When my house was built and designed, they forgot completely (as they do now) that the south facing aspect of the house would gain the most sunlight. So they built the house with almost no windows on the south side. In real terms though this has protected the house from the very heavy rain and wind we get up here in the Downlands. What it has not done though it to make the most of the light, with many of the largest windows and doors on the least lit parts.
One of the few windows on the south side is the bathroom window. We have yet to put in effective passive ventilation for this room and it can get a little steamed up. A wipe with a clean cloth usually stops the big drips of water, but one thing that does annoy me is the black mold you get especially on uPVC surfaces (don't blame me for uPVC windows they were already there and I'm not going to throw something into landfill on principal).
I do have a chemical black mould remover, which smells nasty and you can just tell doesn't do me, us or the environment any good. I've also tried steam cleaning, but to be effective it needs to be done once a week and I don't fancy hauling a steam cleaner up there for that task alone. The last option considered was actually something stumbled upon almost by accident.
During the renovation of the house we went for basic white suite and white tile combination (as we could get them cheap, and found a load of tiles on Freecycle). Now I'm ok with white – it's clean, simple and well err white; but the wife – oh no – she wants a sort of black and chrome look to mingle in the white. Ok bear with me here I'm getting to the point… part of this scheme was a blind to cover the window. We wanted a blackout blind as the neighbours next door are a little creepy at times so we looked at a few (Ikea, freecycle etc) but ended up choosing our own fabric and having a blind made for us. Our fabric selection was simple – no light was to get through and it had to match the colour scheme – in this case black.
Getting to the point of this blog though, the black blind is thick and matt and it absorbs a surprising amount of heat. This heat when applied over a period of time is enough to dry out the window area and keep just about all of the horrid black mould at bay. You do need to leave the blind down during the day for it to work, but we are mostly out during the day so it's not a problem.
So my tip here is that to cut down on the black mould and damp issues around your south facing bathroom windows (I wonder how many people actually have south facing bathroom windows?) try using a thick matt black blind and leave it down when your not in the house to let the sunlight kill off the mould for you.