The Druid's Garden

Spiritual Journeys in Tending the Land, Permaculture, Wildcrafting, and Regenerative Living

Building with Cob, Part I: Project ideas and Honoring Earth September 1, 2019

Making some cob!

Connecting with the earth can mean a lot of things–and today, I want to talk through how to create a simple building material that can be used for a wide variety of purposes: cob.  Cob is an ancient building material that is a combination of sand, clay, and straw (or other strengthening materials) mixed with water. Cob, the synthesis of water and earth, becomes the passive forms through which we shape anything from a small earth oven to a whole living space.  In this post, I’ll introduce cob and offer some different kinds of projects that you can do with it. This post compliments last week’s post, where I shared how to make ecobricks from waste plastic materials.  Cob is certainly one of the more sustainable and local construction materials to use in conjunction with ecobricks, so I thought it would be a nice time to introduce this as well.  I’m also going to be doing a variety of cob projects on the homestead in the next few years that I will share about, and thus, it is useful to have this introduction first!

 

For many years, when I was studying natural building and various kinds of sustainable living at Strawbale Studio in Michigan, I offered a series of posts on natural building topics and rocket stoves. This post continues that series, and I am delighted to revisit some of these construction techniques. This post will serve as a basic introduction to natural building with cob–for more resources, there are books and classes (I’d highly suggest one of the internships at Strawbale Studio for a hands on experience!) Today’s post covers the preliminaries for cob building – what cob is, the kinds of projects you can make with cob, and the spiritual implications of learning to work with this amazing material. Next week’s post will show you how to test your soil and make cob.  Once I finish it in a month or so, I will also show the cob/cobblestone build a simple passive solar greenhouse heatsink wall.

 

Connecting to the Earth

Cob is the combination of sand, clay, and straw that has been used as a building material throughout the ages.  It is a most ancient building material, an ancestral building material.  It is always a local resource that reflects the different qualities of the earth in that location. It has been created by humans for thousands of years (if not longer), and is used in a number of building techniques, including adobe construction, waddle and daub construction, strawbale construction, and much more. In fact, nearly every temperate or tropical non-industrial culture has created their own version of cob in some capacity. This is a building material that is right from the land, created with our bodies in perfect harmony with the living earth.

 

In modern industrialized cultures, we often live in and build structures in opposition to the land. These structures almost always ignore basic things like sunlight, wind, or other weather patterns that would make heating and cooling them more effective and instead, rely on unsustainable fossil fuel burning to make them comfortable.  We live in houses full of toxic substances: the materials were toxic to the land and her peoples (human or otherwise) during extraction, toxic during their production, and they will be toxic when they are destroyed and put in a landfill. Our homes, structures, and building materials are thus in a constant state of disconnection from the living earth.  I think its hard to live that way, even subconsciously, and not experience some disconnection as well.

 

Cob offers us one path, of many, back to more nature connection.  Learning some cobbing and other natural building skills can help us connect with the earth, honor the earth, and learn some of the deeper mysteries of the land.  We can reconnect with the wisdom of our ancestors, who built shelters and homes right from the land aroudn them.  Learning to make cob, even through small things like making cob candleholders, allows for that deep, ancestral connection.  There is nothing as satisfying as communing with the earth, digging up some of her subsoil, sifting it, and stomping it with your bare feet to mix it into something that you can use to create virtually anything!   The mud between your toes, the weight of the earth, the shape of it in your hands–it is empowering, it is connective, and it is soul-filled.

 

Making cob and building with cob (also known as “cobbing”) also offers powerfully to the druid elements (which are explained here): particularly, the synthesis of gwyar and calas. You can also think of cob through the classical elements: the passive elements of water and earth are combined to build structures which heat, shelter, and allow us to cook meals, and so on.  It is an incredible and beautiful way to learn to live more in harmony with nature.

 

In the 21st century and the age of the Anthropocene, I think we need multiple pathways to find our way back to the cradle of the earth.  To a place of connection, or re-connection. Of learning that the earth, right under our feet, and the living things around us can truly provide all of our basic necessities for life.  This is a lesson that humanity has forgotten in the century+ past industrialization, but it is time that we begin to learn this lesson anew.  And for some of us, this lesson comes in the form of learning to build as our ancestors did–of using materials right from our land.

 

What are the benefits of working with Cob?

The Strawbale Studio - Cob/Strawbale with Thatched Roof

The Strawbale Studio – Cob/Strawbale with Thatched Roof

Local and sustainable sourcing, ethical building material. Because cob is locally sourced, it is an extremely sustainable building material. If you have the right kind of sub-soil, you can literally dig it out of your land and make it right there. Some sub-soil may require off-site amendments, depending on the nature of your soil (see soil tests, next week’s post). Cob comes right from the earth, and can return right to the earth, with minimal to no ecological impact. For example, in digging my hugelkultur beds, I replaced hard packed clay with large amounts of wood, plant matter, and compost–and the clay that was removed from those beds was piled up nearby, ready to be turned into cob.  Now I have a giant pile of subsoil that I am slowly using for new cob projects.

 

By comparison, modern construction materials are just awful from an environmental perspective. For example, the production of concrete is the *third largest* producer of C02 in the world! The link in the last sentence shows at how many different stages the production of concrete is linked to C02. Yes, concrete is more permanent than cob, but it comes with serious disadvantages.

 

Endless possibilities for construction. The possibilities of building with cob are endless! You can build earth ovens, chicken coops, candleholders, and even whole living structures. About 10 years ago, strawbale/cob construction was listed in the International Building Code, which makes it easier to secure the necessary permits in places that require them. Most of the “finished” photos in this post are from the Strawbale Studio, built by my natural building mentor, Deanne Bednar.  In addition, unlike many conventional building materials that require squares and rectangles, cob also allows for amazing amounts of versatility and creativity.  Unlike regular structures built with straight lines, cob allows for flowing curves, circles, spirals, and many unique features. Thus, many natural building projects are flowing, curvy, and fun.

 

Accessible to everyone. If you didn’t grow up “handy” or had someone to teach you, traditional construction may be inaccessible–both because it requires a lot of specialized knowledge and also because it requires multiple kinds of expensive tools and supplies. By comparison, cob construction can be taught to anyone, including children. In fact, cob allows us to build things right from the land, on the land, with minimal hand tools and no fossil fuel demands. It is perfect for group settings, schools, and other places where people want to join together to do something fun.

 

The inside of Strawbale studio with curves and beautiful features

The inside of Strawbale studio with curves and beautiful feature

Building with cob is “slow” and “meditative.”  Taking fossil fuels out of the equation requires a different kind of time commitment. Fossil fuels allow us to radically increase the speed at which things are done, but not the quality by which they are done.  Cobbing allows us to slow down, to re-attune with earth’s rhythms, and to have fun making something magical with our own hands and feet!  This is “earth time” and requires us to simply embrace the experience. Creating and working with cob is not done on “fast time” but represents a very slow and meditative process.  I list this as a benefit because I truly believe it to be so–by attuning with the earth and her building materials, we are forced to slow down, breathe, and be a participant in the process.

 

Can be combined with other sustainable practices. Cob is but one of many different techniques that can be used to build material. Timber framing, ecobricks, thatching, passive solar, rocket stoves/energy efficient heating, and shingle making from wood are just some of the strategies that align with these approaches. A rich universe of knowledge awaits you down this path!

 

Example Cob Projects: Rocket Stoves, Ovens, and Structures

One of the first considerations when thinking about a cob building project is matching the cob project to your climate. In arid climates where there is little rain, cob can be out in the sun and elements unprotected with minimal damage. In temperate climate with lots of rain, sleet, hail, and snow, special considerations are needed to protect the cob from the elements. In particular, cob designs need to have a “good hat” and “good feet.” That is cob projects are required to have some kind of protective structure that prevents the cob from getting wet–even with a finish plaster, it cannot stand up to the regular elements for extended periods.  A good footer,  usually made of stone, is what you rest cob on (so that it can’t wash away). This is one of the big differences between concrete and cob. Concrete is designed to stand up to the elements for years–but it also means that it will not return easily to the earth. Cob requires more TLC with regards to the elements, but is perfectly fine when designed correctly. As you see some of the examples of cob projects, you will see the use of the good hat/good foot design!  With this in mind, let’s explore some of the wonderful projects you can do with Cob!

 

Cob Ovens for Pizza and Baking. A staple in the cob world and a project that can be complete over several weekends is a cob baking oven for pizzas.  This is a good beginner project for cob, and there are lots of designs and resources online and in print.  I’ve built a few of these and have also had the pleasure in cooking in them!  The pizza that comes forth from them is amazing.

A cov oven at Sirius Ecovillage

This first photo is of the cob oven at Sirius Ecovillage (where I was blessed enough to do my permaculture design certificate in 2015!).  I love this oven because it has a well-designed structure that lets light in, it has beautiful artistry of the oven outside, and it produces quite tasty food!

 

Cob oven with fresh mushroom pizza

Earth Oven at Strawbale

This second oven is located at Strawbale studio.  While this oven was built before my time there, I was able to help repair cracks in this oven and bake in it on several occasions.  This oven did not have the optional stove pipe (like the first one did) but it still worked great.  In this case, the venting of the heat and smoke just come out the front. Notice the “hat” and ‘feet” of this design. The first photo shows some handmade pizzas with fresh foraged mushrooms we made and enjoyed as part of a workshop!

 

A Cob Rocket Stove or Rocket Mass Heater: Cob is excellent at transmitting heat (or cold) and because of that, it makes an excellent material for a rocket stove or rocket mass heater. There are lots of different designs for these; some years ago I detailed one rocket stove using a cob mortar here that I built with a group of others at Strawbale Studio. Other designs include indoor ones that are designed to heat larger spaces, like this other indoor heater at Strawbale.  This cob bench works on the principle of heating bodies, not spaces, so it radiates heat out.  It takes a long time to heat up (about 4 hours, as the cob is 4″ thick in most places) but even after the fire dies out, it will stay warm for many hours.

Indoor rocket mass heater

Indoor rocket mass heater at Strawbale Studio

Rocket stove with cob mortar

Rocket stove with cob mortar

Larger Structures: Buildings, Walls, and More: Cob projects can become any size you are willing to work on–up to full size houses, saunas, chicken coops, and more. Strawbale Studio has a lot of such examples of these kinds of structures. One of the keys to thinking about larger structures is that cob transmits heat or cold really well–this means that a stove will move heat outward. However, uninsulated cob walls will quickly turn into a freezer in winter–this is why cob is often combined wtih strawbale construction for strawbale’s insulation properties in temperate climates.  Cob on its own has no insulation and will move heat or cold through it.

Hobbit Sauna

Hobbit Sauna tree (this is a tree I designed and created for the sauna with help from my friends!  Here, the tree is drying after working on it for two days. This was done during my last visit to Strawbale Studio in 2017!)

 

In Greenhouses and as Heat Sinks.  My current in-progress cob project (which I should finish by the end of Fall 2019) is a cob/stone wall for the back of my greenhouse.  I am doing this project in my small repurposed carport greenhouse. All greenhouses have three sides that allow for light and heat to enter (east, south, and west).  The other side of the greenhouse, north, never has direct light or heat coming through it, and thus, it is better to insulate it than to treat it like the other three walls. Because cob is an excellent conductor of heat, I am using the wall as a heatsink. This will be useful for any sunny day in fall, winter, or spring where the sun heats the greenhouse up considerably but the temperature drops a lot in the night (in summer, sinking heat isn’t a problem!).  I’ll share this design in a future post.

 

Cob benches and smaller structures. Cob is also used for a variety of smaller structures, such as cob benches. These can be done indoors or out. I haven’t yet worked on one of these projects, but you can see nice examples here.

 

That’s it for today–in my next post, we’ll look how to test your soil for an appropriate mix of clay and sand, mixing cob, and doing some basic construction (in this case, my cob greenhouse wall). May your hands ever be in the earth, may your heart ever be full, and may your spirit ever be inspired!

 

The Samhain of our Lives October 28, 2018

Just last week, we had our first hard frost. After homesteading for a number of years, you grow to be vigilant for the signs of the first frost. The air smells different somehow in the two or so weeks leading up to it. The bird and wildlife patterns change.  The nights have a crisp bite to them that they didn’t even a few days before. And then, just like magic one day, the frost is there, glistening in the morning light. The garden radically changes overnight–even for those things you covered–the entire landscape lies in disarray.

 

Sunrise at First Frost

Sunrise at First Frost

I could feel it on the air, and for the last few mornings, have been going to to see if it had arrived. That morning, I turned the corner and first saw it first on the strawberry patch–white and glistening. The frost is beautiful, magical, and yet, destructive. While the garden was growing powerfully the day before–with the last harvests of our remaining tomatoes, eggplant, beans, squash, and gourds all ripening and growing abundantly–this morning, frost covers all.  By mid-day, the garden of yesterday is but a distant memory. The garden of the frost is a disaster zone for summer crops–the tomatoes are wily, the half-ripened crookneck squash spongy on the top where the frost hit, the eggplant fallen over in sadness.  By the second day, the leaves of these plants are withered and dead, former husks of what they had been less than 48 hours before.  The first time you see this destruction, its really something to behold.  It is shocking in how the cold can do so much damage in such a little time period by a temperature difference of only a few degrees.

 

Samhain is certainly here, and already, my garden has gone through increasingly hard and bitter frosts. The temperatures continue to plummet, the leaves drop from the trees, the animals and birds fatten up, hibernate, or fly south–and winter sets in.

 

This year though, this Samhain, it seems a little different. Maybe its the general collective despair and demoralization present right now, at least here in the US, which is affecting so many (and what I was responding to in my post a few weeks ago). Maybe its the latest UN report that suggests that–if we are lucky–we have about 12 more years to stave off the worst of climate change, but only if we act now. Maybe its reading that report and knowing that action, at least in my own country, won’t happen.  And, knowing, I will have to live to see the results of inaction, results that will irrevocably harm the live and lands I hold sacred. Maybe its the growing open conversations I am having with my new college students about their own futures and their fears.  I’ve been teaching college for over a decade, but it has only been in the last 1-2 years that I’ve heard my college age students start to openly discuss these things and their impact on their futures.

 

This Samhain, the changes in the landscape and in my garden, seem to reflect the changes going on culturally.  We’ve had more than a few hard frosts.  We’ve had bitterly cold days.  Some of our favorite summer plants are dying off. I think a lot of people are asking–is this a sign of things to come?  Are the darkest times, at the Winter Solstice–still to come?

 

Kale loves the frost!

Kale loves the frost!

In my frosted garden, I turn my eyes away from the summer crops, the eggplants, squash, and tomatoes that cannot handle even a 33 degree night with cover. Instead, I look to the carrots, onions, spinach, lettuce, celery, kale and cabbage that we had planted in late July. These plants are much more resilient, and all of them are doing fine despite the glistening of frost on their leaves. Some, in fact, had been enhanced by the frost–the cabbage leaves are more succulent, the kale more sweet. Rather than harming the plants, the frost had simply made them better versions of who they already were. This, too, seems to be a powerful lesson, both for the garden and for our larger culture.

 

It seems that I’m not the only one smelling frost on the air more culturally, and processing what to do about it. A few days ago, I saw a new thread on a permaculture forum written by a 22 year old girl who was asking serious questions: “Given the state of the world, do you really think permaculture offers us what we need to save the world?  If the older leaders refuse to act, can individual action save us? And if you are using permaculture this way, how do you stay focused when all of this is happening around us?” It was a good question, a reasonable question, and had a range of useful responses. One of the most powerful responses was from a man who had seen a world war, had worked industry, and had retired to a little one-room cottage in the woods. He shared some of the things he had seen in his life and said, “Its the cycle of life. The reason we practice permaculture is that it gives us hope. This is a season, others will come and go. I always ask is how do I respond.  And my response is to hope.” I wonder, too, if that’s why so many of us practice druidry.  It gives us connection, it gives us peace, but most of all, it gives us hope.

 

The practice of druidry, of living by the seasons, helps me process the inevitability of the crisis of climate and culture that seem to be bearing down at present. Samhain is in the air, both for us this year, but also for us culturally.  It might be that this time will pass and spring will arrive quickly.  Or, it may be that the world will have to endure the difficulties of winter, for some time to come.  Most of us think, or already know, that we are in for the latter, but I must remind myself of all that I learned as a druid gardener, all that I learned from celebrating the wheel of the year is present here this Samhain.

 

So much wonderful food in the greenhouse!

So much wonderful food in the greenhouse!

As a druid homesteader, I respond to the frost–and the incoming winter– by good planning and good design. The “problem” of winter  becomes a “solution” if I simply plan accordingly. I choose my plants more carefully for the fall and winter season–knowing some are resilient and designed for the cold, and others, like the tomato, fall at the first brush with frost.  I start these plants in July, when summer appears to be endless.  But soon enough, the fall will come, and these plants will thrive.

 

Using shelter and layering, the plants can survive much more than a bit of frost. Our little greenhouse will have a third layer of protection this wee, and our spinach, lettuce, bak choi, and arugula will be able to be continually harvested till January or later. Carrots and potatoes will stay in the ground waiting to be unearthed anytime the ground is unfrozen enough for us to do so. The greenhouse itself, combined with a second inner hoop house and then a thick floating row cover offers shelter. Embedded stones and a back covered wall allow the design of the greenhouse to be even more resilient, pulling in the warmth into the stones when the sun is out. The stones radiate that heat into the soil in the cold nights. Nothing will succumb to the frost or cold in that greenhouse unless it goes considerably below freezing. And if it does, we will make our final harvests, put wood on the fire, and wait till mid February or early March when the soil to warm enough to plant again.

 

Further, as a druid gardener, I think about the “problem is the solution” from the permaculture principles.  With the right plants and planning, we can thrive and grow.  Our world *needs* to change. The current course of our society is radically unsustianable, and every bit of communication from this wonderful earth is letting us know that with in creasing frequency.  Finding new ways to live, to be, to inhabit this world will require us to adapt to the harsh realities that Samhain brings.  We can’t be tomatoes in the coming years to come: we must be kale, cabbage, carrots, tatsoi, arugula, spinach–all of the plants that can withstand the harsh winter and still offer abundance.

 

As a druid, likewise, I have many lessons that help me think about and process this difficult time. I have celebrated the turning wheel of the year and the seasons for many, many years. I know that looking to my ancestors and honoring the season in the moment brings me quietude and peace.  I also look to my ancestors to re-learn how to live more sustainably and simply, in line with the living earth. I know that winter is coming, and it will be dark, and harsh, and cold.  But somewhere in my bones, woven into my DNA, I know my ancestors got by with much less than I did, and they thrived–if they hadn’t, I wouldn’t be here today.  I also know of the beauty of winter when it arrives; I know of the freshness of the snowfall and the cold nights where the stars glisten.  And most of all, I know that spring will come once again.  The maples will once again begin to run, the crocuses will once again bloom.

 

 

In the meantime, I’m going to shore up this greenhouse and plant more kale.

 

Repurposed Greenhouse from 9×18′ Carport March 11, 2018

I have always longed for a greenhouse.  As a homesteader in MI, I only had small hoop houses that I moved over crops, and while they worked great, they did not afford the flexibility that a larger greenhouse has.  When I bought my new property in the fall, I knew that I was finally going to be able to put up a real greenhouse! And so, this post describes the construction process of the greenhouse from a 9×18 foot used carport.  These instructions will include a step-by-step process for creating a hobby greenhouse using very lay-person’s terms, since that is all I have.  Two people built this project in a weekend.  This post will focus on the structure–I will have one post on bed preparation and insulation of the beds of the greenhouse to prevent frost issues, and a 3rd post eventually on the cob heatsink wall that I am planning for the north face of the greenhouse.

 

Happy Greenhouse!

Happy Greenhouse!

Used carports actually make wonderful greenhouses.  They are often much tougher than the commercial greenhouses they want several thousand dollars for–the carport is very solid and sound from a structural perspective and offers a strong frame.  We have had some 60 MPH winds come through here recently and several foot plus snowfalls over the winter, and my little car port greenhouse is in excellent shape.  My carport was gifted to me by my dear friend Linda from Nature’s Harvest Urban Permaculture Farm.  This was a greenhouse she used for several years  for seedling starting and when she was done with it, she passed it on to me.  I’ve carefully carried it with me through several moves and now it is in its permanent home!

 

I’m going to walk through the build for this greenhouse step by step. I had help from a friend who had some tools and framing knowledge–but we basically built the entire thing with four tools: a miter saw, an impact driver, a square, and a tape measure.  T

Greenhouse Site

Locating the right site for your greenhouse is quite important. You want it to have full exposure to the sun year round, depending on your climate and needs.  For my greenhouse, the exposure especially in the dark half of the year is important if I want to keep harveseting vegetables in the fall and have a safe shelter for seed starts in the spring.  Here is some good information on greenhouse placement that goes into more depth.

 

I was very lucky that the property I bought had an old flat pool area, very close to the house, that had full sun exposure.  I set it on an East-to-West orientation for full sun.  The spot also had easy access to power (an outdoor box), water (both drainage from the roof and a nearby hose hookup) and was in “zone 1” in permacuture terms from my main house.  Greenhouses need frequent tending in the fall and spring, so keeping them close to the house is important. With these things considered, we can go ahead and start to build!

Greenhouse Build

Step 1: Create a good foundation.  Since my foundation was solid clay and almost completely level, we began building the greenhouse by attaching the structure to lengths of pressure treated 4×4″ beams.  I was concerned that since there is wind here, the greenhouse would blow away.  We also wanted to keep the metal itself up off the ground to prevent any rusting.  We used washers and standard screws to screw the metal frame into the boards.

4x4" treated boards for floor.

4×4″ treated boards for floor.

 

Step 2: We used self-sealing metal screws to assemble the carport together.  This helped hold the metal together and solidifed the frame (since it was used, the original components for it were long gone!).

Assembling the structure with self-sealing screws and an impact driver

Assembling the structure with self-sealing screws and an impact driver

 

Step 3: Sealing any rusted areas. We also took some Rustolium and sprayed any areas that were a bit rusty to encourage the greenhouse to last.  They get very humid, so any rusty places will not last long. This is where I got introduced to my favorite tool ever, the Dewalt Impact driver.  It was very helpful for this project because I could put in many difficult screws (like metal to metal) with limited arm strength.

 

Step 4: Framing. For the novice buider, this is probably the most challenging part, but I had a friend who knew what he was doing. We began framing out the sides and planning a large door so that I could bring a wheel barrow in and out easily.  Large doors on both sides and windows also help with venting.  Here’s when we started framing it. All of the wood is pressure treated.

Framing out the sides

Framing out the sides

 

Both sides framed

Both sides framed

Frames secured with little stainless steel belt

Frames secured with little stainless steel belt

Step 5: Greenhouse Spring Locks.   After shopping around, I settled on these greenhouse spring locks that allow you to attach the plastic to the greenhouse. My carport had a nice ridge line across the sides about 4′ up, this allowed us to attach the strips there (using the self-sealing screws again).

Adding the strips for greenhouse plastic

Adding the strips for greenhouse plastic

Step 6: Back wall.  The north facing wall of a greenhouse is useless–it doesn’t transmit much light and it simply loses heat day in and day out. Many more traditional greenhouses, like those in use in China, use a back wall that is not exposed or that is sunk into the earth to preserve heat. My plan for this greenhouse is to turn the back wall into a cob wall that will gather up the sun’s heat during the day and release it at night. Cob is a natural building material that is a mixture of clay, sand, and straw (I have ample clay on this property, which is what gave me the idea).

 

In order to begin to prepare for the wall, we two boards up so that I had a good surface onto which to build my cob wall. We attached the boards right through the frame using more longer metal screws.

Back wall begun

Back wall begun

Step 7: Greenhouse plastic.  There are a lot of options for greenhouse plastic–I went with a standard 6mil clear greenhouse plastic.  It is really important to use the right plastic that is greenhouse grade–if you just use plastic dropcloth, the greenhouse will fall apart within a year or two due to the solar rays breaking down the plastic.  I learned this the hard way at my old homestead!

 

The second part of the spring lock system is a little black zigzag strip that is plastic coated.   I’d highly recommend them. They are super easy to use and if you mess up, you can just take the little strips out.  This part is absolutely a 2-person job; it is necessary to keep the plastic tight as you are adding it.

Laying out the plastic before putting it on the greenhouse

Laying out the plastic before putting it on the greenhouse

 

Strips and wire for holding plastic in place

Strips and wire for holding plastic in place; excess plastic was later trimmed off.

Step 8: Doors and windows.  I had chosen to add this some clear polycarbonate to the doors and windows–in truth, I regret that choice for a few reasons.   First, it is way more expensive than the greenhouse plastic.  Yes, it lasts longer, but it is much harder to work with.  Second, it is not sealed up nice like the greenhouse plastic–it is variegated, meaning each little dip is a little air hole in your greenhouse.  I am still figuring out how to seal them all up!  In hindsight, I would have went with only plastic for my greenhouse. But I attached them with special screws that have a little washer.

Variegated back wall

Variegated back wall

Step 9: Ventillation. I purchased these automatic greenhouse openers for the vents.  This is critical for  some automated ventillation, especially if I am out of town or at work and the greenhouse heats up.  You simply install them and they are designed to vent the greenhouse.  Unfortunately, mine don’t seem to work, so I’ll have to look into another option.

 

 

That’s it for the greenhouse build! In an upcoming post, I’ll share how do floor insulation and create beds and share my progress on the back cob wall.  I hope these instructions are helpful to anyone who might be looking for good greenhouse ideas!