.

Rubber Gloves

How to remove mold from your windowsills photo

These are important just so you don't get your hands covered in mold or bleach solution.


How to remove mold from your windowsills photo

You'll want to have a bucket to place used cleaning implements.  I use a basic plastic car wash bucket that has become my go-to for any household chores.

Spray Bottle (optional)

How to remove mold from your windowsills photo

I have large window sills, so I wanted to use a spray bottle for speedier application.  Spray bottles can be risky with bleach solution because they can spray somewhere that bleach could be a problem.  Just use your best judgment given your space and equipment available.

Respirator or Mask (not pictured)

These are easy to find in Japan, but a mask or respirator is key to ensuring you don't breath in any bleach fumes or agitated mold.

Sponge or Brush (not pictured)

If you have lots of mold on the sill, you'll need to use something to remove it.  If the windowsill is finished material, I recommend using a non-abrasive sponge.  If it is unfinished, you'll need something capable of a bit of abrasion to ensure you get in all of the little nooks and crannies.

Next, here's how to get rid of that mold:

Step 1: Clear the area around the windows and ensure proper ventilation

You don't want any nice tapestry, furniture, clothes, etc. to end up with bleach on it.

Step 2: Mix the Bleach Solution

The industry recommendation is 2700 ppm available chlorine solution, but for ease of use, you're safe if you go about 1:20 bleach to water mix.  Some people recommend a higher bleach content, but I think it's overkill.

Step 3: Apply the Bleach Solution

If you're using a spray bottle, just be careful not to get the bleach solution anywhere but on the windowsill.  I recommend using liberal amounts and to go all around, even if you don't see any visible mold (this is to ensure you kill any mold spores that are not visible to the naked eye).

Step 4: Remove visible mold

Use your sponge or brush to remove any mold that is visible on the surface.

Step 5: Spray again

Step 6: Air Dry

Step 7: Repeat (as necessary)

It may take a few go's to complete the job.  For example, this was my window sill after the first cycle:

How to remove mold from your windowsills photo

Still, it only took one more go for that one to be cleaned up!

Have any questions about removing mold?  Any other recommendations for readers?  Feel free to use the comments section below!



Hitting the books once again as a Ph.D. student in Niigata Prefecture. Although I've lived in Japan many years, life as a student in this country is a first.

Blessed Dad. Lucky Husband. Happy Gaijin (most of the time).