I'm a journeyman carpenter, however I've never built a walk in freezer before. It's for family, and they decided to build one as opposed to buy a kit. I'll lay it out for you and ask my question as the end.

It's a 9x16 with 9' walls. - Two walls are also exterior 2x6 walls, which have been insulated with batt insulation and then vapour barriered. A second wall is framed inside of the freezer, which is 1 3/4", studs are offset from the exterior studs and there is a 1" air space between the walls. The air gap and the smaller wall will be spray foamed.

• there are two interior 2x4 walls. These have a second 2x4 wall (offset studs) built inside of them with a 1" air gap between them, these will also be spray foamed.

• the concrete pad is 4" thick and on top of this, there is 4" of Styrofoam sheets, atop that is a framed 2x4 floor which will be spray foamed then sheeted.

• above the freezer is a loft, so there are 2x10 joists.

Does all of this sound correct?

And for the ceiling, my thought was to throw some batt insulation between the joists, vapour barrier, then put 4" of Styrofoam insulation, then use some long screws to screw plywood to the underside of it the joists. Does this sound correct?