If your Builder's Supply place has half a brain (many of ours don't), they should be able to tell you if the foam and the sheet are compatible.
Code here is a waterproof box full of insulation = skinny wall, weather sealed on both sides. Winter: -35C outside, +20C inside.
Summer's worst, last year was +47C outside and +27C in the kitchen.
Good luck with it, Sure makes a comfortable difference.
Don't forget a potting bench with some fluorescent lights for starting garden and flowering plants.
Extends your mileage.
Code here is a waterproof box full of insulation = skinny wall, weather sealed on both sides. Winter: -35C outside, +20C inside.
Summer's worst, last year was +47C outside and +27C in the kitchen.
Good luck with it, Sure makes a comfortable difference.
Don't forget a potting bench with some fluorescent lights for starting garden and flowering plants.
Extends your mileage.