Just as the laws of a leprous person aren't about Hansen's Disease, the laws of a leprous house in Leviticus 14 aren't about mold. Read the passage carefully. Mold doesn't fit the description.

Then the priest shall command that they empty the house before the priest goes to examine the disease, lest all that is in the house be declared unclean. And afterward the priest shall go in to see the house.
Leviticus 14:36

When your house is infected with tzaraat (leprosy possibly caused by evil speech), the only remedy is to empty the house and examine every part of your life in full public view. Without confession and repentance, there is no remission of sin.

If a house (or a person!) cannot be cleansed of spiritual disease, then it must be permanently separated from the rest of God's people, sometimes by total destruction.
Leviticus 14:45