Insulating shipping container homes is best done on the outside to protect the container from rusting and moisture buildup on the inside UNLESS insulating spray foam is used on inside walls.

Traditionally home insulating is done on the inside with fiberglass batts or rock wool, insulating a container home in this way leads only to corrosion and condensation on the inside walls due to moister infiltration thru interior finish and vapor barrier.

Insulating a shipping container house is best done with insulating spray foam or Polyurethane Foam; this insulating material sticks to steel walls and depending on thickness sprayed, you can expect R3.5 per inch for open cell or R7 for closed cell foam per inch.

Spray Foam Insulation rust proofs the interior walls, seals the building and eliminates energy robbing cold air infiltration and the related problems with mold, mildew and condensation problems, steel is an excellent conductor, therefore it’s also a good idea to give the outside a thin layer of insulating foam to prevent bridging.

A price indication for spray foam insulation (depending where you live), $0.50+ for open cell per sq.ft/inch thickness or $1.20+ for closed cell per sq.ft/inch thickness.

Ceramic and Papercrete Insulating on the outside of container homes
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