Guide to Insulating a Shipping Container

The desire to find sustainable, innovative options for everything from homes to storage space and offices to workshops has brought modified containers to the forefront of emerging building trends. Although they might be a surprising option, shipping containers provide a ready-made structure that is both practical and customizable. Shipping container customization offers an affordable, eco-friendly option to create very workable spaces. Here we offer a simple guide to insulating a shipping container to create the ideal space for your needs.

Can You Insulate a Shipping Container?

Absolutely. Shipping containers can be insulated to meet your needs, whether it is to protect items in storage or to create a comfortable environment for working or living. Shipping container insulation can be applied both inside and out to protect you from the elements.

Because sea cans are made of steel, they are highly durable and come complete with walls, a floor and ceiling. However, the original design was intended to prevent corrosion, which requires air circulation. As a result, without insulation, heat inside the container escapes, and outside air easily comes through the steel exterior. Container insulation resolves this issue. Once you determine how you plan to use your shipping container, you can decide the best way to approach the insulation process.

Insulating a Shipping Container: Inside or Outside?

That’ s it, you have found the perfect shipping container for sale for your needs and want to insulate it. The next question is: how do you want to insulate it? Interior insulation is the go-to in most cases as it has the protection of the steel outer walls. The main concern with interior insulation is that it will take up some of your living, storage, or workspace.

If this is a problem, outside insulation might be the answer. However, it takes more work and therefore tends to be more expensive. Also, Because it is exposed to the elements, exterior insulation is more expensive to maintain and may require replacement. When creating a living or workspace, it is not uncommon to choose both.

How to Insulate the Inside of a Shipping Container

Interior shipping container insulation is applied to the walls, ceiling, and floor. Before you begin your insulation project, there are several things to consider:

Your Climate

Since insulation’s purpose is to maintain a comfortable temperature inside regardless of the weather outside, you’ll want your insulation method to manage comfort based on the local weather. Wet climates pose the most threats to your container because of their steel exterior. Water leads to rust, so your interior insulation must reduce the risk of condensation and moisture that will corrode the structure.

Vapour Barrier

Because steel “sweats,” you need to help reduce moisture and condensation. A vapour barrier solves condensation issues helping to prevent moisture from damaging your interior building materials. Spray foam tends to provide the tight seal you need and can be applied directly to the steel.

Layout

When it comes to insulation, the more surface area you have, such as internal walls, the more complicated the insulation process becomes. In most cases, we recommend sticking to the existing footprint of your shipping container to reduce surface area.

Heating or Cooling

The steel of the container creates radiant heat that has to be controlled in the summer, but that can also come in handy in the winter. A radiant barrier helps reflect radiant heat from the outside of the structure to keep the container comfortable even on the hottest days of the year. You have to decide if your container should be heated or cooled to determine the thickness and type of insulation you need.

Eco-Friendly Materials

A benefit of using a storage container is that it provides a very environmentally friendly space. Because of this, you might be more concerned about using eco-friendly materials for insulation. It’s actually quite common to use age-old techniques as well as renewable fibers such as cotton and wool for insulation. Other recycled materials include cork and paper-based cellulose insulation. However, these materials contain flame-retardant chemicals, so they might not be as eco-friendly as you might think. Many modified shipping container owners install living roofs as part of their eco-friendly insulation plan.

Types of Interior Shipping Container Insulation

The most common types of interior insulation for shipping containers include:

Styrofoam Insulation

Made of polystyrene, Styrofoam is the most cost-effective insulation, ideal for simple installation. It doesn’t require the build-out of stud walls as the ready-made panels are simply glued to the walls. However, it also has the lowest R-value of just 4. This makes it the best solution if you only plan to use your container for storage or limited work, such as a workshop. It has a life of about 50 years, so you also won’t have to worry about replacement any time soon.

Batt Insulation

This pink insulation is made of strands of fiberglass, mineral wool, or plastic fibers. If you plan to use your container as your full-time office, this is the best choice. However, it does require wood framing installation. Although the insulation is affordable, the installation process does make it more expensive than Styrofoam. The framing and layer of drywall or plywood required over top of the insulation add up. However, if you plan to use your container as a shipping container office, this is the best option to maintain a comfortable temperature. Batt insulation has an R-value ranging from 13 to 19 and will last up to 100 years.

Spray Foam Insulation

Spray foam does not come in a solid form and requires a technician to use special equipment to spray it on the interior surfaces. The foam expands and hardens as it sets, creating a completely water-resistant, finished product. It doesn’t require framing, so if you have a storage space or workshop where aesthetics isn’t important, you can save money and leave it uncovered. It has a lifespan of 80 years and an R-value of 6 per inch of foam applied.

If you plan to use it as an office or a space such as a mobile boutique or event stall, it makes sense to invest in the finish-out. You’ll reap several benefits over other types of insulation, including reduced external noise, no settling, and resistance to bacteria, mold and fungus. Because of this, it is also ideal for storing sensitive papers and documents as well as expensive equipment. Keep in mind it is the most expensive insulation, whether you finish it out or not.

Blown Insulation

Blown-in insulation is different from spray foam as it consists of loose solid materials like fiberglass or cellulose. The materials are “blown-in,” which means there is a chance loose, tiny particles can remain in the air after installation. Another issue is that the loose materials settle, which means you might need to “top it up” in just a few years. The R-value is 4.2 per inch of insulation.

Mineral Wool Insulation

Also known as rock wool and slag wool, this type of insulation is ideal when you want a non-flammable insulation option. It is more expensive because it requires steel framing for non-flammable structures. It has a high R-value of 13 when used on walls and 26 on the ceiling. As a result, it is very good at reducing external noise. It also repels water and is expected to last a lifetime.

How to Insulate a Shipping Container from the Outside

Exterior shipping container insulation can be applied even if you have the interior insulated. It works in hand with a cladding which can include:

Wood Siding

Wood is more popular for container homes. It can last for decades but also tends to be more high maintenance than metal or vinyl. Wood expands with heat, so keep this in mind if your container won’t get a lot of shade. It is installed with your choice of insulation. It also tends to be the most expensive option. When replacing old wood siding, it is biodegradable, helping to reduce your carbon footprint. It will rot in very moist climates, and it also requires regular maintenance for the stain or paint.

Vinyl Siding

This is a low-maintenance, long-lasting option. It is very affordable compared to wood and comes in a wide variety of colours and textures. The colour is baked in, so it never requires repainting. As with wood, it can be combined with your choice of insulation. It’s also easier to install than wood, so costs less. It is more prone to trap moisture beneath the planks, which can lead to rust and corrosion. However, when installed properly, it should last for several decades.

Metal Siding

If you want a more industrial look, metal works well. However, in that case, it makes more sense to choose interior insulation and refinish the existing steel exterior to save money. You can create an interesting look with metals such as copper, which will develop a patina over time. Metal siding is low maintenance and resistant to mold and moisture. Of the three options, it is also the most durable and will stand up to Canadian weather well. Metal siding also reflects the sun, making it more comfortable in the summer, although it is also quite expensive.

Source: Poteet Architects

Green/Living Roof

Green or “living” roofs act as a natural insulator, keeping the container warm in the winter and cool in the summer. Plants and flowers create an interesting design, and you can add stairs leading up to the roof to create a calming spot to relax. The system can be expensive, but it serves many practical purposes, including storing water and creating a natural habitat for bees and butterflies. This makes it very eco-friendly.

Make Your Container a Comfortable Place

As you can see, there are many ways to insulate a shipping container and we hope this guide has helped you understand the few options available on the market. Whether you want to insulate your container for a home office, a workshop, or for your commercial needs, make sure that you are well informed about the options available and understand the pros and cons of each.

Conterm can modify new shipping containers  or used shipping containers to meet your specific needs. In addition to insulation, our modification options include adding doors, windows, electrical and more. Visit our Container Modifications page to have a better idea of all the modifications we can do for you.