Insulating floor
GBA Editor
| Posted in General Questions on
I live in Northern Canada where Temps go down -40c I am re-insulating the floor in my mobile Home. it is now done with 6in fiberglass bats with a fabric air barrier between 10in Joists. I am putting in 4ins of Foam board tight to floor and to recycle i am reinstalling the fiberglass over this and then covering the whole thing with 1.5in of foam board. I am wondering if this would cause any problems. It may be a bit of overkill but my home is supported on wooden blocks with 1/2in skirting 6in off the ground which is code here
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
That's probably a reasonable approach. You don't say what kind of foam board: extruded polystyrene or foil-faced polyisocynurate?
To avoid a double vapor barrier, I would recommend the unfaced extruded board below and make sure it covers the bottom edge of all floor framing to prevent thermal bridging. You might also want to increase the lower foam layer to 2" to keep the framing above the dew point as much as possible, and tape the seams to keep that wind out.