insulating sheathing indoors?

[<bks>]

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&#39;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&#39;ve seen it used in basements. Any worries here?

Thanks.

[buffalobill]

tell your friends it was supossed to go only on the OUTSIDE of the basement if it&#39;s this product at:

[<bks>]

so, what flat foam insulation is rated for interior use?

[buffalobill]

the worldwide web has many answers for you but your question is best answered by your local building code, easiest by the building inspector in your area. in a tropical climate or where mold is going to be a problem there is a foam concrete for example installed by an insulation company. the temperature at which various foams can be installed may be found in their specifications, often requiring 40 degrees F. or warmer. it&#39;s winter here right now in buffalo ny but you may have just the climate for this stuff today which doesn&#39;t burn. in your town they may want fiberglass batts covered by fire rated drywall or concrete board. if your farmhouse is plank construction, insulation cavities may be missing. if they are present i would look to some do-it-yourself foam canned insulation. see gun and other ideas at

[Edwin Pawlowski]

Most are. Styrofoam and expanded bead board is and they are made with fire retardant in them. By code though, they must be covered with sheetrock as they can burn if there is something to feed them with fire, otherwise, it will go out.

[Goedjn]

I&#39;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&#39;t stress about the difference.