If the work is done after the tenants are placed, it is already in service so you would begin depreciating it immediately.Without looking at the the costs of replacing the siding with vinyl (and other costs relating to the property), I am going to make the assumption that the work does not qualify for any of the safe harbors under the repair regulations and thus would have to be capitalized. 

The best is to repair one of them or replace it with a mound system.

Well, @Eric Schwake, other than the tax advantages for rentals, collecting a mortgage payment from a borrower is like having a tenant who pays you monthly, doesn't ask to have anything repaired, does not move out and require you to turn over the property,  and keeps really good care of the home (mostly).

Typical repairs include: touch up paint, carpet cleaning, light bulb and filter changes etc.

I don’t think appreciation is as good a stick built and the way they are assemblied together makes them less desirable and prone to repair on the floor entry ways according to my contractor .

@Ian I LeinwandFrom a Private Money Portfolio lending aspect you would most likely have (2) options on a (2-4 unit). 1) Rehab/Fix and flip type loan if rehab/repairs are needed >$5k- Depending on experience and Credit, acquisition LTV would be between 85%-95%, estimated Interest Only rate 7.09%--9.99% w/ 1 point for 9 months.  2) Rental Loan (2-4 unit), Depending on Credit, Max 75% LTV (80-85% SFR), Estimated 5/1 ARM rate 7.125% Full AM. or 7.375% Interest Only w/1 point.  

You can learn a ton by self-managing, and by doing your own repairs. 

So you'll need to know the market well, what fixed up homes sell for, and how to generally estimate repair costs to know if you can make a deal or not. 

I feel the loss of earnest money is a cost that will save me many thousands of dollars in vacancies/repairs etc of a bad investment.My goals:I would like to replace my current income stream in the next 2-3 years.

Numbers home value20k downloan amount 165k conventional 4.5%                            Rent-$1600PMI-$45                                                                                Cash Flow-$237Insurance-$50                                                                      ($397 self manage)vacancy-5%repairs-5%cap ex-7%management-10%(being my first i would self manage)If this is a good deal.