It goes in and out of fashion, so wait long enough and everything comes back.

Know that sometimes the roofs are not typical, 2 of mine did not have a plywood type of layer on the surface. 

A one-size-fits-all approach to defining the rules is extraordinarily difficult in the same way that writing down all of the laws in Napoleonic fashion is virtually impossible.

If it it's more surface work, like painting, light fixtures, new cabinets, etc, you could likely accomplish it.The more likely scenario is that you have one really bad unit that you can start on either through terminating the lease or offering the tenants some kind of move off incentive.

@Keely AldingerOne other thing there is also primer stucco guys use to get stucco to adhere over painted surfaces.

@Tracey St.Julian usually a builder that builds an entire neighborhood of houses that are similar in fashion will try to get their first property sold in cash.  

Salting is also very rough to concrete surfaces, brick building masonry, etc.

I am gonna start today with good ol fashioned pen and paper to start measuring contacts, leads, and opportunities.

The directions state for hard surfaces it can be diluted with 2 parts water to 1 product, and I suppose mop it on. 

With your background instead of buying turn-key, find something that maybe has some deferred maintenance and potentially some surface renovations (paint, tile, countertops, etc).