Post and Beam insulation question

[Roy Bauman]

That's how my house (in NE Ohio) is built, and we've never had a mold problem. We have R-13 in the walls, with poly just under the sheetrock, and R-40 blown in in the attic - right on top of the sheetrock. Attic is vented on both the ends and the ridge.

House is 28 years old now.

That is how it was commonly done thirty years ago but you won't find a new home around these parts done like that. Ohio is pretty much all Climate Zone 4 (except the lower part of the state) and poly is not allowed by code as an interior vapor retarder anymore. New homes are required to have an R-Value of 13 in cavity insulation plus R-5 continuous insulation outside the sheathing or a total R-Value of 20. Wall construction will typically be, from inside to out, 1/2" Gyp Board, Stud Framing (2x6 is most common now) 1/2" exterior sheathing (usually OSB) a vapor permeable weather barrier (Tyvek or other housewrap) and exterior finish material. The weather barrier will also vary based on the finish. The problem with vapor retarders in Climate zone 4 is that since it is supposed to go on the warm side of the wall, half the year it is on the wrong side.