Life in the mould lane – Mouldy Japan

 When I arrived in Saga, I was warned multiple times about mould by my seniors. I sat through a “welcome to Saga” PowerPoint with tips and hints on how to prevent mould from growing in my apartment. However, in the two years I lived in Saga, I never experienced any mould in my home, so much so that when I moved to Fukushima, I had forgotten about the warnings. Saga has very hot summers, and that heat extends into spring and autumn. Perhaps also because my home was a concrete building with good ventilation, my house was spared from the spores of the mouldy overlords.

Japan is especially prone to mould, thanks to a combination of climate and architecture. The main culprit is the country’s extreme humidity, which soars to 100% during the rainy season and lingers through the sweltering summer months, creating an almost year-round paradise for mould. Older buildings, with their tatami mats and paper doors or dividers, are particularly vulnerable; their traditional materials soak up moisture and provide plenty of hiding spots for spores.

But mould isn’t just a summer problem. In winter, the sharp contrast between the icy air outside and the toasty warmth inside leads to condensation on walls and windows, yet another invitation for mould to settle in. Ultimately, it’s the wild swings of Japan’s seasons, from damp to dry and hot to cold, that make mould a persistent foe in Japanese homes.

When I moved into my new apartment, I had forgotten the warnings; summer had been mild, and the place was newer. It wasn’t until a month later, when I awoke to extreme condensation everywhere, that the warnings started to haunt me. At first, I figured a few dehumidifier boxes would solve the issue. I acted promptly and had 6 in my home about a week later. However, little did I know the problem had been lurking the whole time. Hidden from my human eyes and just waiting for the moment the first condensation would hit. The first hint was when I opened a jar of jam and, a day later, went back to the jam to reuse it. I discovered black mould in the jar, and it had been a day. This was a hint at how bad the issue would become.

Fukushima's summer had been a washout. A colleague told me that the prefecture had only had 10 days of sun this summer. The prefecture in general is milder, especially when compared to Saga; however, this year has brought with it double the amount of rain. Typhoon season for Japan this year also ran into October, when it usually ends around September. To put it bluntly, the weather in Japan this year has been abnormal. Every day seemed to bring rain, and eventually I started to notice mould.

At first, a wooden shelf, but then my hat, my coat and more things. It was then that I realised the warnings were very real, and I had just been lucky in Saga. I was at war! A war with the spores; my personal items were the battleground, and I needed ammunition to fight back.

There are many in-depth blogs which offer a variety of help from locals, and soon I found myself wielding the tools to start fighting back! First were the dehumidifier boxes; the 6 I have are already full of liquid, which means new ones will be needed very soon. The next step is to master your aircon! Most modern aircons offer a range of settings, and one is joshitsu (除湿) or dorai (ドライ); this is literally a dehumidifier setting. It is advised to keep this setting on during the humid months, aka the rainy season.

The next tip is one my mother was obsessed with back in the UK, much to my displeasure, but opening windows during sunny days is highly recommended. This helps ventilate the house, and it is recommended to open windows on opposite sides of the house to cross-ventilate for even more effectiveness. But should it start to rain, windows must be closed to avoid spores coming into the home. This can be a little tricky, especially back in Saga when sudden downpours were very unpredictable. Here in Fukushima, however, right now it is safer to presume every day will have rain.

One tip I did religiously live by in Saga was to keep the bathroom/shower ventilator fan always running. This is very important; however, according to multiple sources, it is only needed for an hour after a shower. It is also important to keep doors open a little to allow air to circulate, especially in smaller rooms such as Japanese bathrooms and closets. Another tip I picked up when researching for this blog is one I will be investing in: anti-mould foggers; these act like flea bombs if you have ever owned a pet. You use them every three months in a Japanese bathroom, and they kill any mould spores in the area.

The last piece of advice is one I remembered from my “welcome to Saga” PowerPoint, and that is to keep things off the floor, aka futons. Sun futons regularly and keep things elevated. Older Japanese homes will have more of a war on their hands, and tatami is something I am glad I have never had to care for. But homes with more wooden surfaces and natural surfaces will be at a higher risk should mould invade.

The war on mould is ongoing, and my package from Amazon has finally arrived. I am now awaiting a sunny day, so I can air out my house and go crazy with spraying everywhere. It's true what they say: you never realise how lucky you were until you move into a wet, rainy prefecture full of mould.