Ivar Oudewortel

Dear Permies,

I am planning an Off-grid hotwater shower build and I would like to share my idea in this group to see what you folks think of it.
I hope different eyes would give me maybe a better perspective.

The general idea is building a shower shed in a remote place without any electric current, plenty of pruning available fire wood as in logs not so much.
Hence the idea using a Rocket Stove to heat the water.

I have attached a schematic drawling of the installation.
Let me share some thoughts on how I got where I am right now because I have two question marks on which I would love your opinions.

Heating up water and mixing it to the desired temperature does not appeal to me because I don't want to run the risk anyone misjudging and either have a cold shower or worst burns.
In this setup I think I can do with ordinary valves and a mixer tap, easier to come by from scrap yards.
If the system is not used for some time its easy to drain it Almost no water in the system which stands still for a long time.
(maybe I should add a drain valve underneath each vessel to completely drain the system.  

The first question mark is using either a Rocket Stove or a "regular" stove or open fire. T
he pro's in my eyes are obviously that they burn so incredible efficient and we have plenty of pruning available on sight.
The con is that it would make the whole build a bit more complicated thus time consuming and if we heat the water with open fire or a "regular" kind of stove the shower area gets heated up in the proces.

The second question mark is either to place the hot and cold water vessels up high and have gravity run the water through the shower head. Which would result in a higher shower shed and need for heavier construction on at least that part. Or after filling both vessels and heating the hotwater vessel pump air on top of both vessels to create pressure beer keg style.
The air pressure pump handle should obviously be in the shower compartiment to add pressure when needed while showering.

I'm very curious what your comments are.
Thanks in advance and have a green day or twee.

Kind regards Ifar.

Slowly but surely progressing...

Thanks for the reply.

I did not use any fire bricks or whatsoever for insulation, I figured that the mass of the cob would do that trick since the base of the structure is at least 1 meter 20 by 90 centimeter.
I did use some bricks in the base to fill up space. Being a lazy cobber. Or efficient, I always mix up these therms.
Since the project is moving on slowly, each time I add a new layer I fill in cracks of previous layers. Most of them don't reappear after drying.
Haven't stoke fire yet so I'll see what that does to my cob.
I'll keep ya'll posted.

Kind regards from the Netherlands.

Gerry Parent wrote:Thanks for the update Ivar. The rebar outlines what you have in mind really well. I don't think you'll have any issues with it as its buried deep inside the cob.
As for air control, you could cob in a curved wall to fill in the gap below the grate, then cut a hole which could have a simple adjustable damper for those times you want things just to simmer. Something like a cob oven door but hinged or a slider plate if you want to get more fancy. Keep us updated as we all like pictures!

Thanks Gerry for the reply.
Would you have any suggestions on what the minimum thickness of the wall should be in order to be safe?
Normally I would think at least 30 cm but given the fact this wall is reenforced with rebar I tend to think that it could be a bit less tick.

Any suggestions on that?

Kind regards...

Dear permits,

With great amazement I watched the video on YouTube from Survival Skills Primitive where in 2 guys build a small home without any tools.
I guess most of you are familiar with these guys or kind of YouTube clips. Amazing as it is it raised one big question in my head.
I started searching the fora over here and I could not find an answer, I did ran in many likewise questions from other Permies users.

These guys in the mentioned video, I'll link below the message, seem to making bricks as wel as mortar from just limestone (after somewhat preparing), sand and clay.
No surprise there YET!
What amazed me in the video is that they are using this mortar with above mentioned ingredients for the roof aswel, mind you the top layer of the roof with just these ingredients.
They did add some fiber.

Judging by the scenery of the video I imagine in those parts of the world they are bound to get some rain at a given time, maybe even a rainy season.
Thats when I got baffled, does this mix actually provide a rainproof product to withstand dripping rain or at least a little short shower every now and then?
Judging by the amount of bamboo them guys have growing around Im guessing there a lot more then just a little rain in this area.

Or maybe am I too easy to fool in believing this could actually work.
And will this build be washed away by the first rain season.

Sorry long story, I was under the impression that building with Cob made it mandatory to use a hat and boots.
Have these guys found the holy grale in natural building?


Im so very curious what my fellow Permies think about this.
Cant wait to find your answers.
And bet your ass that I m gonna try this myself anyway, no matter what you guys say.

Video link:




Thanks in advance...

Be good, be safe.

Update some more pics.
After almost a year finally got some work done.

Just to be sure I added some rebar-ish metal I found somewhere. The idea is that it would probably give some more strengt in the wall because the desired shape I have in mind is some what bottle shaped. I want the wall to lean over a bit before leaning back in.
Since I had the rebar laying around I fiffured It would hurt to put it in.

If any one strongly advices against it for good reasons its not too late to take it out yet.
Given the pass of the building tempo plenty of time for that.

Another thing I wonder about is the bottom grid, an old table surface made of a fine mazed metal grid.
I put it in there to build the fire upon, below the ash collector area.
Also I thought that it would give the fire plenty of acces to oxygen for a good burn. Now I m thinking isn't it too much oxygen for the fire. In other words would it in this setting be almost impossible to make a nice and low fire for slow cooking purposes. given the fact that the fire can maybe too easy suck in all the air it needs for a big intense burn...

Maybe I should put in a cob slab with just some holes for air intake instead of the all area open grid.



Kind regards.

Ivar

Dear Daniel and John (and other permies)

Thanks for the reply, I have checked out the Rumsfort fire box but that doesn’t cut it for me.
The cast iron kettle is 40 cm in diameter and the grill grid is 120 cm x 60 cm. So the shallow fire box has to be at least 60 cm deep, inner size.
As you can see on the pictures, I have started the first batch of cob on top of the urbanite. I might decide to put some more cob on the wooden deck to ingrease the size of the of the actual pit, inner size.

That aside, my main concern stil is, the different expansion/ shrinking rates of the different materials I want to use in the cob wall.

Since glass and cob are both made of sand I expect not too much difference in those but still.

Daniel Ray, what a beautifull kitchen you guys made, big up!
Bit bigger of a project I have started but who knows in the future I might be able to pull something off like that.
Question, is the firebox below just heating the oven by radiation or are the fumes passing through the oven compartment?

I have made a temporary roof out of plastic because I ‘m not sure about the roof yet. I might opt for extending the current shelter roof.
I would much rather build it completely out of cob, chimney and all.
Hoping to seal the outside with boiled line sead oil for weather protection.
Given the fact it tends to rain quite a bit in the Netherlands that might be a bold or plain stupid choice.
It would look awesome though, even if its just for three years.

Ill udate when I’ve got some work done.
Pics are not spectaculair yet.

Thanks in advance.

Be good!

I know this tread is a bit old but I ‘m hoping someone still reads this sometimes. (As I did).
After a couple of days (and some nights below 0 degrees celsius)
The sample looked like the first pic.
It seems to me that there’s hardly any sand in this soil sample.
I mixed a batch of cob adding 5 buckets of sand to one bucked of this soil/clay.
Seemed pretty good cob to me, although I m not so much expierienxed in cob.
The hold of the mix was pretty good even without strawl.
See 2nd pic.

So my questions are...
1. Did I misread the jartest results or does my sample indeed have very few sand in it.
2. If so, should I add more sand to the mix to prepare cob for building.
3. What effect would a too high percentage of clay in the cob have on my fireplace build out of cob?

Thanks permies in advance, looking dorward to your thoughts.

Kind regards from the Netherlands.

I.

Dear permies,

I want to build a fireplace under an outdoor shed.
The goal is both open fire for Dutch Oven, cast iron kettle cooking and or bbq nights, you know, the good stuff.
On the end of the existing open shed, no walls just over roofed, this fire place is about to emerge.
The idea is to make a round-ish cob wall, place a roof with overhang on the wall and build a chimney on top of the roof. (Haven’t got a clue on the chimney construction yet, ideas are welcome)

Foundation is layed by some urbanite (smashed bricks) covered with cob.
Since the height of the wall is going to be close to 2.5 meters, I m going to need a fair amount of cob.
Reducing the total amount by adding bottles, cans or bricks in the wall is very tempting.
Since the cobwall is esentially a fireplace, pretty big temperature changes are to be expected.
Adding different materials in this wall, all having their own expansion/ shrinking rates concerns me slightly.
Especially given the fact that the wall is loadbarying for the roofstructure as well as a fair mass itself, I don’t want the risk of the walls falling down due to big cracks.
Hurting my toes or worse, spoiling my meal.
I can imagine that the base of the fireplace up to say 1 meter, takes the biggest temperature swings and therefore should be 100% cob. Above that I would love to use bottles and cans, even if its just for the beauty of the end result.

Hope anyone has some thoughts about this?

Thanks in advance and love to hear from you guys and girls.

Kind regards, Ivar

Hi folks,

Ivar from Arnhem here.
I just came back from Wageningen where a group of people living in a forrest as permie as they can.
They started building a earthship-ish struckture and my roll is building a Rocket Mass Heater in there.
Fantastic site and very challenging project for me aswelk hence its my first RMH I ever build.

Will post a link later with the building process documented.
They have a permagarden allready and live more or less independed / off grid.
Check out www.partijvoordeplanten.nl for some info about them.

As soon as I have a bit more time I will check out your projects too.

Saludos de Arnhem.