When does basement wall framing demand pressure-treated wood?
This subject house was built in 1956 and the basement was recently "finished." At least that's what the house features list touted.
The "finished" basement had many things left unfinished. Like wiring that wasn't hooked up, holes left in the walls where wiring was fished, no handrail or guardrail on the staircase, and various wood moldings not completed.
But there were various signs that the basement was not finished professionally, indicating, therefore, that there was never a permit pulled.
One big sign was that none of the sill plates had used pressure-treated wood.
In new construction, or remodels, a pressure-treated sill plate is demanded.
The sill plate is the lowest point of the stud wall which is nailed to the concrete floor.
Concrete stays wetter than wood for over a century.
As such, its moisture will migrate to the wood.
Pressure-treated wood is not so susceptible to moisture damage, and therefore rot, or insect infestation, and so it is required at the bottoms of stud walls.
The sill plates in this location are indicated by the yellow arrows. That pressure-treated wood was not used is an amateur mistake. It also would have been required in this jurisdiction had a permit been pulled.
Regular wood is not acceptable, by the local code and by modern building best practices.
This regular wood was all over the basement where I could see behind the walls. Therefore it was also likely used for the stud walls that were hidden by drywall and I could not see the sill plate.
My recommendation: sellers often see home inspectors as Nazi figures with bad eyesight, mean faces and a little mustache, bedecked with brown shirts and tall boots, and running around with a book of minutia that they can point to and ding the seller's house and everything in it. While not true, home inspectors are obligated to point out things that are dangerous or not properly done. Pressure-treated sill plates are necessary now, and should be used in basements with any wood resting on a concrete floor.
Doing so is both important and a construction Best Practice.