@Peter Morgan most likely the duct above it or the connection between the duct and vent is not adequately insulated to prevent condensate from forming.

I have not been in the attic but from photos and knowledge of my own building there is not enough insulation in the attic which has caused mold to form from heat transfer through the ceiling. 

An example would be a general contractor that handles the pouring of a concrete foundation and framing the home, installing the windows and doors but contracts with a subcontractor for the roof, drywall, insulation, plumbing and electrical and paint.

I recently purchased a small lake house in IL, which is sort of vulnerable to winter temps (= very lightly insulated crawl space where all plumbing is located).

Basically you should figure to replace all of the mechanical electrical plumbing lot of places are laughing plaster with no insulation true 2x4 construction which is nominal sizing.

They require additional insulation, only tankless water heaters, only mini-split HVAC, Etc, Etc.

I think, currently anyway, that investors are shifting/protecting their wealth by buying in better-insulated cities like Raleigh/Durham, Charlotte, Greensboro, Austin, Dallas, Columbus, Indy, and anywhere else where there is job growth, population growth, property values are undervalued/affordable and they can find either cash flow or appreciation.So, to answer your question, I think the strategy is to continue to buy in these markets when the numbers make sense and not sit on the sidelines waiting.

It was a terrible buy as it's a 40's concrete house, 700sqft, and IMO rehabbing a concrete house isn't worth it due to poor insulation among other things.I have around $60k saved and am frozen on if I should pull the trigger on a deal in OR where prices are super high and use financing to rehab a buy and hold rental, or go out of state where I can buy something for cash and rehab that for a buy and hold rental. 

Need to be insulated and may have windows and door (rolling garage type of door is ideal).  

Never seen a gazebo in a desert house because they are super poor insulation from the outside heat and temp.