I fully intended to replace the original floors in my shipping containers with new plywood, although I was not looking forward to the work involved. I had read of the chemicals used to treat the plywood floors and the potential health risks to humans, so I really didn’t think I had a choice. Everything that I had read though focused on Basileum SI-84 as the chemical of choice for plywood in shipping containers. When my containers arrived, I was surprised to find that they were treated with Radaleum FHP-60 instead of Basileum – not that I knew what Radaleum FHP-60 even was.
Container data plate
To find out what the plywood flooring has been treated with, you need to look at the container data plate. This should be attached to a door of the container, although they could be missing from containers that have been removed from service. The plate will have a section called “timber component treatment” with three parts separated by forward slashes. The first part “IM” stands for immunity, the second is the treatment chemical, and the third is the date of treatment.
The active ingredient in Basileum SI-84 is Phoxim, an organophosphate compound. Phoxim seems to be commonly used against ants and termites, and can be found under the brand name of Baythion produced by the Bayer Corporation. The active ingredient in Radaleum FHP-60 is theta-Cypermethrin, a 2nd generation synthetic pyrethroid. According to Wikipedia, Cypermethrin is found in many household ant and cockroach killers, including Raid and ant chalk.
Both Phoxim and Cypermethrin are considered moderately hazardous (Class II) by the World Health Organization. What differentiates these two chemicals for my purposes is their vapor pressures. Phoxim has a vapor pressure of 2.63 mm Hg at 20° C, while Cypermethrin has a virtually nonexistent vapor pressure of only 0.0013 mm Hg at 20° C – more than 2,000 times lower. Why is the vapor pressure important? It’s easy to encapsulate the contaminated floors of a shipping container to eliminate physical contact, but it’s very difficult to block their vapors, if present, and their subsequent inhalation.
With the walls removed between my containers, I think it’s necessary to install some kind of subfloor on top of the existing container floor. While this would provide an excellent physical barrier from the treated plywood, I wanted an additional chemical resistant barrier between me and the Cypermethrin just to be safe. I just don’t trust that Cypermethrin is the only hazardous ingredient present in the plywood – it is made in China after all.
After a lot of research, I decided to seal the plywood with epoxy. In theory, the epoxy should be both a physical and vapor barrier to the chemicals. The epoxy I chose to use was Low V from Progressive Epoxy Polymers. Progressive is not a big company, but they have a good reputation among the boat building community. They offer a wide range of high quality epoxies for a very reasonable price. Low V is a solvent free, 100% solids epoxy that they recommend for penetrating and sealing wood surfaces. The only reservation they had with me using this, or any other epoxy, is that it might not bond to the wood due to the pesticides or any oil staining. BTW, there is an absolute wealth of information about epoxies on their website – IF you can navigate through the poor design of their site.
Before applying the epoxy, I chose to solvent wash the floors with 91% isopropyl alcohol. I did this to remove any surface chemicals or oils that would prevent the epoxy from penetrating and adhering to the wood. I used about one gallon of isopropyl per container to wash the floors. Be sure to have plenty of ventilation if you attempt this, as the alcohol vapors can be strong. You will also need to choose your mop carefully, as two different mops that I tried came apart in the isopropyl in short order.
Dried epoxy on plywood floor
I applied two separate coats of epoxy to the plywood using a paint roller on an extension pole. The first/primer coat was thinned with 25% Xylene to aid in penetrating the plywood floor. The second coat was applied full strength a week later. It takes several hours to dry to the touch depending on the temperature, and after the second coat it dries to a very hard, almost wet looking smooth finish. I doubt anything of significance is going to get through that epoxy.
Additional information:
Cargo Containers – quarantine aspects and procedures
World Health Organization Classification of Pesticides by Hazard
Steve,
Thanks SOOO much for the suggestion of this site. I can hardly believe how awesome this has turned out, IMO. Mine was planned to be 4 x 40′ containers and one 40′ for a garage separated from the main building. Now that I have seen yours, I am just SOO excited to break ground. Now if we can just get through the closing on this second property… I will surely give you a heads up once we get started.
Thanks again!
Wallace
Wallace:
Thanks for the encouragement. I’m really looking forward to see how yours turn out, especially since you have an architect to design it for you. Mine is a bit more practical in appearance, at least on the outside. Please keep in touch as you move forward.
Regards.
Steve
Isn’t Xylene just as bad if not worse than Phoxim?
See: http://en.wikipedia.org/wiki/Xylene
Dave
Dave:
The important difference between the Xylene in the epoxy and the pesticides in the plywood flooring is that the Xylene does not stay in the epoxy. By the time the epoxy has fully cured, there should be no Xylene present in it at all – it will have completely evaporated. The pesticides on the other hand are persistent in the wood and are meant to stay active for many years.
If you are talking about short term exposure from Xylene during the application of the epoxy, then yes you should be careful. It should only be used with adequate ventilation and/or a proper organic vapor respirator.
I’m actually more concerned with the longer term emissions of volatile organic compounds from building materials such as OSB, spray foam insulation, and finish flooring than I am from the epoxy coating.
Regards.
Steve
Steve,
I have a question, When you cut out the interior walls did you have and flexing or sagging of the cieling once they were removed? You may have covered this already but I just found your blog today and am still reading through it. Thanks
Todd
Todd:
I spoke of this briefly in my “Foundation Plans” post. The roof is reinforced with two 6″x3″x20′ steel box beams on the seams between the containers. The beams were stitch welded (50% coverage) to the upper box beam of each container. The beams were specified by George Runkle of Runkle Consulting who specializes in container housing engineering. There has been absolutely no sagging of the upper beams with these in place. Please keep in mind that you should always consult a qualified engineer before removing any structural components of a shipping container.
The floor beams are supported underneath by two concrete piers in the center of the span. Since the floor beams just rested on the piers, it did vibrate some when walked upon initially. Most, but not all, of this was removed when the subfloor was installed. I also clamped the I-beams under the containers together with four sets of metal plates and bolts I had laying around. Both of these things seem to have tied the floors of the containers together fairly well.
Steve
Hi
reading your blog and living vicariously……quick question – did you consider a tile floor over the plywood? Easy to clean etc…..and if you have that crawl space under the house, would the vapors go that direction?
As you can tell I am neither a rocket scientist or an architect
Beth:
Thought about tile, but I really wanted a wood floor for a more cabin like feel. I also got an awesome deal on some good looking laminate. I figure I can change it out if I don’t like it and not be out too much.
In regards to the vapors, there really won’t be any. The Cypermethrin in my containers floor treatment has virtually no vapor pressure, so it should not give off any significant vapors. With the epoxy and subfloor on top, and the undercoating and spray foam on the bottom, I consider the treatment chemicals to be well encapsulated.
Hope this helps.
Steve
hello Steve I am building a container house with the exact same containers. we removed the floor sandblasted the floor joists and frame to try to remove the black undercoat. we filled the void after plumbing & electrical underground with concrete covering 4″ above seams welded 2 together. still had strong odor so we went after the caulking. removed and sandblasted residue. sprayed HardSeal on after and still smells. I scraped the interior paint and the same strong odor of mothballs!! I am thinking of sandblasting the entire interior I can’t live with this chemical. I also called Harding Container Manufacturer to get specifics on paint, caulk. The irony is I intended on a Green project. And now it’s chasing down the annoying chemicals.
Hi Mark:
Sorry to hear of your problems. You say you’re using the exact same containers – are they actually from Cherokee West Enterprises? My containers do not have a mothball odor, but there is a slight chemical odor when I open it up after being away for a couple of weeks. I personally think it’s due to residual out-gassing from the spray foam insulation as it didn’t really smell that way before. It was pretty strong right after they sprayed it, and it has weakened considerably over time, but after the windows are opened it goes away pretty quick.
If the odor is from the paint, there may be options other than sandblasting. If you are planning to insulate with spray foam (soy based in your case), a couple inches of that may effectively encapsulate the paint and odor. Another possibility would be to encapsulate the paint with a coating specifically designed for that. While I have never tried it, another container builder recommends RUSTGRIP to encapsulate the lead paint that can be found in some shipping containers. In the end, the only guaranteed way to get rid of the smell would probably be sandblasting.
Good luck and let me know how it turns out.
Steve
Hey Steve, Thanks for your quick reply!! The container manufacture is Harding Container Corp. in Long Beach of course they are manufactured in China. But the nomenclature plate looked at first glance the same, but has same wood treatment. I have 5- 40′ high cubes. I am using a product by SafeCoat called “HardSeal”. Once I can prove that it will seal the off gassing. I will coat all interior walls with this “HardSeal” and then “SuperTherm’ ceramic coating works well for condensation abatement and sound insulation some R value. And then frame steel stud walls and ceilings then insulate and sheetrock interior. Here in Sacramento,Calif. valley we have some pretty hot afternoons and this is when the vapors really get excited.
Thanks for your input and I will keep you posted and send photos when completed. Hopefully a couple of months. This project is taking all my time away from my blacksmithing.
Mark:
You may want to reconsider using SuperTherm or any other similar product. Whenever these have been tested by independent parties they have failed miserably in almost every way. I encourage you to read the following:
Insulating Paint Test – Cold Climate Housing Research Center
Insulating Paint Additive Manufacturers Exaggerate % Of Advertised Energy Cost Savings
When I was researching anti-condensation coatings the only one I found that others had success with was Mascoat Marine Insulating Paint. There’s a great discussion of this paint on the C-Brats boating forum here.
Steve
Hi Steve,
I linked to your site from Jetson Green. I’m really happy to find your thoughts about shipping container flooring, as it’s hard to get this information anywhere. We’re about to start construction on our container house (here: http://everydayishalloween.wordpress.com), and my builder has been assuring me that we can seal the floors, and I love the look, but I’ve been just a little nervous. I’m going to keep reading here…thanks for sharing your experiences.
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Thank you for this site!! I bought a 40ft hi cube last week. The poor container has several dents and rust (a few spots that are bahd) and, unfortunately, the basileum treated floor. In considering what to do with this floor, I did think about cutting the metal roof off then taking the wood floor out and turning the container upside down. I would weld the metal to the roof (or do something else for a roof/ceiling) and then take the salvaged wood flooring to make boxes with that would mount on top of the steel rafters (that were previously under the floor). I would make the boxes as deep as I had wood and then fill them up with dirt. My thoughts are that it would supply cheap insulation, the wood would not end up in the dump nor would I be inhaling any fumes from it. The floor on my container is designed to hold 67,000 lbs soooo Im sure it could hold the dirt if turned upside down. Of course I would have to put in a floor that I could actually use. IF I go this route, would I be inhaling vapors still? Do they go down or up or both?
My brother (who is less “green” thinking then I, but cheap too) is saying I could just pressure wash the floor, then paint it, then put linoleum over it……. what do you think about this approach or putting tile or cement over it? Do you think this might “encase” the fumes?
Hi Teresa:
Whatever you do, don’t cut the metal roof off as this will affect the structural integrity of the container. Turning it upside down will also not do anything to reduce the vapors from the treated plywood. Shipping containers are also not designed structurally to have dirt placed on the top or sides. If you really want to go this route, you will need to work with an engineer to make sure it’s done safely.
Paint, linoleum, tile, and even cement to some degree, are not impermeable to organic vapors. The only thing that comes close, at least that’s easily applied, is a high quality epoxy. In my opinion you have two options, replace the floor with new wood or encapsulate the existing floor with epoxy. Replacing the wood floor is always the best option, but it is difficult and expensive. Epoxy encapsulation, for my purposes at least, was an easy and cost effective that I feel is safe.
If you do choose to use epoxy, your used container will probably take a little more effort to get it right. Epoxy does not like to adhere to oil soaked wood, so pressure washing followed by a solvent wash may be necessary. Even after that I would still test it first on a couple of the dirtiest spots. My “new” floors even had a few small spots that didn’t take too well – probably a few drops of oil from a forklift. If the epoxy won’t adhere to those you may be forced to replace the wood.
Best of luck with your project.
Steve
Thank you Steve! Im leaning towards replacing the floor. It is my understanding too that the screws are especially difficult to remove. Im thinking maybe of offering the wood for free on craigslist or something (disclosing they are treated with basileum) to anyone who will come remove them. I really would like to see what kind of condition the steel underneath is in anyway.
Thank you again!
One more thought on this, my brother suggest 1/2 dozen layers or so of 6ml plastic that I have laying around here combined with either the epoxy or a high grade rubber paint (both of which I already have around here) and then laying down new untreated ply over the top of everything…… would this block the fumes? This container is being set up for a shop and storage, but I would like to make it easy to convert for living purposes…….
Teresa:
Plastic sheets, rubber paint, and plywood are all permeable to organic vapors. The only materials I would trust to completely block organic vapors are sheet metal, glass, and certain epoxies. The only way to be completely safe would be to remove the plywood. An epoxy coating is even a compromise that could allow a small amount of vapors to pass through in certain circumstances. It is a compromise that I, although probably not others, am willing to live with, although much of my decision was based on the specific chemicals my floor was treated with. I would never trust any of your brothers suggestions though.
Hope this helps.
Steve
Thanks Steve! I guess “vapor barriers” are only for water lol It doesnt seem there is really any such thing as a “vapor” barrier. Oh well, I will just replace the wood. Thank you for all you do and your wonderful site!!
hey guys i am in the process of building container welding shop/house 2 40′s w/ doors on both ends stacked on 2 standard 40 hc’s spread 20′ apart more on that later.i am also considering the floor delima so i just like 5 minutes ago took my beloved bosch 18v impact driver put biggest phillips bit i had in it and started to easily remove the screws that hold down the floor, the hc are new and upper 40′s very clean wow that was an easy decision the floor goes! just had an idea remove floor put down pan deck/corrugated metal lay out pex tubing pour concrete radiant heating, stain to liking what yall think
Zelig:
I think a concrete floor with radiant heating would work well for a full time residence. There are examples of this on the net, but I can’t find the links right now.
Please send some pics my way when you get started.
Steve.
I hate you lol
Im fighting like heck trying to remove my flooring right now
Here’s an example of a radiant heating concrete floor in a shipping container:
http://8747house.blogspot.com.au/2009_01_01_archive.html
I thought the home turned out really well in the end.
Terry
Thank You for a great website. I have a 20 container that had a Basileum floor. I have removed the floor and am going to replace with plywood flooring. The interior has apparently been touched up with some type of spray paint. I have pressure washed inside twice with 2700 psi. I was wondering if the interior paint has or will be a problem after being exposed to the vapors from the old floor. Can you recommend a coating that would seal it, if necessary, such as Zinsser BIN shellac base primer sealer or another. The plan was to use it as an office space with paper and book storage.
Sincerely,
Barry
Barry:
I doubt there would be any problems with the paint being exposed to the Basileum vapors, especially after being pressure washed twice. The larger issue is what the paint itself might contain. It’s possible that the original paint could contain heavy metals such as lead or cadmium. As I mentioned in an earlier reply in this post, RUSTGRIP has been recommended by other builders as an encapsulating paint.
Personally, I’m not too worried about lead or other metals in my paint. As long as the paint is in good condition and not peeling, there’s very little harm it can cause. I’m old enough that I grew up with lead paint all around me – I just didn’t eat any of it. I would definitely not recommend sanding it without a respirator on, but otherwise there’s just no obvious route for exposure. All of my interior container metal will be covered with either spray foam insulation or a coat of regular paint.
Steve
Regarding the lead…… I tested my 2003 container for lead and there wasnt any……
Got the floor removed! thank you for the advice
It just “feels” better in there working now http://www.youtube.com/watch?v=jpptQFmoXfE&feature=share
Teresa:
After watching what you went through, I’m glad I didn’t try to remove my floors. That was a lot of work, but it was probably the right thing to do with an old shipping container like yours. Good luck with the rest of your project, and do send some more pics and movies of your progress.
Steve
LOL, that’s why I really didnt want to have to take the floor out! Now Im having to pop the little circles of wood off (which is a challenge in itself) and grind down the bolts, just so I can do the rust work on the C channels of the floor! LOTS of prep work to do one of these! There is a lot to be said about spending a couple extra grand and getting a newer one with flooring like yours IF they can be found! But for an older one (mine is 2003), this is real peace of mind and soul. I plan on tipping it over to check out the underside for rust as well….. eventually. The tar on the backside of the wood we removed was in tact real well though! I expect the underside to still be in good condition except where the forklifts engaged……. we shall see!
Steve,
Thanks for a great website. If I’m going to remove the floors, would you recommend a newer container? Newer containers would seem to have more toxicity (i.e floors pesticides) than an older model- older models having had more time to off -gas and evaporate, but would be a better solution as the screws holding the floors in place wouldn’t be rusty and difficult. After reading about all the toxicity, I am really beginning to second guess the idea of using these structures.
Thanks
Dave:
I would actually be more inclined to remove the floors from an older container. An older container would not only be treated with it’s original chemicals, but could also have had many other unknown, and potentially more hazardous, chemicals stored in it during it’s life here in the US. I knew exactly what my new container floors were treated with, and felt confident that I could safely encapsulate them. It’s also possible that newer containers have less toxic treatment chemicals applied to the floors – at least it seems that way with my containers.
Not all treatment chemicals “off-gas” either. When you think about it from the manufacturers perspective, you don’t want the chemicals to evaporate away and leave the wood unprotected. The theta-Cypermethrin in my floors has virtually no vapor pressure, and in theory I probably only needed a physical barrier for protection – although I feel more comfortable having an epoxy vapor barrier too.
Please keep in mind that I made these choices for a hunting cabin that will be inhabited maybe 20-30 days per year. If this was going to be my permanent residence, that I would also have to sell someday, I would probably have replaced the flooring. As I’ve mentioned elsewhere in regards to the flooring, it’s a decision each person needs to make based on their own comfort level with the chemicals.
Regards.
Steve
Hi Steve, the containers (2012 one-trippers) I am planning to buy for my project have been treated with Tailileum 400 (Imidacloprid) and based on my research seems to have a super low vapor pressure of .0000001 mm Hg at 20ºC, which according to the following link, says that this insecticide is non-volatile.
http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/imid.pdf
So I’m thinking I can skip the Epoxy step altogether, and proceed with my SM insulation and new flooring on top of it. Thoughts?
Jason
Jason:
Glad to see you did your homework – I wish more people would do the same. As to whether or not you should encapsulate your plywood floors with epoxy, that’s a decision you’ll need to make yourself.
As I mentioned in my original post, I don’t trust that the chemicals listed on the container are the only ones present in the plywood. Chinese manufacturing has a bad reputation when it comes to truth in labeling. Two of the most well known scandals were their drywall, and milk and infant formula adulterated with melamine.
The most likely hazardous ingredient, aside from any pesticides, would probably be formaldehyde. This is present in many plywood glues, even in the United States. Formaldehyde is considered a potential carcinogen and has a fairly high vapor pressure. I’m not personally worried about the small amounts of formaldehyde in plywood, but I know a lot of other people are.
If it was my container, I would probably still epoxy the floor. It doesn’t take that much time and it’s relatively inexpensive – about $100 or so per container.
Hope this helps.
Steve
The chemical listed on my plate is MEGANUIM. Any data you have on this stuff would be appreciated. I am just about to start my first mod project on a container I just bought. Your site is very helpful, thank you.
JH
Jeff:
The active ingredient in Meganium 2000 ST is Chlorfenapyr, an insecticide/miticide commonly known as Pylon Miticide. The two Material Safety Data Sheets (MSDS) I found for it listed the vapor pressure as either not applicable (N/A) or not determined (N/D). A document from the state of New York stated that the vapor pressure was less than 1×10-7 mm Hg at 25C – that’s significantly less than the vapor pressure of the Cypermethrin used in my containers. Based on that, I would say that Meganium could be a prime candidate for epoxy encapsulation.
Keep in mind that Chlorfenapyr, the treatment chemical, is not the only chemical present in the plywood. Most plywoods contain formaldehyde, and possibly other volatile chemicals, in the glues that are used. This is ultimately a decision that you’ll need to make yourself based on your comfort level with these chemicals.
Here’s a few links you may want to read:
http://en.wikipedia.org/wiki/Chlorfenapyr
http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC35810
http://greenhouse.ucdavis.edu/pest/pmsds/Pylon.pdf
http://www.fluoridealert.org/pesticides/msds/chlorfenapyr.intrepid.360sc.pdf
http://pmep.cce.cornell.edu/profiles/insect-mite/cadusafos-cyromazine/chlorfenapyr/chlorf1202.pdf
Regards.
Steve
Thanks very much for the information ,
Is Low V still your epoxy of choice? I live near a West Marine, is there anything in their catalog you can recommend?
Thanks again for your insight, very helpful.
-JH
Jeff:
I can only recommend the Low V epoxy at this time. It was the most appropriate epoxy I could find when doing my initial research. I’m sure there are others out there, but I can’t spend the time necessary to research another one. Progressive Epoxy Polymers is highly regarded in the boat building community, and was also very helpful in my non-traditional use of their epoxy.
Steve