Anybody know a good place to get these in Canada ? Specifically British Columbia or Alberta ( Driving distance from Salmon Arm ) ? These are waste cores or knock outs from fully insulated exterior doors that I want to use under the slab for insulation. Thanks

I find some at my windows company in Lac St Jean /Quebec, they are very popular , I have to put my name on a list ... so you should find some in your area or I find this too :http://isocycle.iquebec.com/ ( french only)