Hello, my girlfriend and I are possibly purchasing a house that has an addition on the rear, and the work seems very well executed. However, this d addition is supported by 8" sonotube concrete posts, and there is crawl space under the addition. This crawl space is very restricted, between 18" and 24". I took a look underside, and the wood is clean, no traces of moisture or rot. This addition is not insulated from below. Considering the high prices of electricity, we would like to insulate the underside. Am I correct in assuming that urethane expansive foam (the purple one) would be the best insulation/vapor barrier? What would you reccomend if not this product? The home is located in Quebec, where the winters can be quite harsh. Thank you.

Does anyone know where to buy this type of door weather-stripping in the attached picture. I can't find it on Amazon.com. It's original with the house, and made of vinyl. It looks like a thin vinyl innertube configured in a C-shape.