The whole process may cost $5,000, or $20,000+.
Get as many bids as possible from licensed contractors.- let them give you detailed breakdown on paper.
All but few will promise environmental clearance certificate (from 3rd party). If they don't pass the 1st time, they'll try 2nd time free of charge.
Normally it will be an easy pass, because the mold issue is basically a hype in most cases (practically every home will have a little mold) - this said, there are some really bad mold houses. You want to avoid these. But your case seems minor.
Once you have the certificate, you are set.
As far as disclosure, it is pure state law dependent.
For rental, most states do not require a disclosure. If it is required, then you have to disclose. (Disclosure will make your property less rentable or you have to accept a lower rent typically).
Either way, try to avoid family with little kids as tenants.
In the end, as long as you have clearance, your liability is contained as a landlord. Buy enough insurance coverage is always a good idea.
Hope this helps.
