Rational approach to multi-family physical inspection?

[Michael Klinger]

What would fellow investors say is a rational approach to having a (say) 50+ unit building inspected?

I am not particularly interested in knowing about loose outlet covers and those kinds of nit-picks I've seen in inspector reports. I would like to know if the roof or if the mechanicals are all going to die tomorrow.

Would you have a random sample of units inspected? Rather than every single units. Cost/time being the consideration.

Also, do you typically personally tour every unit? Is that normal/rational? Or overkill?

[Jeff Greenberg]

As@Brian Adams said we or a team member walks every unit.  The inspector checks out the major systems such as mechanical equipment, roof, foundation, parking lot electrical, pool, plumbing, etc.  They usually walk 10% of the units.  They may pick which ones or we may point them to the worst units that we saw.  They may also recommend experts in certain areas to look further at items mentioned above.