@John Jacobus nailed it.

I just went through this process and my firewall was approved by they city, but only after I replaced all screws with cement coated fire-rated nails. 

"- DJ BenedictDavid we have disagreed on a few other post but you hit the nail on the head here.I am focused on being retired at 55 but hoping 50.

We focus on destination type tenants ( karate schools, barber shops, hair salons, nail places, restaurants, doctor offices, environmentally friendly dry cleaners, etc. ).

My houses use concrete block walls with furring strips nailed to then that then have the drywall applied on top of that.

Seems like a funky way to put hammer to nail.

Also, beware that to a man with a hammer, everything looks like a nail.  

A landlord or any other borrower is not where you should be getting a lending education, they know what they did but they don't know what all a lender does.Another issue with learning from potential borrowers, is that the borrower explains the deal to convince a private lender, they really won't get into explaining their risk exposure, that would be like talking the lender out of making the loan......ever hear a borrower tell an individual how long they may have to wait if the died, took bankruptcy or they can't finish the project because their tools got ripped off......or whatever the reason.Investors that teach folks how to lend money to them are probably most most dangerous out there, their intentions can be very good, their knowledge is not from a lender's side and they won't be hammering all the nails in.Learn from lenders, Jon has loaned money, HMLs and brokers that do a wide variety of lending are probably the best as their experience will be broader.

For example, I had to fight with another wholesaler tooth and nail about price just to make $3k.

Yeah, I know, figured someone would nail me for not being around. :) Working F/T and taking care of 3 houses and a duplex keeps a person busy.