Replies

1. Expert Member
   Dana Dorsett | Jun 25, 2019 02:29pm | #1

   There is a map that covers Canada & US, but it's not very accurate:

   https://www.greenbuildingadvisor.com/article/climate-zone-map-including-canada

   If you look at the most recent 25 year data history, Toronto is on the cool edge of zone 5, defined as as 3000 - 4000 HDDC (base 18C):

   https://toronto.weatherstats.ca/metrics/hdd.html (scroll down to the bottom for annual HDD)

   https://www.greenbuildingadvisor.com/article/all-about-climate-zones

   If the foam is the pink or blue stuff, at 2" it already meets the NBC definition of vapour barrier. If the only discontinuity is at the drainage lines (which are also impermeable to water) the total amount of area is small. That said, concrete doesn't need to "breathe", it is not damaged by moisture even when saturated. (They build bridge foundations out of it, after all.) If installing a wood subfoor or other flooring susceptible to moisture damage a layer of 6 mil polyethylene is pretty cheap insurance, even if not absolutely essential.

2. 
   sunstone | Jun 25, 2019 03:25pm | #2

   Thanks Dana, for the charts,maps and data. All bookmarked under 'EE'
   After a concrete floor poured, is it advisable to delay framing of walls or any other steps. Flooring eventually or spray foaming of the walls (rubble fdn with dimple mat cover to ground level