Probably decreases, assuming everything is working as planned. Mycelium building materials will need to be kept dry in order to prevent them from consuming their media and sprouting mushrooms, and these dry conditions would prevent mold. Additionally, the mold and mycelium would compete for the same nutrients, with the mycelium already far more established.
If too much moisture gets in though, it's game over. Perhaps the mycelium bricks/plates can be coated in a sealant.
If too much moisture gets in though, it's game over. Perhaps the mycelium bricks/plates can be coated in a sealant.