Best Insulation Ideas for Shipping Containers

Winter is come at us full force, and a discussion that surfaces every year around this time is "what's the best way to insulate a shipping container?" As a raw building component, shipping containers provide a solid place from which to start. If you're working towards a traditional modular housing project, storm shelter, prepper cabin, or work shop the question of "how to insulate it" will, without a doubt, come to the surface.

There are three ways that people normally insulate a shipping container. Rigid foam, spray foam, and rigid mineral wool insulation. We've touched on the first two options in a previous article, "How to Insulate a Shipping Container", so we won't spend a lot of time on those two today, putting the spotlight on mineral wool insulation.

Rigid Foam Insulation: Rigid foam insulation is a good option for insulating a shipping container because it can be installed quickly and it provides a decent R factor. However, rigid foam insulation isn't ideal for two reasons. 1) The foam boards will most likely be installed on the inside of the container, and once studded out and finished you could lose a few inches in space. 2) Foam boards aren't breathable, and if any moisture or condensation gets behind your insulation and against the all of the container it could expedite rust, corrosion, or other problems that come with long term moisture problems like mold and bacteria.

Spray Foam Insulation: Spray foam insulation provides a greater R factor, and helps to solve the dampness issue, but still requires finishing and losing some of the interior space. It's also expensive and typically isn't a DIY type project.

Rigid Mineral Wool Insulation: We spoke with Todd Collins, an expert in thermal performance and the founder of A&E Building Systems of Denver Colorado, and he suggests wrapping a shipping container in rigid mineral wool insulation.

"To insulate a container, one excellent option is rigid mineral wool.  It is fire proof, vapor open and r-4+ per inch.  Mineral wool has a melting point around 2000 F making it fantastic for fire.  The vapor open part is important because if any moister gets in behind the insulation, mineral wool will allow it to dry out.  The other options out there are not vapor open and your container will rust.  And finally, you can get r-16+ from 4 inches of rigid mineral wool and more if you want more of course.  A typical 2x6 wall is arguably r-13 to r-19... arguably because the studs are thermal bridges.  You will want to cover it with a rain screen or siding of some sort to protect it."

Rigid Mineral Wool Insulation

Overall, the choice of insulation really depends on the full details of your shipping container project and the climate where it's going to reside. Heating and cooling and living or working space is an important topic to address, and if it's addressed properly the first time it could save you a lot of money, as well as hot or cold nights, in the future. No matter if you choose rigid or spray foam, or mineral wool insulation, executing the project properly is key to a successful project.

If you have any questions about shipping containers we invite you to contact any of the sellers on ContainerAuction.com, or our staff directly; if you have questions regarding insulation or building an energy efficient shipping container home contact Todd Collins at A&E Building System.