EcoRenovator - View Single Post - Remodeling the office (new floor, ceiling & adding insulation) passive house retrofit

gasstingy · 08-08-11, 01:23 PM

OK, let's go one step farther then. After the wall is spray foamed, before you drywall it, you add a layer of extruded polyeurethane in your choice of thickness. I know it comes in 1/2" up to 2" in my area. This takes care of that thermal bridging problem at the cost of a very minimal amount of lost room dimension. While the sprayed insulation + sheet foam insulation may not bring your number quite up to R40, I'd bet it would be quite nice and cozy.

OTOH, to meet passive house standards, mooney walls are probably the best choice. It's hard to beat a 14" or thicker wall with blown in insulation. In my area at least, homes as old as yours typically have large enough rooms that would accept a mooney wall setup without feeling cramped, with the likely exception of the bathroom.

I'll be following along on whichever choice you make.

08-08-11, 01:23 PM	#6
gasstingy Journeyman EcoRenovator Join Date: Feb 2010 Location: Arab, AL Posts: 491 Thanks: 109 Thanked 49 Times in 43 Posts	OK, let's go one step farther then. After the wall is spray foamed, before you drywall it, you add a layer of extruded polyeurethane in your choice of thickness. I know it comes in 1/2" up to 2" in my area. This takes care of that thermal bridging problem at the cost of a very minimal amount of lost room dimension. While the sprayed insulation + sheet foam insulation may not bring your number quite up to R40, I'd bet it would be quite nice and cozy. OTOH, to meet passive house standards, mooney walls are probably the best choice. It's hard to beat a 14" or thicker wall with blown in insulation. In my area at least, homes as old as yours typically have large enough rooms that would accept a mooney wall setup without feeling cramped, with the likely exception of the bathroom. I'll be following along on whichever choice you make.