I specifically say HONG KONG walls because the type of mildew or mold or fungus or growth or whatever you’re getting growing year after year on your walls, is not the same as the species as those in North America.  Many articles found online are from less humid and damp places around the world, so this article has a targeted geography.  I guess, if you’re living in Taiwan, South East Asia, Macau, it would apply.  The conditions would be:

• Relative humidity of 60% and more a great deal of the year
• Areas with small land masses and adjacent to water (oceans mainly - not lakes) - I’m thinking of islands here and yes, Hong Kong is an island
• Even using a dehumidifer on a regular basis will not reduce the humidity that much
• It takes forever for your clothing to dry if you’re hanging them in your house (I don’t have the luxury of a balcony at the moment, so the clothes go into the guest washroom and the dehumidifer is blasted full the whole night.  Sorry, we have no room for another appliance such as a dryer)

Let’s start with the basics.  Why is this happening?  (Why does it happen to ME?!)  Where I live, it’s right beside the shore.  Within about fifty feet, I can walk into the Ocean.  What’s worse is that there is usually a southern-west wind that sometimes blows moist air from the ocean, onto the island, and goshdarnit, I happen to be in the way.

Mildew or mold will grow on any surface that is damp.  They normally grow well in areas with temperatures ranging from 50 to 95 degress F (or 10 to 32+ degrees C), but the damper the better.  Well, they must have started from something?  The spores don’t just spawn out of thin air!  And that is absolutely true.  The microscopic mold spores travel through the air and when they land on damp organize materials (such as wood, paper, cotton, clothing, feathers, hair, rubber, whatever), they begin to digest the material.  Gross. 

There is no real practical way to prevent or eliminate mold growth and spread.  When it gets humid, use an air conditioner or a dehumidifier to reduce the humidity indoors.  This is particularly applicable to closets that can help bake a moldy environment (check out some of your infrequently worn jackets - I recently did and most, if not all had to go through a serious dry cleaning session).  But this also means you need a system to reduce the amount of mold spores entering your house - air filtration and air conditioners can do this job as well.  So I guess there’s no such thing as fresh air from the window huh?  Well, given the air quality in Hong Kong, you might as well breathe recycled air because it’s healthier.

Fine, let’s talk about when you’re already too late and you’ve got the stuff growing (and clearly visible on your walls).  Here I’d like to present exhibit A, B and C.  Taken a few weeks ago from my bedroom wall (right above Victoria’s crib!!!).  It’s easy to spot the spores - they are obvious to the naked eye and especially when viewed from an angle, look like dirt.  Sometimes, you’ll even see little insects (I do!!) eating the mold.  These bugs are tiny, but they do move.  Using a bright light (LED flashlight) is a good way to verify that your eyes are not playing tricks on you.   The mildew usually grows on the upper portions of the walls and sometimes on the ceilings.

Everytime I see it, I freak out.  But there is a solution.  Some people will tell you to wipe the walls with a mix of various items.  I’ve heard bleach, hot water, detergent, soap, windex, whatever.  Truthfully though, after 4 years of living through season after season of mold growth - straight 100% chlorine bleach works everytime.  I have tried 1 part hot water, 1 part bleach:  2 parts hot water, 1 part bleach, but the growth returns after a few weeks and I’m worrying all over again.  There is nothing like pure straight bleach to do the job.  The only catch is that you have to clear the house of people (no children or pets) and you have to air the house for a few hours.  Use a clean cloth and scrub (not wipe) the walls with it drenched in bleach.  Obviously, you have to wring the cloth so you don’t have bleach dripping down the walls.  But this is effective for Hong Kong mold.

Of course, the assumption is that your walls are already based with mildew-resistant plaster and paint (which mine are).  Resistant and “proof” are not the same.  Like water resistant and water proof.  There are websites that recommend you repaint layers of mildew resistant paint on top of a clean wall - but after speaking with some construction guys and exterminators (who actually recommended this method instead of going through his company), they don’t recommend putting more paint on the walls because for starters, the spores may still be there (just not visible to the naked eye) and that’s not the most ideal way to repaint walls. 

So in short.  The control of mold on your walls is a combination of elimination and prevention.  There is no fool proof way to ensure it doesn’t return (it does every year for me - even after extreme usage of air conditioning, de-humidifer and bleaching the walls to death).  It simply is part of the environment, but I do try to eliminate is as soon as possible.  You can also be proactive to the situation by bleaching your walls before rainy/humid season hits (like now - early April).  But you have to at least be reactive to the situation because mold spores can be potentially damaging to your health - especially in children and babies.  To name a few:

• Asthma or increased irritation of asthma sufferers
• Irritation of tissues
• Infections
• Toxic effects due to the mycotoxins (the toxins released from mold spores)

So away you go, inspect your walls and support the bleach industry.  Don’t forget to wear gloves and a mask.  Short term pain for long term gain.   If you do have any suggestions that you have tried and they do work, please share it!!  Maybe my approach is lame and retarded because there are solutions out there that are more effective and work faster - if there are, you’ve just made my day.

Update:  Please read my post on “Prevention of Mold Growth in The House“