Tiny house build in Hokkaido

It certainly is interesting. Who would have thought of it as a proposition.

So this is where we’re at. Doesn’t look like much in the way of progress, but the foundation is the only part I know we can’t fix once it’s done so we’re taking extra precaution to get it right the first time.

The only gravel we could get at a reasonable price was mixed unwashed seconds. Ended up getting 4 m³ of the stuff. Then shifting and washing all of the gravel. Leftovers used as road days so not a waste but extremely time consuming nonetheless.

Also got some sample rice hole to start experimenting with an insulation for the walls. Will start with lime that we have and see what kind of consistency we can get.

Will keep you posted on our experiment.

Here’s a few images of what we’ve been doing.

Going to pick up some more free lumber from a local demolition site.

Cheers Peter and Co.⛰🍄⛰

Seeing your progress washing and sifting your rubble trench reminds me of my experience in the trenches. Most of my small rocks however came from a river so it was already pre-washed and if you looked around, certain areas were naturally separated already. I think I recall you and Mimi scavenging for rocks in winter for your dragon in a river and noticing this too.
It does take a lot though, so I can see you being at it for a little while. Through all the washing and sifting though, I bet it does make you much more aware and appreciative of where things come from and how much processing is involved with even simple base materials like this.

Keep up the great work! Always look forward to your updates.

Thanks buddy!

Definitely faster than when we first started and the backhoe is a life saver.

Got some wood for free!!!

Peter

Nice score on the wood. All those memories and things that wood must have 'heard' all these years and are now being transferred to another structure where it will live again. Any scraps remaining I'm sure will  be burned in a rmh to keep warm this winter!

PS. I love the monster like shadow of your hand on the truck door :)

Didn’t even notice the shadow. Good call. Never driven a big rig like this before, but I spent all winter in a tiny Japanese pick up and that probably made it easy for me to get used to driving this thing.

Yeah all the memories good and bad, laughter and tears, transformed to a new beginning, a new life. I’m totally stoked on  the concept of collaging together pieces of history for a new future. On some artistic kick...

Cheers, Peter✌️

Shin through my window and my friends they come around...⚡️💀⚡️

Getting somewhere. Measure twice cut once, measure twice cut once...🤓

It’s a battle for sure, but getting lots of guidance from Yoshida Sensei...⛰🙏🏼⛰

Battle continues. Weather is not very cooperative, so were doing our best to plug along in the drizzly rain. Hope to have the foundation under wraps within the next few days. Here’s a look at our progress today.

Been researching as much as I can on rice husks and found a local farmer who is willing to give us as many as we want for free just have to find a way to transport them. I think we’re really going to try to make a house out of rice, which is probably fitting seeing that we are in Japan. Use what you have around you...

Peter and Co⛰✌️😁✌️⛰

Why is the step being created on the perimeter beam?

John C Daley wrote:Why is the step being created on the perimeter beam?

Hey John,

Making a single pour foundation beam with a 20cm tall short section of concrete steam wall to bring us up to grade. The short section is 40cm wide, same width as the intended two course block wall. There are three courses of 10mm rebar imbedded in the base footer, an additional two courses set in the middle of the top 20cm section, and vertical 10mm rebar set throughout to coincide with both the inside and outside courses of block to tie the whole thing together.

The purpose of the T-shaped footer is to reduce the amount of concrete required for the pour, and to get us back to grade so none of the blocks come in contact with the soil. Once the foundation is set I will infill, hand tamp, and re-grade so that all potential water flows away from the house.

This is what was suggested as a strong and viable option, by our local contracting neighbor Mr. Yoshida, based on his understanding and expertise of construction and local soil makeup.

Is there some aspect of this configuration that raises concern in your eyes?

There’s no zoning laws or code requirements in the area that we live so it’s pretty much a free-for-all, but of course I want to ensure that we maintain a safe level of structural engineering throughout the whole building process.

Our neighbor says that we are over engineering the building for the size that it is. Living space: 3.7m x 4.8m or 10.3’ x 16’

Feel free to share your thoughts.

Cheers, Peter✌️🤓✌️

Just picked up two large format triple glazed windows, this morning, for $75. Start to think about layout and construction...🤔

Trying to work out windows and stuff...🙄

So we have a bit of down time as the rain refuse to let up. Doing as much calculations and planning as we can while we wait for clearer skies.

I decided to try and mix a bit of the rice hulls and lime putty I had on hand just to get a feel for what the material might be like. Just eyeballed it’s and tried for a rice crispy treat kind of consistency. Also added a small bit of sifted hardwood fire ash to the mix. Was thinking of using rice husk ash as an additive in the future mix as it seems to have pozzolanic properties that should be beneficial.

Really not sure if this is right, as I’m not sure what I’m going for. Just put it in one of the small molds that I had made earlier for LSC block experimentation. Didn’t really tamp or press, just filled the mold. Letting it sit now. Not expecting a solid block, but the only video tutorials I could find were on recipes for Hempcrete so I just kind of followed that. Here are a few images of what it looks like.

Was wondering, once we fill the wall cavity with rice hull biocrete, how long do we have to wait for curing, so that we can at least plater the outside of the wall for winter?

Any advice would be much appreciated.
We’ll keep posting as we go.

Thanks in advance, Peter and Co...⛰🍄⛰

Thanks for sharing. Very exciting. Best luck.l

Only thought is to be paranoid and anal-retentive about water. Where it flows, how it seeps, etc, etc. Water _will_ get anywhere it can - it's ruthless and unrelenting. Also relates to snow levels and melting.


Cheers,
Rufus

Rufus Laggren wrote:Thanks for sharing. Very exciting. Best luck.l

Only thought is to be paranoid and anal-retentive about water. Where it flows, how it seeps, etc, etc. Water _will_ get anywhere it can - it's ruthless and unrelenting. Also relates to snow levels and melting.


Cheers,
Rufus

Totally hear you on this. That’s why we are making a 60cm stem wall and large overhangs on the roof. Not sure that will be enough, but hoping. If need be I’ll put some sort of rain screen skirt along the bottom of the house moving forward.

Relentless...😬😵😬

John C Daley wrote:

The ricecrete mixture is far too light and crumbly to accept plaster directly. Rather than install ricecrete in moveable shuttering as I would for straw-clay, I hold it in place with permanent lath, installed prior to the infill. For lath I have used split bamboo, thin wooden slats, and also reed mat which is readily availble in hardware stores here. I don’t know whether mesh would be stiff enough on its own to do the job - it probably depends on the distance between your framing members. With the lath in place, there is no need to compress the ricecrete as it goes into the wall. This is advantageous because less compaction means more air in the wall, which means better insulation - and also less materials cost, less weight, less mixing, etc. I would not add any kind of fiber to the ricecrete because it would make it harder to mix, harder to install, and less likely to fill narrow cavities completely. Do be careful as you are filling to move the ricecrete by hand underneath electrical boxes or any other horizontal obstacle inside the wall cavity. You can lath one side of your wall completely and then on the side you plan to fill from. Don’t do more than 50cm vertically at a time so that you can reach the bottom and make sure that the cavity is completely filled.

Hey John,

Working out the logistics of the ricecrete once we get the timber frame up. The mix I made as a test is hardly looking like it is going to hold together. Here’s an image of what we have right now. Think if I picked it up it would just fall to pieces. Will work on getting the recipe right. There is a local lime processing plant down the road. Gonna have a chat with them about getting some fresh lime. The homemade slaked lime we have in buckets is far from enough for what we need and probably better used elsewhere in the project.

You described the reed lathing that you’ve  made in the past and this is what I’m imagining it to look like. (See image below) It’s summer here so they sell these reed mats at the home center for pretty cheap. Think this is what we need. I’m I correct?

Still working on finalizing the foundation, but trying to stay two steps ahead in the process.

Any guidance and advice here would be much appreciated.

Thanks in advance, Peter & Co. ⛰😎⛰

Peter, the lathe you have shown is the principle I spoke of.
As for drying time, how long is a piece of string?
Because its raining where you are building it will take extra time.
I bought a book detailed, believe it or not , called " Japanese earth Plastering" !!
It may have details of drying times required.
I have seen places, cool rooms, where the fill material is just poured in loose.
Have you considered that?

I think your thinking on the foundations are good.

John C Daley wrote:Peter, the lathe you have shown is the principle I spoke of.
As for drying time, how long is a piece of string?
Because its raining where you are building it will take extra time.
I bought a book detailed, believe it or not , called " Japanese earth Plastering" !!
It may have details of drying times required.
I have seen places, cool rooms, where the fill material is just poured in loose.
Have you considered that?

I think your thinking on the foundations are good.

When you say just poured in loose you mean without any lime binder?

If I were to use the lime rice husk mix you we’re suggesting we would be waiting for the whole of the infill to dry before applying plaster to the outside if the lath reed mats? It has been a bit rainy lately, but we should get a few months of decent weather before it gets cold. Probably safe to say we have a window till later October.

Can we use clay based earthen plaster on both sides of the wall to finish? Linseed oil to protect against elements. Would it be better to include some lime in the clay plaster mix?

Foundation is almost ready to go. Digging footers for the two posts that will be set in front of the house to give us some overhang space and protect the entrance area. Mr Yoshida made us some post support brackets yesterday. Will set into the footers and notch out posts to fit. They will be set above grade to avoid potential water damage.

Here are a few images of what we are doing including a few that represent the look and feel of what we are hoping to achieve in the end.

As always thanks for the input and guidance.

Peter & Co⛰😎⛰

On another note.

We are planning to do a earthen floor in our tiny house. After calculating the volume of perlite we would need to get a decent amount of insulation we feel that the cost is a bit higher than we have budgeted for. (House was a last minute spur of the moment decision.)

I have begun to experiment with making a cob mix heavily filled with rice hulls. I have cast a test block of the material. No measuring of ingredients as of yet. Just threw rice hulls, sifted clay rich soil and sifted fire ash in a bucket. Then added water until the mix was just able to hold together when I squeezed it into a ball. Threw that in a test mold and spread it eventually, not pressing extremely hard. Took it out of the mold after 5 minutes. Holds its shape just fine and looks as if it will set up as well.

If the test is successful, the idea would be to apply this mix in layers of about 3-4cm. Maybe a total thickness of 12cm or more all together. With the amount of clay required I’m sure the insulation value will decrease but I’m thinking if it’s thick enough it will be a decent base to put future layers of earthen plaster on to finish.

We plan to level the area and add a layer of gravel first. Then two layers of salvaged carpet, one of which has a rubber backing on it. Some sheets of salvaged polyethylene insulation. Then more tamped road base. The rice hull mix would be next, then a finish plaster with linseed oil.

Was thinking of using this under our mass in our RMH build as well with a potential layer of closely arranged large glass beer bottles for a thermal break.

I don’t believe there would be high enough temperatures in the floor area of a bell bench system for there to be any issue and if some of the rice hulls burn out and turn to charcoal or ash the remaining material should be so high in silica content that it would act as a basic form of refactory material.

Thinking of adding additional pre-made rich hull ash to the mix at the beginning as well in place of the usual fire ash Donkey and Matt have used in older home made refractory mix builds.

To me this seems like something worth trying.

Any thoughts?

I have read a number of articles where they tested rice hull ash as a refractory insulation material and have hade great results.

Will be using low density IFB for the core and base of our heater. The mix would only be used under the mass and as additional insulation along the wall that our bell bench butts up again. Very similar in execution to our previous build.

Let me know if anyone thinks this has potential or is just straight crap. I’m hopeful , as I can get lots of rice hulls to work with at only the cost of transport.

Cheers, Peter✌️🤓✌️

What is IFB please?
Clay based earthen plaster both sides will be good.
A lime wash will be better than the oil you mention.
The best way to protect any earthen based wall is eaves.
Otherwise regular maintenance is required, even in deserts.

Hey John,

IFB- insulated fire bricks. Topic begins to fall into more than one category.

Thanks for the tip on the lime wash.

Planning to have the eves hang over at around 80cm.

Could you clarify the benefit of using the lime rice hull mix vs just dry rice hull infill for the wall cavity? Less lime means less cost. Should we use borax on dry rice hulls, if we chose that method of in fill? Is there any significant difference, structurally, between the two in fill methods?

I’ve done a fair amount of digging on the web, but there doesn’t seem to be a vast amount of information available on technique and build application with regards to rice hulls. Most seems to fall under the broader topic of “biocrete” construction. Closet thing seems to be hempcrete, but even that uses removable form work, so still considerably different in actual application.

Thanks again for the quick response.

Cheers, Peter

Peter,   The picture of the rice hull brick looks great but may still have a little much clay if your going to rely on it for insulation. That's great that you have access to so much of those rice hulls. As usual, your innovation for finding and using what you have available is inspiring.

Gerry Parent wrote:Peter,   The picture of the rice hull brick looks great but may still have a little much clay if your going to rely on it for insulation. That's great that you have access to so much of those rice hulls. As usual, your innovation for finding and using what you have available is inspiring.

Thanks Gerry!

I see people using bottles in the flooring under their mass a number of times. Claiming that it’s a “thermal brake” Is this a useful addition to the insulation under the mass? Not sure I fully understand their proposed function and read mixed reviews about bottles in general. Any light you can shed on this would be much appreciated. “Thermal break” and insulation are two different things? Convection currents inside the bottles are a potential issue? If using bottles are they capped or uncapped?

Cheers, Pete 😎

Here’s a quick drawing to illustrate the sandwich construction in layers I am considering.

Peter 🤓

Hey Gerry!

Just cast a new version of the rice hull and clay mix, with much less clay than the first batch. I’ll give it a day or two before I u-mold it and see how it looks.

My biggest two concerns for using rice hulls as a subfloor insulation system would be:

1. To much movement from pressure above, i.e. walking around on it, making the top finish plaster sag and crack.

2. Building it up to a thickness to get decent insulation value and having the rice hulls mold and deteriorate in the subfloor.

I know rice hulls are supposed to be less prone to mold than other cellulose base materials, but I’m still not sure how far I can push it.

I have to keep reminding myself that the space is relatively small so shouldn’t require as much insulation and effort to maintain comfortable living temperature. The R-values required for a 3 store m mansion are quite different from a tiny box house.

It will get its own tread in the not too distant future, but for now here is a quick look at our dry stacked rocket core, based on Matt Walker’s riserless layout.

Rain rain go away...

🌨🙄🌨
 Peter

I followed up your request for more data.
I searched for; Use of Rice hulls as insulation

rice as insulation and why it works

The hull is a very tough and abrasive packaging material, consisting of two interlocking
halves. It encapsulates the tiny space vacated by the milled grain, and in proximity to a
myriad of other hulls, it forms a thermal barrier that compares well with that of excellent
insulating materials.11 Thermal resistance tests on whole rice hulls indicate R-values
greater than 3.0 per inch.12 If the R-value of rice hulls is so favourable, why have they not
been used extensively to insulate residential and commercial structures?13
Perhaps our scientists and engineers focus only on creating materials and products that
can be labeled and marketed as proprietary.
Perhaps the humble use of the rice hull as an insulation material does not sufficiently
inspire the scientific or commercial imagination. But why focus on man-made
products when natural materials abound?
Surely there must be some profound and obvious reason that makes the raw rice hull

Rice husks are flame retarding and, at ordinary temperatures, self extinguishing.
A lighted match, tossed onto a pile of rice husks will generally burn out without producing a self-sustaining flame in the
husks.


Rice hull / cement combo for insulation
Summary of the mixing process: soak the whole rice hulls in equal volume of water for 30 minutes, mix cement separately, drain the rice hulls and slowly add them to the
cement mixture and then mix until uniform in consistency. A cement mixer speeds the process.
Ratio of rice hulls to cement mixture is between 3:1 to 4:1, so only minimal cement is needed.
And the cement mixture may be 5 or 6:1 sand / portland cement

Thanks for the info John!

I had previously read a few of those articles you sent. That’s what got me thinking the rice hulls might work in the floor. However the one regarding the concrete mix was new to me.

I was originally thinking of using perlite as an insulation material between the two courses of cinder blocks, which make up our stem wall. I thought this was necessary, as the blocks will be at or just above grade. Based on the information you sent, it seems like I could just infill the 10cm gap, between the two courses of block, with the rice hull and concrete described in the article. There isn’t any issue with decomposition of the rice hulls in this environment, which could cause issues in the future?

This would be a much more affordable solution to stem wall insulation.

Appreciate all the advice so far.

Cheers, Peter ✌️

Peter Sedgwick wrote:I see people using bottles in the flooring under their mass a number of times. Claiming that it’s a “thermal brake” Is this a useful addition to the insulation under the mass? Not sure I fully understand their proposed function and read mixed reviews about bottles in general. Any light you can shed on this would be much appreciated. “Thermal break” and insulation are two different things? Convection currents inside the bottles are a potential issue? If using bottles are they capped or uncapped?

Cheers, Pete 😎

I have absolutely no experience using glass bottles other than drinking the contents from them. I'll take a stab at what I think the difference is though. Thermal break to me is a layer of some sort that stops the transmission or travel of (in this case hot or cold air) from going any further via conduction, whereas insulation could be seen as having many microscopic thermal breaks throughout the entire thickness of the material slowing temperature variance travel via radiation. Nothing you probably didn't already know but there it is anyway.
But another subject you'll be exploring further for me to vicariously learn from you I'm sure!

Peter Sedgwick wrote:My biggest two concerns for using rice hulls as a subfloor insulation system would be:

1. To much movement from pressure above, i.e. walking around on it, making the top finish plaster sag and crack.

2. Building it up to a thickness to get decent insulation value and having the rice hulls mold and deteriorate in the subfloor.  Peter

1) I would say that the rice hulls are going to be similar to stabilised perlite. As long as you tamp them tight enough to remove air gaps, movement should be to a very minimum. Unless your going to be driving a forklift in your house or hosting wild clog dancing parties, you should be OK.
2) From my understanding, mold requires air to grow. I would say as long as it thoroughly dries out before you put your final seal on, your basically mumifying them within the clay. I see this as a perfect place to make a time capsule for the next builder to find messages and objects that would be fun to find.

Rain rain go away... Raining lots here too! One good thing though is that the lettuce growing here is loving it!

BORAX NEEDED??

Page 52 details rice building report
In Uganda, the cool room was constructed in an innovative fashion with two concentric mudbrick
walls separated by a 30 cm cavity that was filled with plastic bags filled with rice hulls. The
problem addressed in this situation is that organic insulation materials will quickly be colonised
by termites unless protected, hence the plastic bags. We had also tested the possibility of using
dried grass treated with a solution of borax to reduce the palatability to insects.

I am checking on the corret ratios of cement in the rice concrete

Using rice on the floor- This may work

Sticky rice mortar

Sustainable building with rice hulks
Building with rice hulks

From this I see that when rice concrete is made it has portland cement and sand to create the end product. I am still investigating the ratios of sand cement and rice.
I suspecty it may be similar to mortar IE 5 or 6 :1 sand / cement.
Although from experience I would experiment with leaner mixtures, say, 8: 1 or even higher.
Lime may work as well in lesser quantities.


PETER, WHY NOT PRINT ALL THE SHEETS OF INFO YOU COLLECT INTO A FILE. IT WOULD BE A GOOD RESOURCE AND MAY RESULT IN A BOOK. I CAN HELP IF NEEDBE,

Thanks guys for the quick response and all the info.

First sunny morning in a week, so a boost to moral and motivation for sure.

I’ll do a more detailed cross-section sketch of what I’m thinking later, so that it will be easier discuss the different parts of the construction and approaches to layup.

I’ll put together the info I’ve gathered in a folder like you said. Think that’s a great idea. Always appreciate the knowledge we can gain from these forum discussions, but sometimes the info and technics can become difficult to find in long treads. Consolidation Could really help others in the future.

Will be back with more. For now we’re going to try and lock down definitive time we can pour this foundation, so we can move on to the next step of the build.

Cheers, Peter & Co...⛰🐕👨🏻‍🦱👩🏻🐕⛰

Party at the house!🤓

Wow Peter;   From picking a dry day to pour a foundation... to having a dance party!
What looks to be a big dance party ....in what looked to be a nice new tiny house!
Amazing how much room those tiny house must have inside!

thomas rubino wrote:Wow Peter;   From picking a dry day to pour a foundation... to having a dance party!
What looks to be a big dance party ....in what looked to be a nice new tiny house!
Amazing how much room those tiny house must have inside!

Mr. Gulch!

We sent you the invite. Was sure you’d be here, in some shiny new clogs, dancing the jig. Must have been so busy with that 6 minute doohickey, you complete forgot to RSVP...🔥🕳🔥

🪐😉🪐

Something like this...☮️

Working out these sonotube footers for the front posts. Can’t wait till this parts over...🙄

Hang in there kid! Been there done that and know the feeling quite well. When the forms start coming off and the back fill begins, the corners of the mouth start to go upwards!

Gerry Parent wrote:Hang in there kid! Been there done that and know the feeling quite well. When the forms start coming off and the back fill begins, the corners of the mouth start to go upwards!

Yeah! Trying to come up with a jig system to get those things in the “right” spot on uneven ground was a challenge. I just keep repeating, in my head, “square, plumb, and true... convincing myself that I should have a laser level etc etc...

Then I watch a Primitive Technology video, where the guy makes a house using a sharpened rock and a bamboo stick, with no shoes on.

Perspective...☮️🙏🏾🙏🏼🙏☮️