There are various types of mold strains as well.The musty smell could also be an air circulation or tightness problem with the space.

Just an idea, could you air bnb one side of the duplex . .

Once flooring has gone through the cycle of the seasons a few times expansion/contraction really comes down to the extremes, water or  extremely dry air to see fluctuations in wood.

I was wondering if anyone here had a rental, vacation home,air bnb, etc for rent?

When they give you the estimate, also confirm who they use or recommend for the air clearance. 

But whose is it while it's "in the air". 

I plan to convert the home into 2 units (one 2/1 and a 1/1 for Air BnB) initially and then leverage the cash flow to eventually redo the large standalone garage into a 3rd rental.Currently I am rehabbing and the bathroom s are tiny as is the kitchen.

Air BnBs.

You make your money when you buy, not when you sell.ControlOne of the biggest advantages to investing in real estate opposed to any other asset class is that you are in control of the land, the mineral rights beneath the land, and the air rights above the land (a form of God's money).

The growth and energy here can be felt in the air and seen in the massive renovations.