Email question: “We are in the process of relocating to NE Florida, and would like to build a home with alternative building materials. It would seem that straw bale homes are not the best solution for Zone 9 [ed: due to risk of moisture damage]. What is your recommendation for the best building material, based on climate/humidity in the NE Florida coast? Is earthbag the best?”
Owen: Yes, I think earthbags are the best option in your situation. You’ll probably have to stabilize the fill material with some lime or cement to meet code and to better protect against moisture damage and insects. Code will also likely require some sort of extra reinforcement. This could include wood posts and beams or reinforced concrete posts and beams. In addition, there’s also the system used by Structure1.com who’s the only engineering company right now doing earthbag building.
Note: these three methods all allow you to build virtually any size or shape home. Building in the round is best in high wind areas because it will blow around the structure and not build up pressure. Be sure to use strong roof tie downs so the roof doesn’t blow away. In addition, code areas will also likely require a concrete foundation.
Also, research passive cooling strategies on our blog. Making smart choices in this area will save you a lot of money and improve the comfort of the home.
Passive Cooling Strategies for Hot Climates
Additional Passive Cooling Strategies for Hot Climates
I am serious about sandbag/earthbag for Florida – specifically the Gulf Coast. Round and domed, hurricane proof. Flying objects in high wind won’t spear the inhabitants! My question is about mold growing INSIDE the bags,leaking out and causing health problems and complications in the integrity of the structure or surface. What are your thoughts? Obviously, the Indigenous People lived in elevated open air structures, ready to rebuild if destroyed in a storm. Mold not so much an issue worth open air and frequently replaced natural materials. Our desire for permanency also leads to mold and other problems. What about tiny homes on wheels that can roll out to safe havens? The rectangular and top heavy design doesn’t seem good for frequent high winds in hurricane season
Mold is not an issue if you build correctly. Do not use materials that promote the growth of mold such as wall paper, carpet, wafer board, sheet rock and so on. Include good air circulation including ceiling fans and roof vents. Carefully plaster the exterior to prevent leaks. Those are a few of the main points. So yes, earthbag can be extremely practical in Florida. That’s why there are numerous articles on this blog about using earthbags for Disaster Resistant housing such as this one:
https://naturalbuildingblog.siterubix.com/open-source-disaster-resistant-earthbag-homes/
It is prudent in my opinion to have a Plan B (back up plan). A tiny home on wheels can serve multiple purposes. It can be used to live in while you build your home. You could use it for travel and for guests. And, it could be used as a way to escape severe emergencies. Get away well before the storm and high winds would not be an issue.
Maybe use some hempcrete with a hint of volcanic ash as your pad and stabilizer mixture for the bags and as a stucko for the exterior.
Then what I would personally do besides doing the tying down and structural reinforcement with beams internally to meet code.
Is to get a hold of some large thickly woven hemp hescos or normal ones and then add the hemp crete with volcanic ash then stack them 2-4 blocks high and run an outer wall with some steel or wood beams added in for more protection
Thats a way to absorb everything coming at the structure as well as keep the roof and walls in tact during storms.
You can even anchor those in the ground deep too for the inner outer and roof structure that way.
The rot would probably be minimal and its all non toxic mostly cept maybe for the ash which how bad could it be really and more importantly where would you get enough cheaply.
Maybe sand is just as great and cedar dust. Ok I’m spitballing.
I like the idea of a dry area with clear plexi or glass added in so I can tan my hide.
Honestly I would think in florida you would want it on pillers and round . you want it on pillers so the storm surg isn’t a problemwhen the next huriane comes through and round so the huricans are less likely to rip it apart.
Yes, raising the foundation is good near the beach. I’m describing how to build in the whole state of Florida (and similar places because people often ask).