We have no debt besides a $11k auto loan.

  $11,500 x .45 = $5,175This amount will include the full mortgage payment including taxes, insurance and mortgage insurance as well as any credit card, auto loans or student loans reporting on your credit.

Most people your age start incurring lots of debt over the next 5-10 years with student loans, credit card debt and auto payments. 

Lastly if they are both on month-to-month I would recommend that you notify them both that their leases will not auto renew and that you would gladly renegotiate a new lease for them, a new lease monthly rate, inspect your property do some nice modest but inexpensive upgrades and when you give them the new lease, you can add the language you need to minimize and address these issues and add value for your self.

Generally 10% is good, but when you take your walk through make sure to test the mechanicals and write down as many of the flaws as possible.

@Snehann KapnadakPM and I am happy to set up a time to discuss the mechanics and hot button issues!

BUT they had virtually rebuilt this entire home, every wall, window, door, hardwood flooring, siding, roof, all new mechanicals etc etc was meticulously replaced.

Never let extra work be done and just hope the bill is ok later.Whether he is a mechanic or a construction worker I’m pretty sure he could put a lien on the property but until you pay him.

On the same residential lot are 2 commercial auto shops (grandfatherd as commercial on residential lot).I started a rehab of the apartments and house immediately and have had a tenant in one of the apartments the entire time. 

I think these are simple mechanical valves, so they probably won't help will small leaks, but might help if something breaks wide open downstream of the valve.