On Thu, 24 Nov 2005 22:39:02 -0500, bks wrote:

I have an old farmhouse. In the 70s, the previous owner redid a room adding
insulation, rough pine-board wainscoating and then sheetrock on the top 1/2.
I'm ripping out the dark stained (and scratchy---daughter scrapes herself
all the time) pine and installing douglas fir beadboard.

Question: the beadboard is thinner than the barn board so I have to add
furring stripes or something to make it matche the sheetrock face (no
sheetrock where barn board was). Instead, I was going to beef up the
insulation---adding fanfold house sheathing (blue dow), then the waincoating
back on top. This is normally used outside, but I've seen it used in
basements. Any worries here?

I'd recommend using homasote or some other fire-treated insulating
panel-board instead of foam, unless the wainstcoating is fire-rated or
at least 3/4" thick. But I also wouldn't stress about the
difference.