Well, this isn't a surprise for me, as I anyway thought that there hardly is a way to completely remove the fungi. Some spores will anyway stay hidden, waiting to activate when the conditions are favourable. So, probably the best I can do is to regularly monitor the situation, try to keep the conditions (temperature, humidity, ventilation) non-favourable for the fungus growth, and then remove any new growth if such appears.

Hehe, this is also a little bit like debugging software; if something doesn't work, then one needs to look for the reasons. And once the reasons are found, it often becomes apparent what needs to be done to fix the issue. In this picture we see that the fungi is growing right next to a ventilation flue. This makes it clear that there is not enough ventilation; probably the flue would need to be bigger, and maybe it would also be good to have more of them. The fungi loves still air, but doesn't like to grow is there is constant draft.

And another lesson learned is that my monitoring schedule has not been strict and regular enough. If I remember correctly, in the earlier blog post about fighting the fungi I was planning something like constantly monitoring temperature and humidity with a raspberry pi system. Alas, that never happened (mostly, because I didn't find a clear idea how to best power the system. I'd love to have a 12V battery-powered system for indoor lights and raspi systems, but so far I haven't invested money in building the infrastructure). And, an ideal system would have a powerful light and a camera under the floor, so that it would be possible to visually check the situation without removing some of the floor planks.

All in all, I'd guess this means that one more time I need to de-construct and to re-build the floor and the supporting structures, in both of the rooms. And to build it back better, planning the entire structure so that there is maximal air circulation. That is a lot of work and requires some materials to be bought. Not going to happen this summer, but maybe the next year...