Today I inspected a newly built townhome. In the Attic the sheathing and framing are “painted” with a hard shiny shelac? All I can think is this will hold water next to the wood and cause a mold issue. Any thoughts as to why a builder would do this, or what it is?
Was this the model home? Sometimes they’ll do all sorts of things to gussy up the place to make it more appealing for people who are touring the model. I’ve seen unfinished bonus rooms that have had the OSB flooring poly’d, which was either for looks or so they could mop it once in a while to get the dust up from the foot traffic.
My vote is for mold encapsulation. I have seen this done when there is mold from wet framing lumber. This could also be a preventative measure, but it is costly. I have done post clearance for new builds and failed them for this type of encapsulation. The framing needs to be bare. Call it out as suspect, and follow up with the builder to get an explanation of the coating.