Quote:
Originally Posted by Fuzz
Interesting, don't they usually do that with garages under living spaces though? Insulate then vapour barrier on the garage side?
|
That's certainly not best practice and is against code in many locations. That's not to say people don't do it to cut corners, though really no vapor barrier in that situation would probably be preferable rather than having one on the cold side.
The proper way in a cold climate is either a vapor barrier above the joists before the subfloor goes in, spray foam which acts as a vapor barrier, or a dropped ceiling like shown here:
https://www.markham.ca/wps/wcm/conne...2-768248eec4e3
Poly sheeting on the cold side of a wall assembly in a cold climate can result in vapor going out through the wall (or floor in this case) and then condensing into liquid when it hits the cold vapor barrier. It's not the end of world, as it will tend to eventually dry towards the inside before causing too many problems, but it's certainly not the best way to do it, particularly below a bathroom.