Things like a new roof can range - here in Philadelphia where i do a lot of work, our flat rubber rowhome roofs are fairly inexpensive and standard . . .

After 5 months we had a bad water leak under the house.

Your PM replaced the water heater because it was leaking.

No guaranteed way to stop a determined, experienced thief:(Only deterrents that push them to easier jobs.The roof may be a good idea - until they figure out the just need a ladder to get up there and a rope to lower it down. 

Based on rough assessment, the following is needed just to get it listed:NeedsLowMidHighRoof$7,747.00$12,580.00$26,037.00Siding$20,000.00$25,000.00$30,000.00Windows$9,000.00$12,000.00$18,000.00New Deck$8,000.00$10,000.00$12,000.00Roof Leak Repair$2,000.00$3,500.00$5,000.00Mold Mitigation$1,000.00$2,500.00$3,500.00AC Units$13,000.00$15,000.00$18,000.00Carpet Replacement$2,500.00$3,500.00$5,000.00Kitchen Remodel$5,000.00$10,000.00$20,000.00Total$68,247.00$94,080.00$137,537.00Due to lack of capital to fund these repairs, I believe the best option is to find an investor looking to flip. 

Doing few roof for single family homes in Houston.

What the city housing clerk is telling me is that there was a water leak from behind the sink pedestal on the second floor bathroom that has been running for a week. 

I just bought it in the fall and am trying to complete a bunch of modifications during off-season (e.g. metal roof, certain safety features, treating the deck, possibly updating the fire pit area, etc). 

The best defense against rats entering your property is to seal off all entry points (holes, cracks in walls), remove food sources (dirty dishes, food left in trash cans), and water sources (like leaks). 

Schedule a property walkthrough with the tenant, giving the proper state notice, to determine if the problem is due to cleanliness issues, leaks, unsealed perimeter entry points.