Retrofitting spray-in insulation doesn't, but usually eliminating all of those big open spaces eliminates or severely reduces condensation.

Its like saying to the government "you got me, hand in the cookie jar, I made money."

If there are roaches or bed bugs  I will spray myself instead of calling in high dollar bug guys .even the scummiest if tenants will leave if the insects start biting them at night so that needs addressed quickly .

If you’re looking to spray foam your crawl space, I’ve used Serrano insulation.

Just because duct tape, wire, and spray foam is how your dad used to fix things, does not mean this will work.Like to paint?

They like spray and pray tactics instead of doing any real work to build a relationship.

We have taken up carpet, sprayed enzymes on floor and just painted the floor with killz.

I see a lot of Detroit investors working with Single Family Homes, duplexes, tri's and quads, but very little about larger buildings.Online I see so many of these neglected 1920's brick buildings, without windows, boarded up, spray panted, debris all around.Is there a reason these don't get fixed and flipped like the houses do?

If it is in a hard to rent area, then it might make it easier to rent.Check if it has been painted, if not, cover the flooring, spray it down (use a mister), wear a mask and safety goggles to prevent breathing it in or getting it in your eyes and then gently scrape it off. 

The stone would be a lot of work to remove, but a cheaper alternative would be to put fence pickets sprayed with a dark stain and cut to size over the wood.