The refinance is going to leave us with about $20k left over, after the improvements.

I'm a fan of buying equity and then forcing more equity through improvements. 

If truly all it needs is a new roof to be complete and ready to sell then a few ideas off the top of my head could be:1)  Borrow the money from friends or family to replace the roof2)  Put the cost of the roof on a no/low interest credit card and pay it off as soon as the house sells3)  Go through a home improvement store (like Home Depot) that offers financing for larger projects like roof replacement4)  Don't replace the roof and just lower your sales price or offer the buyers a credit to fix it themselves after closing

Being in the home improvement business as a contractor since 1992 I have helped many investors and homeowners in my area in all phases of home improvement.

Since you would have more units, you would have more scale on depreciation of appliances and improvements like a parking lot or security lighting that you may not have on a SFR.

Also is area improving.

Things will improve as the light rail expands but that is still a ways off. 

I think we probably over improve in our market in CA, but we have been successful at the BRRRR and it is easy to force the equity, which we have to or all of our cash for the down would be stuck.

As we've scaled operations, we've significantly improved our origination process, from application through closing and repayment.

Take land purchase, legal costs, expected rent, tenant improvements, any leasing commissions paid to broker, etc. and find out cap rate you want.