There were several issues noted as relates to the roof including staining in the ceiling of one of the closets and moisture noted in the attic....That to me suggests current and past leakage...something that was never disclosed.

If you are not prepared to bring the unit up to a quality standard now, assume the tub surround issue is a likely indicator of leakage issues and possibly wood destroying insects as well, so start saving now for a big expense, and evaluate the overall plumbing and electrical systems (including replacing old outlets, switches, fixtures, and correcting any improper "handyman" work performed over the last 20 years by the prior cheapskate landlord) to plan for costly updates there.

In balloon framing you close off the top and bottom of the walls.Actually, there has been a fair amount of research (visit the Building Sciences Corporation library for one source) demonstrating that moisture - from external water penetration or air leakage (or, form the interior if open cell foam is used -  can frequently permeate the roof deck causing deterioration (rotting) of the deck itself and/or mould growth.  

Depending on wind, air leakage, insulation levels, etc you can have some variability in actual temps.

In 2017 we had a special assessment to have our decks repaired due to faulty construction and leakage issues with the commercial unit which spans all 5 residential units.

Energy audit is part of what you are seeking, to determine places where there is "leakage". http://energy.gov/public-services/homes/home-weath...

Hello BPs. Have a rookie question related to maintenance/incidents. Last week my tenant called me saying that the toilet malfunctioned and as a result it leaked water for 2 hours approximately and cause a big flood in...

They will come in and check for insulation values of door windows and walls, air leaks in the structure using a blower door test and also a duct leakage test.

It doesn't start adding up with leakage over into the next month.Example January 1,200 ( pays 1,000 in two payments ), 200 leftover for February and now 1,200 + 200 = 1,400 owed ( pays 1,100 in  2 installments), March now 1,200 + 300 = 1,500 etc.This creates a situation from where the tenant cannot recover.

This does provide a complete envelope to prevent air leakage into and out of a building.