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Ask Dr. Laundry

Ask Dr. Laundry

Outdoor Mold & Mildew

By Dr. Laundry April 22, 2015

We love our home, a 95 year old bungalow with a stucco exterior and beautiful old-glass windows.  What I don’t love is how every winter the north-facing front of the house gets no sun!  It’s the perfect environment for mold and mildew to develop, especially the areas with no protection from the roof. Fortunately Clorox® Regular-Bleach makes cleaning mold and mildew from outdoor surfaces so easy.  I do this every spring, and thought it would be fun to share one of my favorite non-laundry uses for my favorite laundry product!

You’ll need:

  • 5 gallon bucket
  • Clorox® Regular-Bleach
  • Measuring cup
  • Rubber gloves
  • Safety glasses
  • Scrubbing brushes (long handle and/or handheld)
  • Garden hose with spray nozzle

Here’s the procedure:

  • Thoroughly water any plants near the area where you will be working. Protect larger plants by covering them with plastic sheeting.
  • Add ¾ cup Clorox® Regular-Bleach to 1 gallon water in the 5 gallon bucket. For larger jobs, use 1½ cups bleach added to 2 gallons of water.
  • Pre-wet the surface to be cleaned with water
  • Apply the bleach and water solution to the surface with a scrub brush.
  • Reapply as needed to keep the surface wet for 5 minutes
  • Rinse the treated area thoroughly
  • Let surfaces air dry
  • Re-water any nearby plants that may be getting run-off

Clean-up is super easy. Any leftover bleach and water solution can be easily flushed down the toilet. Rinse out your brushes and rinse off your gloves and boots with the garden hose, and let everything air dry. You can also use this technique to clean siding, as well as sealed brick and patio stones. Note that you should avoid applying the bleach solution in direct sunlight or to unfinished wood. The solution should not be used for aluminum gutters or windows; rinse thoroughly if any contact occurs. You should also test the bleach solution on the area you want to treat in an inconspicuous area before starting your project. Sure, it sounds easy enough, and really, it actually is! Here’s a picture tutorial to help you see how it’s done.

Mold and mildew builds up a little at a time over the winter. There’s less daylight and lousy weather, making it easier to put off dealing with (until you can’t any longer!).

I use a large plastic tarp to protect the shrub next to the wall:

I like to make up 2 gallons of the bleach solution, so I use 1½ cups of bleach. This makes it easier to dip a long handled brush into the solution. Also, notice the lines on the side of my 5 gallon bucket — I used an old milk container to measure water into the bucket and mark volume lines on the outside so it’s easy for me to just use the hose to fill the bucket to the correct volume. No guessing as to how much a gallon is!

Getting the surface wet with the garden hose. When it’s wet, the discoloration looks even worse — yuck!

The less you have to think about what you are wearing while you are working the better. Rubber rain boots and old clothes that you won’t mind getting any bleach splashes on (I use my painting clothes) are perfect. Here I am putting on my gloves before I begin working with the bleach solution:

The long handled brush helps me easily apply (and reapply by just dipping the brush back in the bucket) the bleach solution to the wall:

Some corners really can only be scrubbed with a hand-held brush. The gloves are really nice to have here:

If you have a large area to clean, don’t try to do it all at once. To stay within the recommended 5 minutes of contact time, work in smaller sections, rinsing the first area before starting again on the next. It’s been 5 minutes so time to rinse the area I’ve worked on so far:

Wow — what a difference. Once I finish the other side it will look so much better!

Thanks, Clorox® Regular-Bleach! I couldn’t have done it without you!