Foam vs Fiberglass – Shipping Container Insulation

Shipping Containers, Storage Containers, Container Modifications & Mobile Office Units for Sale

Published In : 12-October-2023

Shipping containers have become popular sustainable solutions for housing and portable offices. However, insulation is needed to control the temperature on the interior of the container. Storage containers for sale are strong and durable, but the walls are rather thin. Modifying a cargo container with proper insulation can be done in several ways, but two materials provide the best options.

Note: Insulation ratings are measured in R-values, which reflect how well insulation can prevent the flow of heat. A higher R-value means more effective insulation.


Spray foam is the quickest, easiest, and most efficient way to insulate a shipping container. This insulation material totally covers the corrugated shipping container walls without leaving any gaps. Providing the highest insulation value of R-6 per inch, closed cell spray foam can be applied as thick as needed. Although this is the preferred insulation method, closed cell spray foam can be the most costly due to labor and materials.

Another option with this material is foam panels, which have an insulating value of R-5 per inch. These panels can be glued to the shipping container walls or screwed into a mounted flat bar, which we recommend. Foam panels come in various sizes and thickness, depending on how the unit will be used.


Found in many homes and container offices, fiberglass batt is a commonly used material for insulation with a value of R-13 and 3 ½” thick . The interior is framed with 2 x 4 wood studs (typically 16” on-center), then filled with fiberglass batt insulation. The walls can be finished with an FRP (fiberglass reinforced plastic) plywood or HardiePanel® (a factory primed, compressed fiber cement board).

If you would like to speak with a container specialist about shipping container for sale or storage container for rent, one is standing by to answer any questions you may have. Feel free to call us today at (877) 670-0229 or complete an online quote request.

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