Post and beam systems have a number of advantages than can improve your earthbag project.

Post and beam systems have a number of advantages than can improve your earthbag project.


One of the biggest advantages of building a post and beam frame is you can get the roof on quickly so you can work in the shade and out of the rain and snow. That’s a huge plus. Other advantages include ease of getting code approval and added stability. Use a firewood permit to obtain poles from a local forest and the cost is negligible. Again, check your code situation because many areas don’t allow wood that hasn’t been inspected. (One more reason to move to a sparsely populated rural area with few building codes.)

Another big advantage, and the main reason for doing this blog post, is you can more easily incorporate lightweight insulating earthbags. This would work great in cold areas such as the northern US and Canada. One suggestion is to use scoria or pumice filled bags on lower courses until you’re safely above risk of moisture problems (possibly to window sill height so you have a sturdy base to set window bucks), and then switch to a higher R-value fill material such as perlite or vermiculite. Imagine 15” of perlite at about R-3 per inch. That would get you close to R-45 walls. That’s overkill in most climates, but it would sure be great if you lived where it’s extremely cold. I don’t know of any other wall system that gives you this high of an R-value without spending a load of money on double walls and/or expensive materials.

There are numerous beam options: TJI beam (shown above), laminated beam, beam made of double 2x lumber glued and nailed together, log beam that sits on top of the posts.

Post options include: different types of pier footings and placement either on the interior, exterior or embedded within the wall (shown above). Embedding the posts protects the wood and doesn’t take up floor space. Plus, this method puts the beam right where you want it on the perimeter of the wall.

Oh, and by the way, you can easily pin the corners of earthbags so they fit nicely around the posts. Simply pull one corner of the bag as you’re closing the top and stitch it somewhere near the middle of the bag. Here’s a video of the general idea. Do something similar, but offset one corner more than the other. http://www.youtube.com/user/naturalhouses#p/u/59/Vbs_-jImzPY


Comments

Post and Beam Earthbag Houses — 17 Comments

  1. Wondering what the best method of anchoring a post and beam frame to the courses of gravel bags. Or, am I missing a transitional piece. I have the rubble trench going and 2 courses of gravel bags. I’ve seen recommendations of cinching it down with wire or tape and I’m only slightly convinced – is this enough(?). I’m planning on earth bag infill.

    Any one want to collaborate or chat about building, I’d love to hear about your project!

    • Posts should ideally be set on solid masonry material. These posts can either be within the earthbag wall or set inside or outside that envelope. I would suggest a concrete pier placed on the rubble trench so that the wooden beam is clearly above the top of the trench. The beam should be firmly pinned to the pier.

  2. Do I need a foundation for an earthbag home with a post and beam structure? Could I just use build using my initial bags as if the entire structure was an earthbag home?

    • Earthbags are very heavy. That’s why there’s typically a rubble trench under the walls. The depth of the rubble trench depends on the bearing capacity (strength) of your soil. Also, be sure to use gravel bags on lower courses so they don’t get damaged by water or snow.

  3. Would a post and beam structure with earth bag infill need buttressing? Or do the post provide enough stabilization? And would the bags need to be attached to the posts?

    • No buttresses will be needed when done correctly. Yes, attach the bags to the posts. This can be done inconspicuously with anchors. This is in my book and DVD, and also in a blog post here about sheet metal anchors.

  4. I am curious how earthbag as infill would work if you already have the roof up? I have seen one earthbag post and beam that used infill but they didn’t have the roof on it. How do you tamp the top rows with the roof there? I would want to build something that has potential to get code approval, although where I want to build wouldn’t need it.

    • There are various options for doing this. You could tap the top few courses with a 2×4. You could fill the last few courses with lightweight fill material such as scoria. You could remove the lower courses of roofing and replace them after the earthbags are in. The easiest is to fill the last few courses with scoria.

  5. After looking through more of this guy’s channel, I have come to the conclusion that he is a subcontractor. Probably a sandblaster that works extensively with primary contractors that restore old houses. It appears this particular guy specializes in cleaning off modern paints and plaster products off old structures. He is constantly pointing out the damage caused by trapping moisture inside of walls.

    Looks like he has helped clean modern crap out a lot of very old buildings.

    • That reminds me of the old adobe Spanish churches in the southwest US. They lasted for centuries until they got covered in cement plaster and then they quickly started eroding from the inside due to trapped moisture. Same with strawbale, wood houses, etc. Moisture trapped in walls is a big problem — multi-billion $ in damages. Always allow for moisture to pass through walls.

  6. I don’t have the slightest clue where to drop this link, but I suspect Owen will find this one interesting.

    It’s a timberframe house from the 1600’s. That’s right. It’s about 400 years old. It’s in desperate need of extensive repair and restoration, but one advantage of the current state of disrepair is that its bones are exposed and on display for us to see, appreciate, and learn from.

    http://www.youtube.com/watch?v=_vAxgYLK4dQ

    Note the wattle and daub infill in some areas. I suspect that is how the initial walls were built, and perhaps that old wattle and daub is the actual original and is now 400 years old. The brickwork infill probably was added later. Then repaired several times.

    I haven’t watched all the videos from this channel, but it appears that there are a lot more videos showing a lot of details about the 400 year old techniques used to build this old treasure. Also… he shows how some attempted repairs using more modern materials have actually caused much of the damage to the old structure.

    Fascinating stuff… for those that are into rediscovering the old ways.

    It’s worth a look-see.
    Enjoy.

    • That one’s only 400 years old. I just pulled together a blog post earlier today on 1,000 year old timber-frame houses in Germany. I usually wait at least a few days before publishing blog posts so there’s time to tweak the text.

      I’d say that guy has his work cut out for him. But he should end up with an amazing piece of history when he is done.

  7. Johnny, would love to see a picture that describes this.

    I’ve been trying to work it out and am concerned that the inner tube would sag at the pole, and this would affect the channel.

    Or are you saying that it just wraps around the pole fine?

    I just ask this as I can see us having a very hard time meeting code in Australia, but a post and beam earthbag house seems achievable. BTW, you deliver overseas?

  8. Hi Owen
    Eternally Solar Earthbags, work well with gumpoles, in that the outer filled tubes wrap around the outside of a 100m pole, and the end of the central web deforms around the pole (the half diameter). This also means that the rigid pole is kept separate from the more flexible wall skins, hence reducing chances of cracks developing. Any horizontal stiffeners (lintel or ring beam) built into the channel, either reinforced concrete or timber, can then easily be tied into the vertical pole system.

    Much stronger than ecobeam in terms of wood frame and sandbag systems.

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