How to Insulate a Shipping Container - 5 Commonly Used Methods
There are various things to consider when buying a shipping container, including cost, size, condition, usage, security, surface prep, location, accessories, and maintenance. All these variables are important and should be on your mind before you start searching for and then purchasing a shipping container.
One critical element commonly overlooked when planning a shipping container purchase is insulation. Much like a home’s attic, basement, or main structure itself, insulation is necessary to control the shipping container's temperature and moisture. Whether the shipping container is used to store belongings of different kinds or converted into a home or business, maintaining the right environment inside is critical. If you decide to skip the insulation to save a few bucks, you might regret it later when condensation ruins your contents or your shipping container starts to corrode. Or you might end up spending a lot of money later on heating and cooling.
There are several different ways of insulating your shipping container. Let’s examine a few of the most commonly used options.
1. Foam Insulation
An easy, effective, and flexible way to keep your shipping container warm in cooler months and dry in damper months is to use spray foam insulation. This type of insulation combats condensation and creates a seamless vapor barrier. The foam is really flexible and makes it easy to reach into gaps of all shapes and sizes.
Spray foam insulation can be applied on both external and internal walls of your shipping container and can be used underneath the shipping container to stop any ground moisture from seeping in. Once the foam has dried, you can paint over it to give your shipping container a fresh and finished look. Spray foam insulation is a bit more expensive and a lot messier to work with compared to other insulation methods. Spray foam insulation expands upon application and then hardens, further sealing. However, it does require trimming as the expansion will push the foam past the face of your studs.
2. Blanket Insulation
On a cold winter’s night, to stay warm, you might choose to grab a sweatshirt and a blanket. You can use the same principle for insulating your shipping container by using what’s called blanket insulation.
It comes in pre-cut lengths to fit typical wall heights and rolls (long rolled-up pieces that must be cut to length during installation). Blanket insulation is “fluffy,” compressible, and not self-supporting. It’s like your favorite blanket, except thicker and made of different materials. Blanket insulation is designed to be fastened in the cavities between studs and uses the studs as support so it will remain rigid and in place.
Varieties of blanket insulation include:
- Fiberglass Insulation: This is made from superheated sand or recycled glass spun into thin fibers. This is the most common type of cheap wall insulation in Western countries.
- Slag Wool, Mineral Wool, and Rock Wool Insulation: This is similar to fiberglass, but made from minerals and ceramics, or from ‘slag,’ a by-product of metal production.
- Sheep Wool Insulation: This insulation is made from sheep's sheared wool.
- Cotton or Denim Insulation: This is made from cotton, often with a blue-ish color because much of it is sourced from recycled denim or blue jeans.
The advantages of blanket insulation are that it is one of the cheapest options and is very easy to install – all you need is a stapler to fasten it to the studs.
3. Loose-Fill Insulation
This type of insulation is based on applying small chunks of insulation into a wall cavity. These insulators generally require complete wall cavity containment before application, or you’ll end up with a pile on the floor.
Three kinds of materials include:
- Cellulose Insulation: Made from recycled paper products that are shredded, then blown in by a machine.
- Loose-Fill Fiberglass Insulation: Similar to fiberglass batts, but less dense and not tightly bound so the machine can blow in it.
- Vermiculite Insulation and Perlite Insulation: These minerals have been heated and expanded like popcorn, making a natural foam pellet that can be added to wall cavities.
4. Expanded Foam Insulation
Expanded foam is manufactured offsite into large boards and insulation panels that are pre-sized for typical wall heights. These insulation panels are self-supporting. You’ll need to cut holes in the panels for things like doors and windows.
Expanded foam installation is easy – attach it to the studs or glue it right to the shipping container. Some varieties are molded to match a shipping container wall's corrugations to avoid large air gaps in these corrugated areas.
There are several types of expanded foam insulation:
- Open Cell Polyurethane Foam Insulation: These open-cell foam cells are not as dense and are filled with air, which gives the insulation a spongy texture.
- Closed Cell Polyurethane Foam Insulation: The ‘blowing agent’ fills the tiny microscopic cells with a gas other than air with better heat conduction properties, increasing the R-value of the foam.
- Extruded Polystyrene Foam Insulation: This is composed of small plastic beads fused together into a closed-cell foam. It’s the white foam you’d see in coffee cups.
- Expanded Polystyrene Foam Insulation: This insulation begins as a molten material pressed out of a form into closed-cell foam sheets.
- Polyisocyanurate (Polyiso): Similar to polyurethane, but more rigid.
5. Living Roof
During the warmer months, a living roof can reduce indoor temperatures by up to 8 percent, however it isn’t a replacement for proper insulation.
There are many insulation methods to choose from, and it all depends on your budget, skill level, and insulation needs. You could even use a combination of insulation methods to achieve your results. One way or another, it's good to know that insulating your shipping container is important, and count on that cost and time commitment when making a purchasing decision.