How to insulate a shipping container home
- By: Ashley Saunders
- August 2021
An important step when converting a shipping container into a home is insulating the inside. With the proper insulation, you can prevent condensation and ensure your new home retains heat. But you might wonder how to insulate a shipping container home.
Before adding insulation, you need to modify your shipping container by cutting holes for doors, windows and openings to make it into a liveable space and then reinforce them to ensure structural integrity.
Modifying and adding insulation to shipping containers can be the biggest costs you’ll face. And while conversion companies offer this as a service, some clients want to reduce costs and so, prefer to do it themselves.
The first huddle that many encounter is what is the best insulation material to use for the intended use. In this guide, we’ll look at a few different materials you could use as well as the basic process involved in insulating a shipping container.
By the end, you’ll know how to insulate a shipping container home and ensure you can still add utilities later!
Basics of insulating a shipping container
Adding insulation will protect against high and low temperatures. It will also prevent condensation that can increase corrosion rates and allow mould to form. Insulation also helps to reduce noise breakout, meaning you don’t disturb the neighbours.
There are several ways are available to insulate a shipping container, including adding insulation and plasterboard; or applying spray foam.
But before you start, it’s worth considering the climate of the location of your container home. For example, if your plot is in an extremely cold location or close to the sea, then you’ll need to add a thick layer of insulation.
Thankfully, the basic process for insulating a shipping container is very simple.
First, you need to build an internal frame inside your shipping container, similar to if you were building a stud wall. On one side of the frame is the metal container, the other will be the internal wall, usually made from plasterboard. The cavity is filled with insulation material.
Where should I add insulation?
As you now understand why you need to add insulation to your shipping container home, let’s consider where to add it. As giant steel boxes, there are three different ways you can insulate a container house and improve its heat retention.
One method is to cover the outer side of the container wall. While this will have little effect on the heat retention inside, adding exterior insulation will protect the shell against the effects of bad weather.
Adding exterior insulation will be more expensive than internal insulation as the area you have to cover is far greater. There’s plenty of options to choose from including wood, plaster, or even stone. Cork is another superb material that offers good thermal and acoustic insulation qualities.
If you love their industrial external look or working with a small budget, then focus on interior insulation. We’ll cover the most popular materials in a moment. A major downside of thick internal insulation is you’ll lose living space. Typically, the thickness of the partition should not exceed 10cm.
Mixture of both
You could insulate the interior and exterior of the container house. However, this is not necessarily recommended because it creates excessive temperature variations and strong instability of thermal bridges.
Should you DIY or use a professional?
Many want to DIY the entire process of converting shipping containers into a home, whether that’s due to budget constraints or because they can. That said, just because you can, doesn’t mean you should!
As adding insulation is a critical step in the build process, you may want to use a builder or specialist shipping container conversion company. It’s possible to DIY but will take you longer to insulate each wall and will involve plenty of experimentation.
On the other hand, leaving it to the professionals ensures the task is completed quickly and accurately the first time.
What insulation materials can I use in my shipping container home?
Any material with good insulating properties can be used in a shipping container home. The most commonly used insulation materials are Rockwool or Kingspan branded. Both require a timber frame to hold the insulation in place, which is then covered with plasterboards.
Another common insulation material is spray foam. Let’s explore these options and more in more depth.
Extremely cheap, Rockwool is very effective when tightly packed into cavities to ensure no air gaps or space. It’s easy to work with and allowing you to quickly insulate a shipping container.
Rockwool is ideal if you’re converting containers into an office but isn’t the best option if you’re building homes from shipping containers.
Just like with Rockwool, Kingspan insulation boards are easy to cut to size and sit behind ply or plasterboard, giving the appearance of a normal internal wall. While a popular insulation material, Kingspan (who also own Potton) is expensive.
However, a more expensive insulator allows for thinner wall cavities, maximising the internal space inside your container conversion. Good news if you’re tight on space in your container home’s floor plan.
As a popular insulator abroad and in the USA, spray foam provides a seamless vapour barrier and is quicker to apply than other methods. That said, it is a more expensive option and there are varying reports on its overall performance when used in a container home.
An industry-leading spray foam insulator is Icynene®. Designed to solve condensation and insulation issues in shipping containers, it can be applied to the inside and outside of the container.
Consider using wool or cotton to insulate your shipping container. Just like Rockwool and Kingspan, it needs to be installed in a frame and packed in tightly. However, it is very eco-friendly, making them ideal if you aim to live more sustainably.
Cork is another natural insulator that is renewable and biodegradable. Surprisingly, harvesting cork doesn’t involve cutting down the tree. Instead, the tree bark is peeled off every nine years, meaning the harvesting process is carbon negative.
Another advantage of cork is its acoustic properties. The cork forms an acoustic buffer between your home and the container’s metal walls, ensuring minimal noise reaches the outside.
In reality, you can use any material with insulating properties, opening an endless list of options that could be used when conversing a shipping container.
What to avoid when insulating shipping containers
Ideally, you should avoid conventional insulation methods unless they are corrosion-resistant or do not promote condensation.
Using materials without these qualities could result in the material’s deterioration or too much condensation inside the walls due to excess moisture, heat, or fumes.
That’s how to insulate a shipping container home
Now you have some ideas on how to insulate a shipping container home, you can attempt to convert some into a habitable dwelling.
If you’re unsure if a particular material or method will work for your project, then either pay a professional conversion to handle this part of the process or do your research and talk to as many people as possible.