Matilda Hernandez-Miyares

Made this video for an organization I am a member of, Forest Reciprocity Group (FRoG). We have an emphasis on popularizing the use of small diameter fir poles for building. Last year started hopping around from member to members homesteads and getting out and working in the woods together. Our month was October and we built a round pole woodshed with the help of 15 friends and 7 electric chainsaws. This was our first attempt at video editing, so feedback is appreciated!




For the October Hop we wanted to prove the efficacy of simple building with locally abundant Douglas Fir poles. We chose to forgo the laborious bark stripping process, with the idea that late summer harvested poles were already very dry and therefore would not be prone to shrinkage. What gave us confidence was discovering an old goat shed that had used unstripped poles and was still in good condition 40 years later. The project was designed as a family fire wood-shed, that would provide dry storage in the winter, and fire conscious location in the summer months. It was sized to hold enough wood to heat our houses for up to three years.

Having a group of people to help us informed the design, allowing us to work with 30ft tree sections, as well as exponentially speeding up the time construction took, and fun. Each person brought their skills, tools, and a willingness to share and learn.

In the process of forest thinning, land owners had already picked out some trees that were nice and straight, saving them for building projects. In the days proceeding the Hop we poured the foundation footers, and harvested the trees. The rest of the work of cutting to lengths, adding mortise and tenons, was done during the weekend.

In ode to the ongoing fire thinning and biochar production projects on site, I decided to incorporate up to 60% charcoal during the creation of the foundation blocks. In this way reducing our need to import dwindling sand resources, while creating a lighter weight, fire resistant concrete solution. More experiments using biochar in concrete and cob building are promising directions for land stewards to investigate.

Another technique was employed by driving concrete stakes (3/4”) up into the posts. A jig was created on the fly to send a long speed bit per These posts would then easily slip into steel pipes set into the foundation blocks, thus holding them upright as we assembled the rest of the structure. Tar paper and squares of hog fencing were added between the posts and the blocks. In the end the whole structure was resting on the steel pipe a good 1/2 inch off the foundation. We were happy with this to prevent standing water and end rot.

we are doing it.. its awesome! like with cement you need to hydrate the char before use. It can hold six times its own weight in water, so you must factor this into your mix. You can work with this "internal curing potential" in both cement and cob. Meaning it will dry faster, and from inside as the char soaks up moisture, so be prepared.

I only partially hydrate my char before dry mixing in the sand and the straw in a wheelbarrow. Then I add the clay and mix by hand... adding water as needed. Leaving this overnight can yield a nice dry moldable char-cob. I arrived at this thru trial and error, you will have to adopt to your particular ingredients.

Ive been using Manzanita char that I sent thru a wood chipper, that left me with 1/4 inch chunks down to powder.

6 shovel-fulls char  /  2 shovels sand  / 2 hand-fulls rice straw  /  2 pails (~2 gallons) blended clay soil (wet)  /  1 gallon water.

I love to potential to replacing much of the sand in earth building, with biochar. It could mean lighter better insulated buildings made from a carbon negative material that can be made locally from a wide variety of sources.

Wanted to share an update, we made a frame with some scavenged pig fencing, wove in a some bamboo to fill in the larger holes. Frame structure rests against the inside wall on all 4 sides and we reinforced it with some big old brad staples + cobbing over the internal frame overlaps.

For the bottom we poured a slab of char-crete [~6 parts biochar ((presoaked!)) to 2 parts Sand and 2 parts Portland Cement- with a piece of pig fencing in the middle.] We poured the slab on a piece of plastic, which seemed to slow the drying process but it made a very smooth surface. (we waited about 4 days before messing with it)


Now we are making our way up the sides with Char-Cob, decided to have one inset cob shelf (by resting split bamboo on the metal frame and cobbing over)

Kimi Iszikala wrote:
For what it's worth, we are making our cool pantry with solid walls, but have a 4" screened vent coming in from the bottom and another 4" screened vent going out the top.

The reason it might not be worth much is that we haven't finished yet, so I can't report on how that worked!

Good luck with it!  Let us know how it goes!

Thanks for sharing your project! Are you going to have doors on the vents or have them always open?

In terms of the straw infill: main mark against it in my book is the thermal bridging that occurs from the wooden studs loosing one of the thermal benefits you get with a more continuous earth method like cob, earth bag or strawbale [which I didn't understand until well into the project] and its still a lot of labor! Not to mention using dimensional lumber- bound by corners.

On the plus side, allowed us to do thinner walls (which may or may not end up being a benefit) and with the plaster and everything it feel very nice and cozy in there.

This project is a 2 story add-on to a little cabin standard stud framed we are building, was a sort of our transition into earthen buildings.

@Matthew- Funny, I haven't built with straw bale but figured it was easier and more efficient then the straw infill.

Been working on this pantry addition to our little cabin. Project was straw-slip packed between dimensional studs, was a good learning process, though I don't think I would use the technique again. Anyways here we are, trying to finish the project, room has gone through a couple different designs before we decided it was gonna be a pantry/storage space. In the midst of those changes we find ourselves left with this hole in the NORTH side wall.



Decided to make a cooler box, probably for storing, ferments, cultures, maybe veggies?.. Inspired by something we saw at the cob cottage company but its been a few years and the memory is vague. From what I remember basically a cob box set through the wall, that they were storing raw milk and veggies, left over food, etc in.. I think it was their only "refrigeration" of sorts. Not as cold as a fridge but enough to give things a little buffer from spoiling.

Note:  We are in Northern California- Mediterranean climate, with cool wet (hopefully) winters and drrrrrrry summers. At about 3000ft so we don't get usually get over 93°F and even in the summer night time temps are cool.

Thoughts on: Should we do a full box? or partly open with metal mesh for breathing?

playing with the idea of incorporating some evaporative cooler design but feeling a bit daunted with how to combine with uncooked clay.. Have seen a version using just wool, could work behind the metal mesh (to keep the critters at bay) but given our climate, feels like we may be letting in more heat with the permeable sides plus balancing the water so we aren't damaging the cob... (The box will probably get a little sun hitting it early in the morning, otherwise only be indirect light.) Granted we may really need some air exchange... Also we have a lot of biochar, know that has good humidity buffering properties.

Wondering if anyone has some thoughts? Or tried something similar whose experience we could learn from?

Hello Permies,

A lost Gert here, recently found myself living at a place with softened well water... Previous owner decided to deal with situation by running everything through a water softener (including the two outside hose bibs). Looks like some blue chemy gic, I am told is "just sodium chloride"

Current land owner believes it is essential for lifespan of water heater, etc. I am very dubious! Even with the gic, the water leaves white residue everywhere. And what happens to all the salt? Currently running into a septic system, seems like the salt build up would be a big problem. Also if I am to stay long term would want to do greywater watering, is that even an option with softened water?  

Had some issues with a worm bin we set up (before we figured out the outside hose bibs were also softened) and am now scared to water anything, carrying water from a nearby structure that isn't softened, ok for a couple indoor plants but once the rain stops will be fairly limiting. [I mean could be a good design challenge...] Except salted water still runs into my local environment every time I run the tap! I got a berkey filter for drinking water and am trying to convince landowner to pull the softener out, or find an alternative. So far not getting much traction.

Wondering if anyone has some advice on dealing with the situation? Am I overreacting to the salt content? Also why does the water turn blue when I boil potatoes?! Or when leaching acorns?