After the plumbing backing up three times in the last two months with just normal use, we have had two plumbers confirm that the main line is clogged with broken pieces of toilet. 

One of the contractors said they had a new machine that could do epoxy lining of the cast iron plumbing system underneath the house.

Too, there are some advantages in the winter, as one unit has heat on and that helps keep the vacant unit a little warmer and water moving in the plumbing, so lower odds of frozen pipes. 

I have had $1,000 plumbing repair hit the same month a refrigerator needed replaced. 

The key is to get a skilled investor-friendly inspector to make sure you have good plumbing, electric, structure, roof, and mechanical systems.

St L and KC FULL of 1900s-1920 read brick buildings.I dont like them, because the plumbing, wiring and roofs often very old, plumbing and drainage is Major Capex, unless you get the property for very low price so you can allow for these Capex expenses at the front end.

If it's an older mobile home, you may need to figure in fix-up costs for items that will come up sooner or later (i.e. roof, siding, heating and air conditioning, plumbing, etc).

And you'd do the same exercise for the POH rents.You'd divide expenses such as: Fixing the plumbing in a home - that's a POH expense.

Plumbing?

It needs new fascia and gutters; needs plumbing brought up to code, needs bathroom reworked slightly with new vanities, and a new water heater; needs wiring brought up to code as part of it is on fuse box; needs new flooring; needs a complete HVAC system installed; needs a complete new interior paint job; AND has a little bit of mold in one of the front bedrooms (not black mold) due to poor drainage.