How to Select a Roof For Your Shipping Container Home

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Updated On: December 20, 2019

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The choice of whether to add a roof to your container or not is made up of both personal preference for the style and also the cost. Clearly, not roofing your container will save you money initially. However, in the long run installing a roof and insulating it could save you money in energy bills.

Because hot air rises, the majority of the heat lost in your home will be due to it escaping through your roof.

When making this decision, consider that having a roof allows you to insulate inside of the roof which will help to maintain and keep the inside temperature consistent. Having a roof with an overhang keeps the rain from running down onto your windows and removes the need for a drip bar above the windows.

Different Roof Styles

Shed

A shed style roof, shown below, is essentially a sloped roof. The advantages of using a shed style roof are that it is extremely cheap and very simple to build. A roof like this can be made and installed in a couple of days. The long, sloping roof also lends itself well to solar panels.

Shed Style Shipping Container Roof

To install a shed style roof on your shipping container, weld right angled steel plates across the length of the shipping container on both sides. On each side of the container roof attach a wooden beam into the steel plates. Screw the trusses into this beam. Now, the roof’s basic structure is starting to take shape. Attach purlins or steel bars for structural support across the trusses to complete the roof’s structure. For this step, you can just add 20 foot long purlins onto the trusses and you’re done. Next, your trusses need bracing to protect you again the wind.

This is when you will depend on your structural engineer for specifics. This professional engineer will be able to advise you about the exact load bearing requirements needed for your roof. This figure varies regionally as it takes into account natural stresses imposed on your roof such as rain, wind and snow loads.

To cover your roof, you can use either shingles, galvanized metal sheets or coated steel sheets. Coated steel will be the most durable, however galvanized metal sheets are very easy to fit and are also quite durable.

Shed Style Shipping Container Roof Truss

The final stage is ensuring your roof has sufficient ventilation. To do this your trusses should overhang the container as shown below. Attach a fascia and soffit board underneath your trusses. The soffit board should have at least an inch air gap in the middle of it, covered with wire mesh which allows air to flow in and out of the roof.

Shed Style Shipping Container Roof Ventilation

Make sure you allow for ventilation at the gable ends. Do this by simply cutting slots out of the steel using a disc cutter. This will allow air to pass through the roof and avoid heat traps and condensation which causes rust.

Gable

Your next option is to use a gable styled roof as shown below. A gable styled roof is what most people imagine when they think of a traditional home. It has the distinguishing triangle look. The advantage of using a gable roof is that it has a sloped roof which provides great water drainage. This makes it less likely to leak and helps extend the lifespan of your roof. It is popular because it also provides more ceiling space than other roof styles.

Gable Style Shipping Container Roof

The construction of this roof is similar to the stages detailed above for installing a shed style roof.

To install a gable style roof on your shipping container, weld right angled steel plates across the length of the shipping container on both sides. On each side of the container roof attach a wooden beam into the steel plates. Next, screw your trusses into these wooden beams and the roof’s basic structure is starting to take shape. Now attach purlins across the trusses to complete the roof’s structure.

Like the shed style roof, you can either use shingles, galvanized metal sheets, or coated steel sheets.

Gable Style Shipping Container Roof Truss

Now make sure the roof has sufficient ventilation. Trusses should overhang the container as shown below. You can then attach a fascia and soffit board underneath your trusses. The soffit board should have at least an inch air gap in the middle of it, covered with wire mesh which allows air to flow in and out of the roof.

Gable Style Shipping Container Roof Ventilation

 

Flat

A flat roof, which the shipping container already has, can be adequate for some people’s needs. Although it’s clearly cheaper not to roof your shipping container, this does leave you susceptible to water pooling on the roof.

Flat Style Shipping Container Roof

If you decide not to roof your containers, a quick safety barrier should be installed. Lay a tarpaulin sheet onto the roof of the container and overlay this with rolls of asphalt. This will provide you with a layer of defense between the dampness and the container’s roof.

Importance of Having a Structural Engineer

Whichever roof type you choose, make sure to work with your structural engineer to calculate the load bearing requirements of your roof.

To do this they will calculate the dead, live, and transient load of your roof.

  • The dead load includes the combined weight of all the materials which were used to build the roof (i.e. trusses, purlins, roof tiles).
  • The live load is the weight of any equipment and people who work to install the roof.
  • The transient load is all of the natural stresses placed upon the roof such as rain, wind, and snow.

The load-bearing capacity of your roof is the total weight the structure of the roof can carry without the roof collapsing.

Each local area will face different challenges. For instance, certain areas prone to high winds will need roofs with additional bracing for the trusses. Warmer climates, with a light breeze, don’t need a roof with very strong structural capability but need it more for the insulation benefits.

All of the roof types need to have adequate ventilation to prevent condensation.

Let us know your ideas about roofing for container homes in the comments section below.

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21 Responses

  1. Hi,

    Can anyone that has put a patio on top of a container house provide some insight into what it entailed?

    Thanks,
    Bill

    1. Not sure you’ll get a ton of responses in the comments section here. In general, you’ll want to build a structural frame that supports the load of the patio and transfers it into the top side rails of the container. I’d recommend looking through a few of the homes in our container project database (https://www.discovercontainers.com/projects/) for inspiration. For instance, the Hinkle House (https://www.discovercontainers.com/projects/hinckle-container-house/) is a good example with a porch that has some good pictures.

  2. Hi,
    I love your website!! My husband and I have discussed the possibility of building a large container home (2200+ sq ft), I noticed that you have not had questions on how to build a container home on top of a basement foundation and you addressed several roof styles, but what about a mansard roof? Would really be interested in finding out how to build a container home with those additional considerations. Right now I live in the metro Atlanta area and I hate the throw-up houses here that they want to charge an arm and 2 legs for, but I’m originally from Philadelphia

    Thanks so much for your website, it’s a wealth of info!

    1. Glad you’re enjoying the website! Our container foundation article (https://www.discovercontainers.com/shipping-container-home-foundation-types/) discusses perimeter foundations, which are essentially the same as a basement. You’d just make the perimeter walls taller and start them deeper underground. Because containers are quite strong, you typically don’t need much, if any, support along their length which can give a lot of open space in a basement.

      Mansard roofs are not very popular in general, especially so with the type of modern/industrial architecture that you typically see with containers. But, there’s really no reason why you couldn’t build a mansard roof if you wanted to. There wouldn’t really be anything container-specific about it, you’d take most of the same steps if you were building a mansard roof on top of another kind of building. You would need to decide if you want to build the frame from wood or steel, and determine how to fasten everything together. But in the grand scheme of building a container home, this is a pretty small issue to solve for. In return, you’d get a very unique container home and a bonus second story area. Hope you’ll keep us posted if you decide to move forward.

  3. I love your site and I am absolutely consumed by me infatuation with container structures.. Can you please explain the pros and cons of a live roof and how it can be done without creating a water problem. I want to turn each flat roof surface into garden and or deck space to utilize every square ft of flat surface to get the most out of my structure while keeping the overall footprint as small as possible. I was thinking of collecting all the rain water to irrigation well. Thank you.

    1. Jonathan,

      It’s a good question that might lead to an article in the future. We’ve seen a handful of green roof projects in the past, and they are pretty interesting. They give you done additional insulation, improve the air quality, and make your home look inviting, but can be somewhat complex, expensive, and require some structural enhancements. The metal roof of a shipping container is not strong enough to support a green roof, you would need to either add additional support elements from underneath or build a secondary support structure on top. Most green roof systems contain several layers of waterproofing, drainage, and growing medium. There are also some modular systems that use plastic trays which are pretty neat. The only thing really unique about building a green roof on a container is that you need to ensure you can support it structurally. Otherwise, most of the same rules and guidelines apply from green roofs on any other type of building.

  4. Hey just stumbled across this site and I love it! I’ve been looking to build a multi-container home for years now but I live in Northern Indiana where it can tend to be a bit random on the weather we get hot humid summers, below 0 winters no snow or 5 feet of it, hail, wind etc. I’ve been considering a slightly pitched sealed rubber roof for it’s R value, moisture blocking and semi versatile design. Any advice on a better alternative for my climate that still lets me keep the Flat look I enjoy?

    1. Glad you found us! Your proposed roof idea sounds fine. The biggest issue will be the potential snow load. If the roof isn’t sloped enough to let accumulation fall off, you need to ensure your roof is structurally designed to handle the weight of several feet of snow. Also keep in mind where you want to place your insulation: if you want to insulate above the ceiling of the container but below the roof, ensure you have enough vertical clearance in your roof design.

  5. Hi, thanks for all the info. It’s a big help. I was wondering if it is possible to reinforce a 2 container high by 2 container wide with an a frame attic with columns and maybe steel beams? I live in SD, lots of snow.

    1. Yes, you could place A-frame trusses on top of a two-container-wide home. If you’re doing substantial modifications to the load-bearing walls of the containers underneath, you may need some structural additions there as well.

  6. Nice site. For a common 8 or 10 by 40 ft container snow load is not a consideration unless you live somewhere where there are huge accumulations. But what is happening is people want to use 2 containers and put trusses spanning 30 or 40 ft across from one container edge to the other. They must be really careful in that the weight of snow(live load) and the weight of the trusses and roof material(dead load) will exceed the container walls safe load carrying capacity. The load carrying capacity of the side wall is the Payload X 0.6. Even for a single 10 ft wide container a roof with eaves could be 12ft wide or more giving a total roof area of 480 sq. ft. If the snow load was 150 lbs/sq-ft the container would be at its crushing strength. This may result in damage or injury. You should make a note about this in case anyone wants to have a container home in say tahoe or up in the mountains of the north west or Alaska.

    1. Thanks for sharing! What’s most important is understanding that every situation is different and if you have some unique circumstances (large snow loads, large roof, unconventional design, etc.) it deserves professional engineering analysis. Foundation type, container wall modifications, roof style…these all affect the structural capacity of a container building. And with so many potential variables at play, we can’t give a one-size-fits-all recommendation. With snow, you’d need several feet of accumulation to get over 100 lbs/SF, so the simplest solution for this specific situation is keeping heavy snow cover off of your roof. We’ll consider expanding on this article in the coming months to include more guidance on some of these situations. THanks again.

  7. Hi Dave,

    I am purchasing a container home and trying to find out the load capacity of the roof. It is a multi-level home with a flat roof covered with astro turf and metal railings around it because the views from up top are amazing. I don’t know exactly what was used to build the roof, is there a way I can find the weight limit of the roof?

    Thank you!

    1. Per ISO 1496, a 600mm by 300mm section of the roof must be able to withstand 200kg. However, it will almost always temporarily dent in while that load is applied. The short answer is, you’ll need substantial structural reinforcement to make a container roof into a deck. The roof of a shipping container is only designed to keep out the weather, it is not structural.

  8. Hi, kudos for the great info you have put together. I am considering putting up a container home in Ghana where the weather is usually hot. I am looking at using Aluminium foil with bitumen for the roof. This is to provide some insulation as well. Do you think this is a good idea. This will be done on a flat roof. Thank you.

    1. Thanks for reading! Not sure what order you’re planning to place these materials in…If aluminum foil is the top layer, that will certainly be reflective, but maybe not that durable. If you haven’t already, please check out these two relevant articles that may help you think through some alternative approaches:
      https://www.discovercontainers.com/essential-knowledge-about-heat-transfer-in-shipping-container-buildings/ and https://www.discovercontainers.com/cool-roof-coatings/
      And feel free to email us via the Contact page if you have any additional questions.

  9. I am build8ng a home with a 40 ft reefer container. Have no experience, learning and researching as i go along. Thanks for this

    1. Thanks for reading, and be sure to check out more of our informative articles on other container home building topics!

  10. Tom and friends,

    I already have a home but due to life happening i have a need to expand it. It is a conventional 2 story front walkout built into a hillside in suburban Minneapolis, Minnesota USA, my bizarre idea is to put a 40 ft container or 2 20ft ones adjacent to and connecting them to the existing structure. So as to expand the size of the master suite and/or perhaps to put in a new kitchen allowing the demo of the current 80’s monstrosity to expand the living/ dining area in the space said monstrosity occupies. Is this even possible? The other bizarre idea i had is to add a second one on top of it to maybe make a 2nd story inlaw suite for my step daughter… but all I see here are independent buildings can these be used to expand/extend existing woodframe construction. Also Are there ways to storm proof these so that they don’t act like a trailer in a windstorm?

    Love the site!

    Thanks!

    Dave

    1. Hi Dave,

      Thank you for getting in touch.

      Yes you can certainly extend a traditional home using containers.

      In terms of storm-proofing, containers are much stronger and more resilient than any trailer. Make sure they are welded to your foundation and consider using metal storm doors to cover doors and windows if you really want to be secure.

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