Soon to be foreclosed upon home owners and disgruntled tenants sometimes sell them too, as part of their process of trashing the house".Is this practice common everywhere?

Don't feel that you need to do everything yourself, because that's really not possible or practical.

I consider this common practice and the couple rehabbers I source deals for use them as well, and we see it as standard rehab lending.

That said, there are privacy laws in place and industry practices that lead to a slow reveal of this information.

@Amanda Young -My biggest way to balance kids sports activities and investing right now is an iPad with a data plan for researching properties and addressing email during the time I wait at practices.

This will give you a good idea on what is common practice in your area.Here, it really varies.

Done right, a grow op can be done with a small environmental footprint, but as @John D. points out, there are structural limitations to the house that might not allow best practices, in which case a lot of harm can be done.  

My following comments are my opinion based on years of practice and do not constitute legal advice. 

More importantly, an awesome business paradigm based on ethical practices and using the wisdom of 'seed' planting.

Hoping to speak with a contractor but wanted a sense of practicality before going into the discussion.