Mud for the People! Building an Adobe Garden Wall

This weekend Kelly and I had our first adobe encounter. We were lucky to have been invited to attend a workshop led by Kurt Gardella and Ben Loescher. Kurt also teaches both live and online classes that you can find out about on his website, www.kurtgardella.com. We’ll post announcements for future classes, because I haven’t had so much fun in a long time! This past weekend’s workshop focused on making bricks and building an adobe garden wall. If you want to learn about adobe, Kurt and Ben are the folks to go to. And, lest we forget, adobe is the traditional building material of the Southwest United States and many other parts of the world. Adobe needs just people power and locally available materials.

What follows, after the jump, is a pictorial essay of our adobe experience.

We missed the first day of the workshop, but pieced together what Kurt and Ben went over. One of the first steps is to determine the clay/sand content of your soil and to do that you do a jar test. When you mix some soil with water in a jar and let it sit, the clay settles on top, the silt below that, and the sand on bottom. You can measure the sample and determine percentages.

At the workshop, held in the high desert town of Landers, CA the sand and clay were sourced locally and from the site.

The clay got sifted through 1/4 inch hardware cloth to get out chunky bits that can lead to weaknesses in the bricks.

To make both the bricks and the mortar, water is mixed with a half a coffee cup of asphalt. The asphalt helps the bricks and mortar resist water. Traditionally, prickly pear cactus soaked in water and fermented was used before the modern convenience of asphalt.

Our instructors went with a mixture of about one part clay to two parts sand for the bricks and mortar. 

A couple of handfuls of straw were added to each wheelbarrow full of mortar and brick mix to add strength.

Here’s the consistency of the mortar.

To make a brick you press the clay/sand/straw/water/asphalt mix into a form made out of 2 x 4 lumber. The nice thing about adobe bricks is that you can custom size them for your project, though there are traditional sizes.

Before you build anything, however, you have to test your bricks. Here you can see different sand/clay mixtures drying in the sun. You can also make a brick out of whatever soil you have on hand and see how it holds up.

The first test Kurt did was drop one on a corner from about waist high. It didn’t break and thus passed the test.

Another test is standing on a brick. Even though the brick we used weren’t really finished drying, they still passed. For a building that will be inspected you will probably have to send bricks to an engineer for more precise tests.

This is the way you stack bricks for drying. Depending on the climate, it may take several weeks before they are ready to use.

And you have to be careful how you transport them. This is the right way to stack bricks when moving them in a truck. If you stack them flat you risk a lot of broken adobe. 

Adobe bricks are heavy. To move them out of the truck we formed a big bucket brigade. Here Kurt demonstrates an advanced technique where you toss a brick to the adobe worker next to you.

Ben explained different types of foundations and how adobe construction can meet even California’s stringent building code. And, yes, if you build it right (vertical rebar and a bunch of other details) an adobe building will stand up well in an earthquake.

To begin our garden wall we placed a “story pole” on each end of the wall to keep everything plumb and on the level.

Since it was just a garden wall and not a building, we did a simple gravel foundation beginning with this trench.

And some gravel-compacting line dancing.

Kurt dry-laid the bricks to emphasize that you should size structures to the dimensions of your bricks to avoid, as much as possible, cutting bricks.

When laying bricks we used our thumbs as a guide to space the mortar joints.

Kurt showed a couple of different ways of cutting adobe. One way was just scoring with a machete.

A light tap and the brick broke neatly in two. This brick is still a little moist in the center–good enough for a garden wall, but not dry enough for a building.

Next, Kurt showed how to shovel the mortar (again, made out of the exact same sand/clay/water/straw/asphalt mixture as the bricks and in the same proportions).

After you dump the mortar, you roughen it a bit with the end of a shovel to make it easier to press the brick into the mortar bed.

Here Kurt presses a brick into the mortar and lines it up with the line attached to the story poles

He also checks with a torpedo level. Kurt explained that you can’t “develop a close personal relationship with each brick.” That is, you have to keep the wall level as a whole unit and not get caught up in overusing the level on each brick. He also explained the work flow. The master mason sets the level of the end bricks and the apprentices fill in the center of the wall. When everyone knows their task, with the master providing guidance, things move along smoothly.

This spoon-like object is what you use for “pointing” or creating the groove in the mortar between adobe bricks.

You can also use a bent piece of plastic electrical tubing as a pointing tool. You only point if the wall will not be plastered. If you plaster, irregularities in the joints help the first layer of plaster adhere.

With a lot of people working, the wall went up fast.

Kurt demonstrates an alternate way of keeping the wall plumb and level.

He also showed how you would integrate doors and windows into and adobe structure.

Nearing completion, the wall is looking so good that I want to rush home and build one myself.

Kurt brought along an assortment of tools that you would use for plastering, including some really nice Japanese trowels. He also explained, that for the first plaster coat, you can also just use your hands. Such is the sculptural quality and plasticity of adobe. You never stucco adobe. Adobe is plastered with adobe and/or lime/adobe mixtures. Typically, plastering is done in three coats, a rough coat, a leveling coat and a finish coat. Screen your materials with progressively finer screens as you go. The materials for the finish coat should be quite fine, say fine enough to pass through 1/8″ screen.

We ran out of bricks and did not complete the wall. It also began to wobble a bit, a sign that it’s time to stop. Four or five courses for a structure is good for a day. Let it dry and it will be ready to continue the next day.

At the end of the workshop we went into a little “homesteader’s” cabin on the property. The deal with homesteader cabins is that back in the 1950s that the government would give you a five acre parcel if you built a shack with the minimum dimensions of 12 by 16 feet. So people built tiny shacks to just those dimensions!

Kurt teared off some nasty wood paneling in the shack to show how you could retrofit a building with adobe. Here he is starting to fill the space between the interior studs with adobe. The idea is that the adobe will insulate the walls, providing vital insulation in a harsh desert climate. This may not work as well in more humid places. Here the thick layer of mud will dry fairly quickly. Elsewhere it might encourage mold.

Next we nailed some reed fencing material over the adobe-filled studs and started to plaster the wall with the same adobe we used to fill the wall. The reed fencing gives the adobe something to hold on to. Here again, as with the garden wall, the interior wall would be given three progressively smoother coats.

The miracle of all of this is that it is dirt. The insulation is dirt, the bricks are dirt, the mortar is dirt and the plaster coats are dirt. Nothing could be simpler. There’s an art to it, to be sure, but its amazingly elegant in its essence.

As the sun set over the high desert landscape we concluded our building and headed over to Pappy and Harriet’s for some beer and BBQ. I’m really looking forward to working with adobe again someday soon.

Scott’s Pepsi-G Stove

If you’ve ever backpacked any distance you’ll appreciate the need to reduce weight, taken to its logical extreme by the sort of folks who cut their toothbrushes in half. This ultra-light subculture, to our benefit, seems to be populated by engineering types who like to create useful lists and detailed instructions. And, even if you don’t backpack, these innovative ideas can be used in your emergency preparedness plans.

One of my favorite ultra-light backpacking gadgets is the Pepsi can stove, which has reappeared on the interwebs, after a prolonged absence, here.

To make a Pepsi stove you take the bottom of a 12 oz Pepsi can and the bottom of a Guinness Draught can and, after a series of precise cuts and pin pricks you end up with a nifty cooking stove that uses denatured alcohol or methanol (both easily obtained at any hardware store) as fuel.

Efficiency-wise, if you consider the ratio of weight to heat output, you’re better off with a commercial backpacking stove and fuel canisters. But such stoves are expensive and the fuel canisters are only available at camping and sporting goods stores. The nice thing about the Pepsi can stove is that it’s almost free to make and you can find the fuel at any hardware store. I keep both a Pepsi can stove and a MSR backpacking stove in my backpack. That way I’ve got a backup in case one fails to work.

Mrs. Homegrown here:

I thought I’d toss in a little more detail for those of you unfamiliar with the concept. A Pepsi can stove is tiny and very light weight, good for two things–ultralight backpacking and as a simple cooking device for what some people call a bug out bag–emergency gear that is ready to grab and go.

I’ve taken one with me backpacking, as my only stove. It works fine, but it is limited in its capabilities. It can boil a cup or so of water at a time, enough to make one person a hot drink, or enough water to rehydrate a pouch of something. You certainly can’t make pancakes over one, and if you have a family to serve, you might want to consider carrying more than one of these stoves.

My camping set up included the stove, a sawed off Foster’s can (you know, those extra large beer cans) as a cooking pot, a circle of chicken wire to balance the Foster’s can upon over the stove, and a bit of foil to block wind. It all tucked inside the Foster’s can for transport and weighted hardly anything. Oh, and I kept the fuel in one of those plastic collapsible water bottles.

As Erik says, a lightweight camping stove and proper fuel canister is a much more flexible and powerful option, but little Pepsi can stoves can’t be beat for price or weight.

Here’s our 2006 post on the same subject–along with a nice photo of ours burning.

Iron Sulfate as a Concrete Stain

My concrete Platonic solids stained with iron sulfate.

I’m not a big fan of concrete in the garden. It raises soil alkalinity (a problem for us, here in the Southwestern US) and it prevents rain from infiltrating into the ground. That being said, concrete is occasionally useful and/or unavoidable.

But I also don’t like the color of bare concrete, nor can I afford the high price of concrete stains. Thankfully there’s a cheap way to stain concrete with iron sulfate, a mineral supplement you can get at nurseries in the Western US (it can be harder to find elsewhere, but Amazon caries it).

Iron Sulfate gives concrete a pleasing, rust colored stain. I recently ended up with a bunch of patio pavers that I stained with iron sulfate in a concrete mixing tray using about a quarter cup per gallon of water. You can also mop it on. Varying the strength of the iron sulfate/water solution you use will increase or decrease the intensity of the stain. Remember that there’s no going back, though. Once stained you can’t get it out.

For more info about iron sulfate as a concrete stain see How I Stained my Concrete Floor.

The Construction of Secret Hiding Places

I love alternate views of our normal notions of domesticity and home economics. On a recent trip to the book section of a large surplus store I noticed our first book The Urban Homestead right alongside books on burying weapons caches, wiring solar panels, acting as your own dentist and assembling SKS rifles. We certainly have exciting company on this journey.

One book in particular caught my eye, The Construction of Secret Hiding Places by Charles Robinson. You can download a pdf of this book for free here. Of course the fact that this info exists in book and interweb form means that the secrets aren’t, well, secrets anymore. Nevertheless, I’ll never view a stairwell, baseboard or that useless space under the dishwasher in quite the same way again.

Do you have a favorite secret hiding place? Anonymous comments are welcome . . .

Homemade cat scratcher

I feel like I should apologize to non-cat people for all the cat-related content we’ve been generating of late. This should be the last cat post for a while. (At least until the widdle snugum wuggums does something adorable!)

We picked up this cat scratcher idea from Modern Cat. That version is much more polished than ours, in fact, it’s downright cute. Ours is also too small–we need to add to it a bit. But you can see how it’s made: strips of cardboard coiled up like a a cinnamon roll, duct tape at the breaks. If you go to the original, you’ll see how they finish the edges.

Easy. Kitty likes it.

Are Pallets Safe to Reuse?

Now you know. Pallet parts have names.

As a fan and proponent of reusing pallets in building projects, such as chicken coops and compost containers, I’m often asked if I think they are safe to use given that shippers and manufacturers fumigate them with pesticides.

In the United States quarantine regulations require that pallets be treated with methyl bromide, a pesticide being phased out due to its adverse effects on the ozone layer. According to Mary Howland Technical Service Manager at Great Lakes Chemical Corporation, a supplier of methyl bromide,

Methyl bromide products are restricted use pesticides. A certified applicator license is required to purchase and use these products and strict adherence to label directions/requirements is mandatory. Under normal fumigation conditions methyl bromide is a gas and when the pallets are properly aerated according to label instructions, virtually no methyl bromide residue remains on the pallets and wood materials.

Now I’m not a methyl bromide fan and I find it’s use as a soil fumigant in agricultural applications appalling.  But I’m not too worried about reusing pallets. That being said, a Tylenol recall was linked to the use of tribromophenol (TBP) to fumigate pallets. Though, depending on if you believe the trade organizations behind wood pallets or plastic pallets (they hate each other), the Tylenol recall may have had nothing to do with TBP which is not used to fumigate pallets in the US.

So, as with most issues on this blog, no easy answer. But I’m still not concerned about using pallets as a building material.

More Pallet Composters

Thanks readers for sending links to some attractive pallet compost bins. The one above is at http://thriftify.wordpress.com/2009/03/12/easy-to-build-pallet-compost-bin/.

Another nice one at http://www.ecodaddyo.com/node/94, though I like to keep the bottom open and the compost in contact with the ground. Correction: the bottom is open on this composter.

It ain’t made of pallets but it looks like it will work nicely and you sure can’t beat the scenery. From Devon Morgan.

Compost Bin Project From Our New Book

Natural Home and Garden magazine has excerpted a shipping pallet compost bin project from our new book Making It: Radical Home Ec for a Post-Consumer World.

I’ve been using shipping pallets as a compost bin for a few years now and they work great. A compost pile, in my humble opinion, should be a minimum of a cubic yard in order to jump start the heat and microbial life that makes for good compost. Nail together a couple of pallets and you’ve got a cubic yard sized pile. 

I’ve got two bins, side by side, but wish I had three. Mine also look like hell since I put them together in a hurry. I much prefer the bin the folks at Motuv in Kansas City created:

To answer ahead of time a question that always comes up–am I concerned about contaminated pallets? In short, no. A longer explanation will have to wait for another blog post.

Leave a comment on how you store compost. And if you’ve got an aesthetically pleasing bin I’m especially interested. Leave a link to a photo.

Mosaics

Above is a table the Kelly and I made many years ago with glass mosaic tile. We copied a portion of an ancient Roman mosaic depicting sea life. It took about 40 hours of painstaking work.

We still have a box of glass tile sitting in the garage and I’m thinking about breaking up the ugly concrete patio in the back yard and doing some mosaics. Kelly is less than enthused about this for a number of reasons, not least of which is that it will take me away from more pressing matters such as a back door that doesn’t open and a non-functioning computer network.

Nevertheless I was inspired to return to mosaic work after seeing the stunning garden designs of Portland, Oregon based pebble mosaic master Jeffrey Bale.

A pebble mosaic from Jeffrey Bale’s blog

You can view Bale’s work on his blog and read a great how-to article Bale wrote for Fine Gardening Magazine.

Our squid table was made by gluing the tiles directly to the wood and grouting once all the tiles were in place. This would not work for exterior mosaics. Instead, for my patio I would glue the tiles to a piece of paper and then set them into a mortar mix in place (the indirect method).

Using pebbles as opposed to glass mosaic tile, by the way, cuts costs way down. Should I get permission to do the back patio I’m thinking of combining pebbles with small areas of glass tile. In fact, I may just stop answering emails so that I’ll have the time to do this!