 Hey, welcome to episode number 23 of the Low-Technology Institute's low-tech video series today We're doing a long overdue update on our wallopini, which is an in-ground greenhouse You can see some of the photos here during the summer and winter The backside is berm to earth and that helps absorb sun's rays And here you see some plants getting there Getting warmed up even in the winter The plan is available on our website lowtechinstitute.org and basically like I said It's an in-ground greenhouse and it takes advantage of the summer and winter sun With a slanted roof facing to the south It's built up of earth bags which are essentially clay filled Sandbags that form a retaining wall between each layer we have barbed wire acting as Velcro And we've also driven rebar through them to help make this a more stable wall From the top you can see it's an oval and the walls are bowed out to help keep the soil from pushing back against it We started this project in 2017 by laying out where we wanted to make this and we put it behind our garage So we had clear off the topsoil and the overburden because we didn't want the organic material into the backfill We laid out the corners using triangulation to get it square And then started digging our trenches and we did that all by hand and it took quite a long time I was able to move about six tons of earth a day And I made a series of piles around I moved the organic topsoil into garden beds So that I could get to the clay underneath each trenches bottom got gravel and drainage pipe to help move water away from underneath and then I added Plastic Barrier on the outside to further help keep moisture out of the walls as you can see here I dug trenches where the walls would be leaving the interior which would be open space as Filled earth and then that earth would be Turned into earth bags. I had to put up retaining walls out of wood to keep the back berms from Collapsing in on me while I worked Okay, I'm standing in my Foundation pit What's going to be the wallopini and I have to do a soil assessment to figure out what percentage of what I have in my soils And the way I do that is through a field soil test. Actually, I'm gonna use two different tests I'm gonna use a field soil test and then I'm going to use a jar test so I've got well. I really have three types of soil. I've already removed the topsoil which is highly organic Dark soil and you don't want to use that in your earth bags because The organics rot they don't bind to anything. They swell they shrink. They're no good. Then I have this a horizon which is a Clay type of soil. It's quite dark It's got some soil in it or some Chickens are interested. It's got some organics left in it So what I'd really like to use is the next layer of soil which goes Let's see. We've got about one foot of this a horizon dark Clayish soil and then below that we have like a brownish soil that is also clay But seems to be a lot higher clay content. It's very very sticky So I'm gonna get a couple samples of that and I'm gonna run through the field soil test and then I'll put some in a jar here to do the The flotation soil test So I want to get a Good handful like it says 25 grams. I don't know the size of a golf ball Maybe a little less than a golf ball and it's damp already, but I'm gonna add a little water So it's just a little wetter Mix that water through there. This is a fun activity for kids Very very sticky. So now I'm gonna go through basically a checklist or a flowchart to figure out what type of soil this is so first Does it ball when squeezed? Yes, clearly if it didn't And it wasn't too wet or dry than it would be just pure sand, but since it balls I'm gonna try and roll it It to see if it makes a snake And how long that snake is before it breaks will tell me what percentage approximately of Sand and soil Sand and clay and silt are in here and since it makes an unbroken snake really It's gonna have a high clay content, but really it's very very clay so I would say this is between two and a half to five centimeters so that means it's a Got some loam in it and now I take and I run it between my just a little bit between my fingers And if I feel any grit, then it's got sand in it. I don't really feel much grit It doesn't really feel very smooth And so this is probably gonna be something in the order of clay loam Yeah, there's almost no sand in it so now what I'm gonna do I'll just do the same thing with this dark Black clay because I really like to have something with a sand content in it I'm afraid this has too much organic in it. Unfortunately So let's see if I can work some water into this because it's way too dry to test No, it's also very smooth So these are probably both clay loams since they're so Or even just straight clay Probably loamy clay is really what I'd call them But to find out for sure I'm gonna dump out half the water in this and Fill it with the brown soil and shake it up quite a lot and that will Settle out over the night. I'll set it on a counter. I'll let it settle out and by tomorrow We'll be able to see if there's any sand in it but I I don't think there is which may be a slight problem or Something we're gonna have to take into consideration. We're actually building the earth bags more of the brown The problem with clay is that it swells and shrinks Depending on its moisture content So you don't really want that if you want to build a stable earth bag wall you want it to not expand Because if you want to put plaster on it that would destroy your plaster you want 70 to 80% sand and 10 to 20% Clay and then maybe some hydrated lime because of the clay content Which is kind of what we're shooting for so let's get this fully mixed up And the chickens are super interested because it might be food It's not girls So that is as mixed as it's gonna get and now I'll go put that on the counter and Inside and by tomorrow it'll have settled out and we'll see how much clay and other components we have in this soil Unfortunately, it's gonna be a lot of clay Which is gonna be slightly problematic But since I don't plan to plaster the walls and I plan to keep it fairly dry Through some impermeable men and brains. I'm gonna probably just have to live with Getting away with or trying to get away with a high clay content in my soil. Unfortunately, and we'll just see how it goes And here you see the clay not expanding when it's placed in water Which was really lucky for me because you can't use expansive clay in earth bags The time-consuming part of the project was really mixing the soil that would go into the earth bags Which was again about two parts clay to one part chopped straw to quarter part hydrated lime This would all get mixed together Which was kind of a back breaking and laborious process This fill would then get put into buckets and those buckets would get dumped into the bags Which are held up by these little Wooden frames that we could clamp them into here. We see just this you know repetitive process It was 500 earth bags that I filled in each one took me a few minutes to mix and fill in place It was a long time-consuming process And once these bags were filled the ends would get folded over and they would get laid down Flat and tight next to their neighbors I would stomp on them to help Compact them and then later I would go by with a tamper and really ram them as flat as I could Because if you didn't they would later settle and make things uneven and unstable You can see the plastic on the outside on the left there keep things as dry as possible the bags themselves also had liners I got all these bags from Wisconsin Brewing Company and and the Hophouse Brewing Company They had hundreds of these left over from their brewing process and they were nice enough to save them and give them to me I had to go by each week to pick up Hundreds of these bags. It was another time-consuming process Also, thank you to the volunteers who came out in 2017 to help do some work on a cold fall whole day mixing up refilling and Laying it out earth bags. It was a kind of fun process to have help with In 2018 I put the roof on in the spring so that I could work in there a little easier So this is a freestanding roof. It's actually not reliant on the earth bags for support. Although they are tied together They are 2x6's on two-foot centers. It's not As robust as it could be but it does do the trick and then there was a laminated Polycarbonate roofing over that this allowed me to work a lot faster inside because I had a lot more space And the earth bag wall grew up very very quickly At least it looks very quick in the photos, but it was a lot of time on my part I got the front half done and then moved on to the back half in 2019 this is a Project that I would do when I had free time, which isn't that often I was able to finish the back wall in 2019 just in time There's the last bag being put in place just in time for the 2019 skill share that we did I also reinforced these walls by putting cables into posts that were dug into the earth beaten into the big earth berm behind And that cable helps ties the wall Together and keep it from caving in then I used extra earth bags to help move water away from the From the structure by attaching them here to the frame and then sloping them away All right, I got the interiors to this point just in time for the 2019 skill share when we had a mason come out to help us create a Mass heater which would be what keeps the Wallopini warm in the winter and this was Jim Chalice from tall grass hearth and home Now you can check out his website tall grass hearth and home comm and here you can see his design that he made and sketch up with the small inner firebox and smoke and chimney and The outer box that would actually heat up with the kiln lid on top and here's the exterior smokestack so I had to lay a foundation and Fire bricks for the firebox Jim did this with the help of students in a class that he taught in 2019 This was all built in a weekend, which was a pretty amazing thing to see come together Here you can see the inner firebox being built With the exterior skin That would absorb the heat and so the idea of a masonry mass heater as I'll explain later is to basically Absorb a lot of heat and all this mass and then let it dissipate over time and here. I am learning to butter The bricks before putting in place and here we see the inner skin being built By a series of volunteers and here we have our littlest volunteer my son who is taking a nap while I helped the Interior so yeah, there he is in the background and here we have the finished interior layer And now we have to do a second skin on the outside Separated by a small air gap this just all adds to the thermal mass of the unit on top We have kiln lids and they are bearing the brunt of a lot of the heat And here it is at the end of the skill share and I had to complete the last few courses After the class was over on top There was a little bit of insulation to help keep the heat down in the unit and here we see the final unit completed We still need to put plaster on the outside, but I haven't had time to do that yet The smoke coming out is not that hot I can touch the smoke stack Because most of the heat is kept inside Well, it's winter Obviously, it's actually New Year's Eve and I'm out here in the greenhouse. I've been burning our stove This thing is nice and warm to the touch It's keeping it. Oh right now. It's 51 in here, but we've had it up to 60 And I'm definitely keeping it nice and toasty so that I can finish plastering the walls in this greenhouse So let's close this up So it runs more efficiently and Let's get plastering in the middle of winter and now I'm starting to mix up DAWB and this is three-part sand two parts clay one part chopped straw The idea of this is basically a clay plaster that gets shoved on to the walls to cover them with the initial coat It's helped to be held on by a series a layer of chicken wire That's been attached to the earth bags. You can see in the background there the the finished DAWB with the earth bags and the way that I've been mixing it is by putting it all on a tarp and then Mixing it together. I start with the clay and the sand to get those well mixed and then I add the chopped straw This is a time-consuming process It takes twice as long to mix it as it does to apply it to the wall And really it's just a series of stepping it folding it over kind of kneading it And I could do it with my bare feet, but again, it was winter and you know 50s in there So it's much nicer to do it this way. I keep myself relatively clean Instead of getting completely caked with mud and muck The final product is then put in a tote that I can move around and And then I start pushing it into the walls and it's nice to wear gloves because you can catch yourself on any loose ends of the chicken wire And also just because It's cold and wet. I was able to wear rubber gloves underneath the work gloves and over time You can see I just cover every bit of the earthbag walls with this cob and then I let it dry I then had to bring in hydrated line. This is type S Special masions lime that when hydrated becomes lime putty, so I'm bringing in about 500 pounds of it here One snowy afternoon 500 pounds hydrated line in water This hydrated line is caustic and if you breathe in a lot of the dust it can be So I'm dumping into a 50 gallon drum the top cut off that already has water in the bottom And I ended up using I forget the exact ratio, but it was about a Jugger to her Perf bag and then I mix it with the egg beater This is another time consuming process And much easier for the power tool if you have access to it you need a strong drill a handheld Typical household drill won't do this you need a You And then I smooth it all out and cover it with a layer of water so that oxygen doesn't get to it because once oxygen Gets the lime putty it starts to turn it back into calcium carbonate type Limestone essentially I Then I have to mix up the lime putty into plaster where I'm using three-part sand to two parts putty And I did mix it on the floor again, and this is okay But as you'll see here in a little bit It's actually much better to mix it in a tub, but essentially it's the same process as mixing the dob Never mind my son in the background blowing raspberries. That's just how it works out The traditional Fibers horsehair I'm fresh out So I'm using this this is Leftovers from when I was making linen. This is toe. It's used to make into rope for for pulling Things along barges and such, but it also works really well as fiber. So so I got this nice Very nice strong fiber linen fibers from the flax plant. It's very strong So I put about one part of this for every part for every part of lime putty I put one part of this so Here I'm putting three to one sand to putty plus one part hair and Now I'm finding I'm adding a bit of water this hair. It's pretty dry So I think it was suck sapping some of my moisture my workability So there's about a gallon's worth Now I'll do up another gallon if you've got a high-power drill is a seven amp drill and You want to mix up some Some lime putty and sand this With an egg beater It's a huge time saver. I just mixed up this this load here with three gallons of lime putty and five gallons of sand with I Don't know five minutes of this And scraping down the sides, which would have taken me 20 minutes by stomping it and flipping it in the In the tarp. So if you have access to this check out if there's a tool library near you Or your neighbor has one or you know pick up one yourself used or something like that They're not that expensive and huge time saver if you're doing a big a big project like this Trying something a little different. I've got that side done with my three coat plaster And that's drying out now, and I'm gonna whitewash it but here I'm doing basically the same thing except I'm putting on a harrow coat Harrow or a hurl is literally thrown on the wall But since I don't have a harrowing trowel which looks like kind of like a small shovel Then you go flick and you flick it on and it's awesome If I think about it, I'll put a link to the video that does it here in the corner But since I don't have the option to do that I'm putting it on with a trowel as best I can like a harrowing coat and then I'm scraping it here with a Trowel so that it has lots of good Fingers that the the next layer can key into so we'll see if this makes any difference because this surface this cob surface is a Little friable. It's not necessarily the strongest best backing to be really pushing into For plaster so I'm gonna see if this turns out any different than that side over there Maybe I'll let them sit all summer and see which one holds up best and then I'll do the rest of it that way That might be one way to go about it, but The plastering continues It's very wet, but that's what a harrowing coat is supposed to be Now it's a few days later, and I am brushing this harrow coat With a masonry brush dumped in water Because I want to both wet it and I want to get off any friable bits that don't stick At the meantime, I'm mixing up three to one mix and I'm being as diligent as I can to stick to three to one because I think Some of my I'm getting some cracking issues on my plaster I put on before and that's probably because I Wasn't able to keep a three-to-one coat I was closer to two-to-one so that was too fat as they say But I just want to get this nice and wet so that It doesn't suck all the moisture out of my coat that I'm gonna put on the scratch coat And I'm doing this about an hour before I anticipate an hour or two Before I anticipate actually applying anything so that this can soak in and then right before I apply it I'll do it again maybe not this aggressively wet but Let's let this suck all the moisture in and then we'll get to putting on the scratch coat Okay, well, here's that harrow coat With the nice keys in it and it's set up nice and nice and stiff. I've been wetting it and now I'm gonna take the Three-to-one so three sand to one putty to one fiber Coat that I've made or Plaster that I've mixed up and I'm gonna spread that on the wall I had to add a little water because my putty I think was a little dry and the sand was a little dry so this is 350 pound bags of sand so that gives you an idea of how much I'm using here It's 150 pounds of sand. I've already done one three by Six panel and so I'm hoping I'll get this remaining six by six area done with the remaining sand Hopefully because then I can continue building on more fun more fun greenhouse installation stuff So this is my hawk. It's basically a little platter for holding the Putty the plaster so I get two scoops Here with my flow trowel And I've learned after reading and watching instructional videos and talking with Some people who do this more professionally than I do This helps plasticize kind of get it membered up Find the wall. I just wet my wall a minute ago. I wet it this morning now. I just remisted it So it's nice and damp There's no standing water on the surface And then like before where I start at the bottom. I'm actually gonna start at the top And do a band across the top and unfortunately my wall isn't smooth or flat like a brick wall It's got some undulations. I've leveled a lot of it out with the cob But it's a little more difficult to do an undulating wall So, you know, I'm learning to plaster on a more difficult wall So maybe someday when I do an actual flat wall, this will be easier And I'm gonna use the flick and spread method I could scoop it up and spread it, but I'm just going to fling globs on the top here and then Then spread it I've used both ways. I enjoy this more. I don't know why and I close my eyes As I do it because I learned the hard way of the day with harrowing Always wear safety goggles and my safety goggles are inside. I'm gonna go for about a half inch thick So this is the haul coat and then we've got the scratch coat It's called the scratch coat because then you scratch it I've just got a piece of wood with some nails on it and basically I'm just putting in some striations So that when I put the brown coat on the next coat, it'll really have Gaps and little bits to dig in there. I don't want to go through the coat. I just want to Scratch the coat Nice and evenly give it something to hold on to do I want to do you can do like I've seen diamond patterns like this very nice Primarily though, I see just horizontal lines Because the thought is Horizontal works better because it's you know, not gonna fall down, which is the direction. I'm worried about it falling All right, I've definitely seen some that go like this But again, the majority I've seen do something about like this And it's not even Evenly poking through because I have an undulating wall if you're doing this on like a brick wall it would work a lot better Well, it's now a few days later and as you can see this is set up pretty nice It's actually pretty hard and no cracks unlike Before I had the problem. I wasn't able to get this wet enough because my putty I guess didn't have enough moisture and so I ended up adding more putty and I was cutting down my ratio so it was more like two sand or one putty and then it would crack a lot because What happens here with three sand to one is inside all of this all the sand and the grit can touch each other Right so it's pushing against each other and then the putty is in between think of it like a bowl of marbles and then I pour Something liquid between those marbles. There's plenty of space and so the marbles are touching and They create that lattice structure and then the stuff that fills in between them the putty in this case Holds it all together. So here look at this. No cracks and it's nice and hard So I'm going to go ahead and put my next coat of plaster on here after I wet it down And I could do three coats. This is my scratch and hair coat I I could do a three coat plaster, but you know what? This is in a greenhouse. It just needs to be a Decent-looking wall. It's not like my living room. So I'm just going to do one more coat Smooth it out and whitewash the heck out of it and it'll look actually pretty nice Now it's time to do some whitewash and whitewash is not just white paint Whitewash is actually lime putty with water and a little bit of salt and I added a little bit of powdered milk Because the casein and the white milk actually makes a more durable finish on wood So what I've got here is about one part lime putty to four to six parts water and maybe a oh An eighth of a part of salt just a bit of salt and less than that of milk And I've already been working on some of these in the background and these are getting their second coat now I'm also putting this on the walls and the nice thing about lime wash is when it dries It crystallizes and it has fast sets and it bounces the light everywhere So it'll make a much brighter interior than just paint wood. So that's what I'm up to now Lime wash It also comes right off the clothing, which is nice. I don't get paint flecks all over my beautiful work clothes here I