Prefer spray-on type insulation. Polyurethane foam works best in combination with ceramic insulation paint. The paint is obvious for the exterior of the shipping container, while the foam is for the interior. The paint contains a special gas that contains inside bubbles, which gives it a high thermal efficiency. The spray-on foam is available in both “open-cell” and “closed-cell”. The difference is in the price tag, density, strength, R-factor and in waterproofing.
Open-cell spray foam is an air barrier, but is vapor permeable. The figure above shows the XPS insulation detail required at the above grade portion of the foundation wall for cold climate construction to minimize moisture condensation at the cold concrete in the winter months, and minimize inward driven vapor in the summer months.
Dampen for Fast Curing - Expanding polyurethane foam requires moisture to expand and cure. If you're applying foam to dry wood or other dry surfaces, or working on a day with little humidity, misting the area first will help the foam expand and cure faster. Be careful, though