View Full Version : footings and insulation for shipping container

jim davies
07-12-2007, 01:55 AM
Just going through the adventure of pricing a used shipping container. Prices vary from $1200 to $5000 with shipping charges going the opposite way.

Anyone have any ideas/experience with putting these units on concrete pads? I'm thinking in terms of four corner poured concrete footings, say 18 inches square and 8-10 inches deep, sitting on clean gravel. Strong enough? Also, the prices quoted by can suppliers for sprayed on insulation inside is a bit spendy...about the price of the container. Is $2-3000 a reasonable amount? I once leased a metal shop that had spray on foam insulation, white with a yellow topcoat of some kind. Worked well as insulation.

07-12-2007, 04:32 AM
My dad has such a container on his property. It gets pretty hot and stuffy in there depending on sun and weather. He was thinking about putting a roof over it and extending the roof 3 ft off one side, and 8 ft off the other. The roof would be open all around for air movement. He would gain storage space on the roof of the container, some covered area for outdoor machines (his wood mill) and keep it cooler in summer, warmer in winter. He doesn't like the doors being on the end of it, he'd rather have one on the side, or at least add one on the side, under the 8 ft overhanging roof. He was thinking of cutting some holes near the top and putting in bug screens. They are dark, very dark, with the doors closed. :) They are very secure and it would be easy to weld on a lock protection box to foil the bolt cutter and sledge hammer ass-----, er, aficionados.

I think with the insulation, you'd want to make sure the metal can't condense moisture. The spray on would work for that. I don't recall if these are double walled or not- you might want to consider welding in some attachment points is there's to be a solid bench or cabinets installed- or a lathe or mill- it might make sense to take advantage of the structural strength of the container for things like that. If it's single walled, you likely wouldn't want any bolts going through the sides to hold things- that could be rust spots waiting to happen.

07-12-2007, 10:11 AM
I don't think would worry at all about footings for one,unless you aresetting it close to and attaching it to an existing building. A stone base that will drain,and let it do it's own thing.

I don't know if they are double walled or not. If they are, you could consider getting rigid foam insulation that has OSB on one face. Roofers use this often for commercial buildings. Easy to cut and fit, screw in place, and you are done.

Herm Williams
07-12-2007, 02:47 PM
Another idea would be a refrigerated truck trailer, remove the axel,and landing gear, set it on railroad ties. It would be more work getting it setup but in the long run would be a better shop. They are generelly cheaper to buy than a container.

07-12-2007, 03:36 PM
I can speak a little about this as I have three containers for storage on my place.
The first was a 24x8 purchased from a container Co. that added a roof and a plywood floor, I have had it about 10 years with No problems. it does not sweat at all.
The second was as Herm said a 40' refrigerated semi that I cut the running gear off and set on the ground. No sweating there either and it seems to keep the stored items much cleaner.
The last was a 40' shipping container they are made for stacking and if you do not put a roof of some type over it figure on it leaking within 6-8 years.
Also It sweats very badly I had to add a couple roof venilators, and a couple vents on the sides.
What I have learned from this I would again buy a 40' but I would put some kind of rounded light sheet metal roof over the top of it.
The downside of the semi trailers is once you cut the running gear off that pretty much is where it is going to live! The other two can be moved with a phone call to the container folks, or some trash delivery trucks with slide on
Setting them on gravel is ok but dirt, the squirrels will push dirt up on the sides than you will get a rusted out hole. Dont ask.
Hope this helps

07-12-2007, 04:31 PM
If this is for a shop, I have no firsthand experience, but do have a friend who temporarily has his shop in one. It sweated so badley a couple of winters ago when they had a big ice storm that it poured water on top of his Bridgeport mill...ruining the spindle bearings. Everything else was greasy enough to avoid disaster. Insulation would likely take care of the sweating but would make finding any leaks a real bear...and they will eventually leak with a flat roof.

I would be tempted to build walls inside. It would give you a surface to screw shelves etc. into, and provide space for much less costly insulation. You would loose 7" in width (for 2x4 walls).

I would agree that setting it on packed gravel would be plenty adequate. If you wanted to set it on treated 6x6's to allow space underneath that might come in handy later.

Worst case scenario by those numbers, you are looking at $5k+ for the box and several thousand for insulation and gravel etc. That puts you up close to the cost for a garage kit from Menards or some place like that.


07-12-2007, 05:30 PM
the menards cost break is what made me hold off on picking one up a while ago.

Figured I could get a kit that was better laid out for shop use, then insulate and modify to suit. I like the idea of dropping off a ready to use shed/shop, but to me the layout wouldn't be as good as I'd like.

Also, a couple yard barns can be thrown together to provide plenty of space for a few hundred each and don't require permits or listening to the neighbors complain about an eyesore.

Though I think a 20' shipping container could have a gambrel roof built over it for camoflage and be made to look pretty sweet, plus provide a better sealing option for installing other doors/windows.


07-12-2007, 05:37 PM
Another idea would be a refrigerated truck trailer, remove the axel,and landing gear, set it on railroad ties. It would be more work getting it setup but in the long run would be a better shop. They are generelly cheaper to buy than a container.

Thats what my bother has outside his shop for storage. They do make a nice outbuilding.

07-12-2007, 05:44 PM
Storage containers or trailers run the gamut from "just barely a shady spot" to "almost nice enough to live in".

I'm not exactly sure of your intended purpose, but if it is just going to be storage then your only concern would be keeping it dry inside. On the other hand if you want to use it for a shop then you will require something along the lines of what Herm Williams suggested, a reefer van. The extra insulation and build quality will be worth the extra price. You will also want to go to a little extra effort to plant it securely in at least six places on pedestals that go below the frost line. This will make for a much more solid feeling underfoot, nothing worse than the whole place shaking every time you take a couple of steps.

In either case I would leave the landing gear and running gear in place. This will leave more doors open to you in the future. To dress it up put some skirting around the trailer, not only will it look better than just resting it on blocks, but it will also be warmer in the winter.

I believe you are in Canada, so here is a representative example of what a storage trailer would go for, bare in mind a used reefer in nice shape will go for considerably more.


07-12-2007, 06:13 PM
If I was doing it, I would do it this way ..

Dig out to a depth of 1 foot .....area slightly bigger than the container.
put in inch diameter gravel ...........will take about 3 tons I would imagine .......

Place 4x9x18 inch concrete blocks on top of the gravel.....spaced four wide on the width ,............and every two foot down the length ...

Level all blocks with each over ...removing gravel and replacing gravel under the blocks.....(well not quite level... see below)

This will give good drainage and air circulation ...........the container at the spars will be four inches higher than the surrounding area ..

It will be completely dry underneath ...if you dig a channel from the ditch to a lower area ..fill channel with same gravel.

A container placed over soil will rot badly ......and have a permanent damp floor.

If done right, you will be able to place machines in it that weigh over a ton each

These containers are air tight, so also recommend putting a ventilator in the roof ......the type that vans have with spinning wind operated fan ...

and a couple of vents in the side six inches from the bottom........or the whole thing will sweat inside.

There is also nothing to stop water pooling on the roof....so recommend that you have the container pitched front to back at about 2 inches drop along it entire length ...or cover the whole roof in molten tar.

Some containers can be found, that are insulated .

all the best...mark

07-13-2007, 03:32 AM
I have one but I had the concrete pad from an old garage to put it on so i didn't have to make a foundation...I'm also in California and don't get much corrosion issues so mine is un-insulated. It is insolated though! LOL. It's under a tree for shade but is pretty uncomfortable in the summer. It's also illegal in my city (in case you live in a municipality), going on 6 years though now at the back of my property hidden from view by a wooden fence and large citrus tree trimmed right at the fence line. I have the sides lined with peg board flush against the wall...which allows you to insert pegs in the areas corrosponding to the recesses in the corrugation. So far it's been a lifesaver as far as security, storage, and letting me satisfy my shop jones on a property without a garage.

Just don't do anything dumb in there...as Forrest pointed out in another post some time ago it would be a nasty place to be stuck in a fire or something...

07-13-2007, 08:41 AM
I'm not really sure about the current price for these, but if they could be had for around 1K, it would make a good basis for a shop/shed/whatever.

You could even consider setting two side-by-side, and have a ready-made 16x40 frame. Doors/openings between the two, insulate them, and I would certainly frame a roof over them.

Yes you might be able to get a garage kit for about the same money, but these sea containers are built quite strong. You've seen pictures of loaded ships, they are stacked WAY high on top of each other.

You would be limited by only your imagination.

07-13-2007, 09:36 PM
Like the stuff they use on houses,it will go up quick

07-19-2007, 12:14 AM
I have five 8' X 20' containers and have been very satisfied with them. The first one became my reloading room. I sort of framed it inside using 2 x 4 sideways. I insulated it using 4 X 8 sheets of 1/2" insulstion using 3 sheets to fill the 1 1/2" thickness of the 2X4 I paneled over this with white paneling insulated the roof and covered it with the 2x4 celing tiles. I cut and framed a hole in one door for a room air conditioner. I use a catylic heater on a medium sized propane bottle for heat. The other four containers are placed back to back in pairs with 14 ft space in between. Pads were costructed with chrushed limestone road base with 1" max rock size. The containers were set on solid concrete 4" X 16" X 16" blocks stacked 2 deep. Metal plate shims were used to level the container with a slight slope to the door. Treated the roofs with cool seal and repainted everything grey. I plan to build a roof over the four with the space in the middle becoming boat storage.

07-19-2007, 02:17 AM
I am located in the Arizona desert outside of Phoenix and have my shop in several containers of various sizes. They all sit on treated timbers. In the winter the inside temp is kept above the dew point and the machines are covered with plastic sheets so there is no sweating problem. Swamp coolers of a large size are used for cooling and it is satisfactory most of the time. Several containers have foil covered foam ceiling insulation held in place with magnets. The best size is a 10X25 unit, the extra width makes all the difference in the world. The floor in this unit has a 3/4 underlayment added to the original floor with a 3/4 plywood topping, this is one stiff floor and holds a BP, surface grinder and horizontal mill plus all kinds of machines on wheels.

10X25 before ceiling insulation:

Original 8X20 shop:

Annex shop 8X40:

I hope this helps.

07-19-2007, 04:22 AM
Dammit, now I have container envy. I sure as heck aint showing pics of mine.

07-19-2007, 10:49 AM
I worked at a place that used these containers for generator housing. We cut windows in them and insulated them for sound deading. We also added doors in different areas for access as well some even got air conditioning. Thye also added wheels and hitches to them for moveable gen sets. Ther are very durable as long as you frame out what you cut out. I have alawys thought of buying one of these and using it for storage. The price verys as to how well the container is (the more rust the cheeper).

07-19-2007, 11:15 AM
I have a 20 ft aluminum container that I have out back to hide things in. I have been very successful in just supporting it on some 4x6 pressure treated blocks on the four corners. It is my understanding it is designed to bear all the weight on the corners. I do need to get around to putting some shelving in it and make it more usable. But right now I have my canoe collection in it as I had to remove my canoe rack to build my addition. Hmm thats why I have not posted to this board for a while.

After building a shop and several sheds there is no doubt in my mind that the storage containers are the best deal in town for space. I live in an older residential neighborhood and have had no hassles. Then again my neighbor also has one :-)

07-19-2007, 04:10 PM
Thye also added wheels and hitches to them for moveable gen sets.
Could you expand on this a bit? I am considering buying three or four of these shipping containers, or the trailers w/landing gear and rear wheels for use while we develop our rural property. The sequence of development of this property will likely dictate having to move said containers 3 times until they end up at their final resting place when the house and related infrastructure is complete.

With the trailers I could likely make some sort of hitch attachment and use the tractor or bulldozer to move them around as they already have the rear wheels on them. The big disadvantage of these trailers is they are much more a pia to use because they are so far off the ground. If a person is just storing stuff in them it is not a big deal, but if one is going in and out of them on an almost daily basis or storing wheeled machinery/equipment in them they become a hassle.

The nice thing about the shipping containers is they are relatively secure, and can be set up right at ground level. The drawback is you have to call a truck every time you want them moved, and in my case the truck may or may not be able to get back into where I want to put them. I assume these things weight quite a bit so I'm not sure of the feasibility of making removable wheel sets to move them around?


07-19-2007, 05:07 PM
they welded there own design of a axle and leaf springs to the under side of the box .They used 2 sets so there were 4 tires on each box. There was a gen set inside so no one had to go in and out all they had to do was hook up the main feed outside to what ever they wanted to run. With the axles and wheels on it was only about 2 foot off the ground. They were insulated with rock wool for sound deading and fire prevention. The hitch was just a standard hitch just like on any trailer. But you are correct these things are very heavy unloaded.If i remember correctly it was about 2 ton or so with the gen set in side of coarse it depends on what gen set they wanted in them. We even built and mounted gas and oil tanks inside as well. All said and done it was a complete setup you can pull from place to place.

07-20-2007, 04:37 AM
My 8x20 says it weighs 5500 lbs...they usually have the tare weight marked on them. Heavy, but not that heavy compared to a truck or big SUV or two nice vertical mills. I guess if you were looking at the 40'ers it would be another level of immobility.

Snip> I assume these things weight quite a bit so I'm not sure of the feasibility of making removable wheel sets to move them around?<