Container Home Insulation
How to Insulate a Shipping Container Home
Regardless of where you are building or buying, insulation is one of the most important considerations in finishing out the interior of your container home. Whether you live in a hot climate, cold climate or temperate one, a modest investment in high-quality insulation for your shipping containers can easily pay for itself ten times over in energy cost savings.
In more extreme climates, proper insulation can literally spell the difference between living in comfort and a container home that’s unlivable. At Stackhouse, the intense Texas heat is something we consider in every one of our builds. From the orientation of our containers to the style and application of our insulation recomendations, we’ve got building energy-efficient container homes down to a science. If you still have questions after reading this container home insulation guide, don’t hesitate to reach out to one of our container home experts today.
The Best Container Home Insulation
All things considered, our favorite style of insulation for container homes is closed-cell spray foam. We particularly like Icynene C-200 due to the fact that it is known for very little VOC off-gassing and even expansion. While there are many other spray foam alternatives that work for container home insulation, few hold a candle to the efficiency, safety, and effectiveness of Icynene C-200.
Admittedly, Icyneen is far from the cheapest spray foam available and there are a few lower-cost alternatives that will also insulate your container home pretty well. If you are considering alternative spray foam insulation, make sure it is closed cell and low VOC/off gassing.
The reason we recommend closed cell foam starts with the fact that it has a much a higher R-value than open celled foam. In short, the higher the R-value of your container home insulation, the better it will be at keeping heat out. Furthermore, closed cell foam is much better at stopping water and air from getting into a container. Considering the costly damage that can be caused by water intrusion in the form of corrosion, closed-cell foam is practically a no-brainer. To maximize energy efficiency and weather protection, many of our container home clients opt to apply a layer of spray foam to both exterior and interior walls, typically sandwiched between exterior siding and drywall.
If you’re living in a temperate climate and wanting to maximize your interior living space, a well-applied exterior spray foam coating under the exterior siding of your container home may suffice.
Other Container House Insulation Options
At Stackhouse, we understand the importance of staying underbudget on your container home build. If spray foam insulation seems out of the realm of possibility for your budget, there are a number of other viable alternatives that will still get the job done.
Expanded Foam Insulation
Similar to spray foam in composition, expanded foam insulation is basically just spray foam sold in pre-fabricated sheets.
Typically sold as large, pre-sized sheets and panels, pre-manufactured expanded foam is usually found in lengths that match the heights of a standard 8 foot ceiling. Also commonly-available in a 48’’ length, these sheets of expanded foam are often sold with mylar backing adhered to one side to maximize their effectiveness.
Expanded foam is easy to cut with a straight razor and can typically be laid like drywall in the gaps between the metal studs along a container wall. Similar to drywall, the gaps between sheets of expanded foam are typically sealed with a mylar tape that lessens the possibility of air and energy escaping after installation.
Unfortunately, this type of container insulation is prone to deteriorating R-value over time and a small user error in installation can drastically reduce its ability to insulate. Expanded foam board is also unable to create a weatherproof seal like closed cell spray foam, as the seams between pieces are much more likely to let water in under certain circumstances.
Regardless of its shortcomings, expanded foam insulation is the highest R-value container home insulation alternative available outside of spray foam and is definitely worthy of consideration for a budget build.
The most commonly-available varieties of expanded foam insulation are as follows:
• Open Cell Polyurethane Foam (PU):
Lower- R-Value open cell foam with air filling open spaces. Open Cell Polyurethane Foam is less dense than closed celled varieties and exhibits a ‘spongier’ feel
• Closed Cell Polyurethane Foam (PU):
Closed Cell Polyurethane is the closest you can get to the insulating effectiveness of a spray foam in a pre-fabricated form. Its R-value is higher due to the addition of a ‘blowing agent’ that replaces the air in the open cell foam with another gas with better heat conduction efficiency.
• Polyisocyanurate (Polyiso):
Similar in composition to Polyurethane Foam but manufactured with a different chemical reaction that makes it more rigid and thermally-resistant
• Extruded Polystyrene Foam (EPS):
Sheets of small plastic beads that have been fused together to form a uniform, rectangular piece.
• Expanded Polystyrene Foam (XPS):
Melted plastic material that’s been molded into rectangular sheets.
If you’re uninterested in insulating your container home with foam, there are still a number of other options available for you to consider.
Insulating with Wool
One of the more popular and cost-effective container home foam insulation alternatives, wool insulation also offers the advantages of being relatively eco-friendly. Because wool from sheep is both renewable and abundant, some earth-conscious container home builders opt to use it to insulate their houses in the interest of sustainability.
While the 3.5 R-value of wool insulation is only about half as effective as closed-cell spray foam (6.7 R-value), it’s actually pretty close to the effectiveness of open cell foam alternatives (average 3.7 R-value). One additional benefit of wool insulation for container homes is the fact that the lanolin found in sheep wool is naturally flame retardant.
Along the same lines of the eco-friendliness of wool insulation, some container home builders opt to insulate their houses with denim from recycled jeans. While denim is not renewable in the same way as naturally-occurring insulation like wool, the repurposing of existing material to insulate your container home definitely lowers your net environmental impact.
Also similar to wool in its ability to insulate, well-made denim insulation can provide your container home an R-value around 3.5—impressively close to the efficiency of open cell foam.
Unfortunately, insulating your container house with denim does come with a few downsides. One disadvantage of denim insulation in comparison to wool is the fact that denim is not naturally flame retardant. To help mitigate fire risk, most denim insulation manufacturers treat their insulation with a flame retardant like boric acid before selling it to a container home builder.
Another disadvantage of using denim to insulate your container house is the fact that it requires the insulation of a vapor barrier to maintain its insulation properties long term. Container home builders who fail to plan for this will find denim loses a considerable amount of its ability to insulate when it becomes wet. This is an especially important consideration in climates that see annual snow or regular rain.
Insulating a Container Home with Cork
Coming at an average 3.0 R-value per square inch, cork is another natural shipping container home foam insulation alternative worth looking into. Similarly renewable to wool, cork has the added eco-friendly advantage of natural biodegradability. All things considered, cork insulation is a solid option for a container home builder looking to minimize the ecological impact of their build.
Due to the fact that cork trees do not need to be cut down to harvest their cork, and the fact that trees help offset carbon emissions by nature, this container home insulation alternative is actually considered carbon negative.
Another advantage of insulating your container house with cork is its natural ability to insulate against noise. This is especially helpful for container home builders who are planning on building in urban environments and those who really prioritize a quiet living space.
Is Container Home Insulation Really That Important?
Depending on the climate you live in, insulating your container home may very well be the most important decision you make as an owner. Not only does insulation help keep heating and cooling costs down in the winter and summer months, it can spell the difference between a comfortable container home and the feeling of living in an oven or a freezer.
Because the steel that comprises the exterior walls of a shipping container is such an efficient energy-transfer medium, failure to insulate a shipping container home can practically make your container home uninhabitable.
As a shipping container home builder in Texas, Stackhouse strongly urges all of our clients to insulate with high quality closed-cell foam to avoid trouble during the sweltering Texas summers. While closed cell spray foam is one of the more expensive ways to insulate a container home, the upfront cost can end up being exponentially less than the energy costs incurred trying to keep living spaces comfortable during the hotter days of summer and colder days of winter.
While some people are able to do without container home insulation in more mild or temperate climates, recent global shifts in climate patterns make a strong argument for the better safe than sorry approach. The last thing you want is to end up with a container home that’s unlivable because you skipped out on insulation!
What is the Best Shipping Container Home Insulation?
At the end of the day, the best shipping container home insulation material is the one that best fits into your budget, wants, and needs. Just because we prefer to use closed-cell spray foam for our container home builds at Stackhouse, doesn’t mean you have to follow suit.
All things considered, the most important part of choosing insulation for a shipping container home boils down to your personal situation. If you’re still having trouble deciding on your container home insulation, don’t hesitate to reach out to a StackHouse container house expert today.