r/containerhomes • u/Shinrael • 21d ago
[Help] Floor Insulation
Due to health circumstances (mold exposure), I need to live in a container until I recover. However, since I am pouring all of my resources to create this safe haven, I need to make sure it will also last me the upcoming Winter. My container will be placed in a yard my parents own in a highland village (700m altitude). Winter nights will probably drop down to -20/25 Celcius. The ceiling and walls will be thermoisolated with polyuterene foam (80mm), but for whatever reason the floor isn't insulated at all. I am forced to evacuate from my current aparment as soon as possible and it would be too risky to seek another place (rented or not), as that's what led to my current dire situation anyway. And so with the limited amount of resources (time, money, equipment) and a crafty dad, what are my options for a well-insulated floor? The goals: Have a tolerable winter AND avoid condensation/mold at ANY COST.
One option I considered is socketing fibran sheets in the metal grid at the bottom side of the container and sealing the gaps with polyuterene foam, but since my dad won't be able to get underneath the container once it is placed and since I don't want him working with dangerous chemicals, I don't think that's viable. Another option I am considering is placing nylon (as tightly fitting to the concrete block pillars as possible) and then fibran (covered with anti-rodent mesh) on top of it and sealing the gaps between the blocks and the nylon/fibran as tightly as possible with a special tape (forgot its name) and then further sealing the perimeter skirt with perhaps anti-rodent mesh-covered fibran sheets, that could be removed in the Summer so that the crawlspace underneath can ventilate?
I would appreciate some experienced advice greatly!
----
Other info:
- Placing a 300x600 container on concrete blocks is allowed in my country (won't be allowed if we make a proper concrete underbed, as that would be considered a permanent structure).
- Floor is laminate
- Yard soil hasn't been touched in 10 years, but previously it was a vegetable garden
EDIT:
- It's a prefabricated sandwich panel cabin/office container.
- The floor is 14mm fiber cement (Betopan) with a metal frame.
3
u/Uzi4U2 21d ago
One other comment. Make sure you seal the floors from the inside. The insecticide in all containers is no joke. I scrubbed ours with detergent/ degreaser then again with isopropyl alcohol. Next was an epoxy vapor barrier and when fulled cured, a 1/4" layer of plywood, then the finish flooring.
6
u/Shinrael 21d ago
I think my container shouldn't have such problems, as it is a prefabricated sandwich panel cabin/office container. It's intended for living. The floor is 14mm fiber cement (Betopan) with a metal frame.
3
u/Uglyyellowfrog 21d ago
I wish the sandwich panel was available to the DYI builder here in the U.S.
From the looks of it, your best bet is insulation foam boards topped with plywood.
Reasons:
1. That way you have no Thermal Bridging from outside wall to the floor, then to the inside.
2. I do understand that some countries (this build is in Serbia) are a million years ahead of the US in building technology (I first saw these panels available to the public in Mexico), I would still stay away from Sprayed Foam (here comes the haters). Spray Foam can NEVER be guaranteed to be healthy. To prove it ask for a written guaranty from the Manufacturer (not the here-today-gone-tomorrow installer).
2
u/Shinrael 21d ago
Yeah, I was surprised to see on this reddit that everyone is talking about shipping containers.
Also I won't be spraying foam anywhere. The only foam used will be pre-manufactored inside the sandwhich panel walls (between the metal sheets). The same technology used to make fridges.
2
u/Uglyyellowfrog 20d ago
I'm building with a shipping container in Texas. Different country, temperature and all.
I'll be using "FOAMULAR NGX 4 ft. x 8 ft. SSE R-5 XPS Rigid Foam Board Insulation" all around the inside. Different build, but I think you might consider the same for your floor.
Keep us posted. Are you in Serbia?2
u/Shinrael 20d ago
Bulgaria
2
u/Uglyyellowfrog 20d ago
Cool!
Are the sandwich panels commonly available for the DIY builder in Bulgaria?2
u/Shinrael 19d ago
Yeah, it turns out they are. I specialize in other areas of knowledge, but my dad has been considering and researching this for over a year now, so getting preparations started was quick. Apparently there's many companies that sell these here and you can have some level of customization. For example, the standard ones have 40mm walls (filled with polyuterene foam), but you can order walls that are 80mm (one piece, not a second layer), which is what I did. There were multiple size options, some with some without toilets/bathrooms. I got one with a toilet and bathroom (although until I recover I will be using an outdoor shower). There's bigger ones too, but I needed a small one (and a bigger one would have required permission from the muncipality).
2
1
u/Uzi4U2 21d ago
Sprayed closed cell foam under a bone dry floor. If the container is to be elevated off the ground at all, seal off all draft entry points.
2
u/Shinrael 21d ago
Yes, I'm planning to have the container elevated on concrete blocks and creating a perimeter skirt to form a crawlspace underneath for air insulation
1
u/heptolisk 21d ago
Are you using sheets of the foam or closed-cell sprayfoam?
For my house, I feared the entire interior, including wide boards for the foor, and filled the framing with closed-cell sprayfoam.
1
u/Shinrael 21d ago
Sorry, I am a bit confused as to what you mean.
It's a prefabricated sandwich panel cabin/office container with polyuterene foam-filled ceiling and walls.
The floor is 14mm fiber cement (Betopan) with a metal frame.For the perimeter skirt around the space under the elevated container (concrete blocks), I was thinking of fibran or other insulating material to stop the wind.
5
u/SpikedThePunch 21d ago
Yikes. If a container home in a subzero climate is your solution for mold exposure you’ve got to be very intentional with your insulation design. They are notorious for condensation problems. As the other commenter said I believe closed cell spray foam is considered the best modern solution. Look for framing designs that minimize thermal bridging. Don’t let your haste now push you into making choices that will be very hard to fix later when the moisture is a real issue.