Original Layout; mostly same content
The date above was the inception date- check the pages for updates! (most recently updated December 2014)
Why I’m constructing alternative buildings: see this page (at right) for a discussion about how building codes enforce and prescribe the construction of burnable, mold prone homes which if insulated with rigid foam, can render you incapacitated within 30 seconds during a fire- or do the same to fire fighters, and cause very intense heat three times that of burning wood. I’m trying to build sustainable architecture- see this post for an overview of what I’m doing and why.
Water catchments & cisterns: this page is a tribute to the fact that even in climates more arid than my own (Such as Phoenix, AZ) there’s enough rain falling on every roof to supply all the water needs for the families that live there. My roofs can collect over 16,000 gallons of rain water per year. (now 22,000 with the addition of a 1,000 square foot attached greenhouse- 2013).
Earth bag structure with intersecting vaulted roof system. From the outside, the earthbag walls rise between six and seven feet, the rest of the wall height is wire formwork and rebar covered in burlapcrete (description follows later in post.) The earthbags are covered in stucco wire and a render made on-site using a tow mixer, composed of adobe from the site, recycled paper, lime, and a little borax. We poured test slabs of this render and built a wood burning stove from it, and it didn’t char or crack after two hours of burning scrap wood with glowing red embers. The outside of the stove wasn’t even hot to the touch, and was three inches thick. One of my favorite observations about paper-adobe when made quite dense and heavy, is that it takes nails and screws quite well, even construction brackets and tico nails, as well as lag bolts and holds them as solidly as wood. And unlike cinderblock, a paper adobe block can survive a direct blow with a sledge hammer with only a dent, instead of shattering. Ten years ago I made over a thousand blocks of dense paper adobe using a tow mixer and drag form, but realized there must be an easier way to build- and became enamored of dry stacking uniform block and surface bonding it (which is vastly stronger than traditional mortar joints by engineering specs), so I built a rammed earth block press using a shop press and 20 ton pneumatic-over-hydraulic jack and a heavy steel form. The press itself flexed under the pressure, and my father suggested if something went wrong it could be quite dangerous, so he pointed out the option of using sand bags to me and the work of Nadir Kahlili who’s books and work subsequently fascinated me. However, when I was first looking into earthbag construction years ago, it just didn’t make sense to me to use tamped earth overhead in my climate. Ultimately, a render or plaster coating needs to be re-coated or fixed, and walking or standing on a somewhat brittle shell on top of a softer substrate, seems like a recipe for cracking and then water infiltration during monsoons and winter storms. In very dry climates, I think its a great idea- but here by the time anyone would know there was a problem, because of the arched dome shape of the roof system, the water would flow down toward the base of the walls and wouldn’t soak through the inside plaster and be visible until there was a lot of water weight in soggy bags of earth, overhead. And soggy earthbags come apart pretty easy. Something like a pond liner would seem like a good fix to use on the roof, but a vapor-proof barrier on the outside only works if you’re not using soluable materials for construction- moisture moves with warm air inside a home toward the outside, and as it passes through walls or ceilings, it cools down and at some location it reaches the temperature known as dew point, and condenses from water vapor into into the liquid stuff. In an earthen building with a breathable roof and wall, the water vapor can either pass all the way through before reaching dew point, or the dampness can escape afterward. If there’s a waterproof barrier, it can never escape, and instead erodes the walls or ceiling and by trapping moisture can give rise to mold. There were some historic adobe buildings in New Mexico that were coated with cement based, non breathing stucco and it fairly quickly started to ruin them. In theory, an earthen dome can survive indefinitely if the exterior stucco coating is kept up religiously, but I’ve noticed that Murphy’s law is pretty prevalent here in the desert- and I figured for myself, sooner or later even if it was thirty years from now, some cracks would go un remedied or too much water would soak through the breathable roof into the earthbags over an especially wet monsoon season, and then I’d be wearing a few tons of wet earth and shattered stucco and stucco wire. Also, that type of construction tends to be limited to twelve or so feet in diamater- I wanted something on a scale that would seem ‘plausible’ to the average American consumer so I built a 40′ diameter round house with mostly open interior space, and a 20′ x 50′ shop structure.
(above) roof covered in expanded metal lath. (below) thin shell of grout embedding metal lath.
(Above) Shop roof with glass block cuppolas topped with swirled roof caps and lightning rods.
(Below) Round House with burlap-crete walls. A round house with round rooms- the rooms are used 10,000 gallon water storage tanks. A heavy guage wire form is built, over which sheets of burlap are draped, which have been soaked in a modified rapid setting cement (details in other postings on this site.) I wanted a wall system that was quicker and less labor intensive than earth bag construction, yet non-flammable, and not prone to molding so I experimented with and developed this method of construction which requires much less labor and materials than ferrocement, and allows one to build a sculptural formwork over which the skin of the house is draped and clamped in place with clothes pins while the rapid setting cement hardens to 3000 pounds per square inch compressive strength in about half an hour. Without modification, the result was too brittle however, so I added acrylic polymer to the rapid setting cement to give it some elasticity. The resultant burlap-crete will flex and recoil from a hammer blow, whereas before it was more like swinging a hammer at a sheet of very thin drywall gypsum board.
(above) view looking south. (below) view looking north.
The roof is not burlapcrete but closer to being ferrocement: steel framing covered in galvanized stock panels which are covered in galvanized expanded metal lath, attached with a hog ring gun (thank you, Paul Sarnstrom of ferrocement.net). After trial and error experimentation, instead of multiple layers of expanded metal lath as in traditional ferrocement work, I used only one layer of lath and instead of cement, I used construction grout modified with chopped PVA fiber (poly vinyl acetate) because it bonds much better than fiberglass or other cement reinforcement, and adds a lot of tensile strength and some flexibility. For added elasticity and flow control, I added acrylic polymer as well. The main reason for the use of the grout, was that it was non-corrosive to steel reinforcement, plus it was a ‘non-shrink’ formula which I figured would be a boon in the prevention of cracking. The grout shell of the roof is only 3/4″ to 1″ thick. In the finished product, a number of hairline cracks did appear during and after the curing process, which I addressed with an acrylic based concrete crack filler. The grout is pourous so the roofs require a waterproof coating. Traditional metal reinforced concrete and ferrocement work have a theoretical design life of approximately fifty years due to cement’s absorption of water and chemical make up, both of which function to corrode the steel.
My goal is to build structures that are not likely to burn or rot- which automatically rules out wood frame constuction or plywood sheathing, as well as ruling out most foam insulation for its flammability issues, drywall because it holds moisture and promotes mildew as a result, and all aspects of strawbale construction are also unsound in my opinion. I know most folks swear that strawbale doesn’t burn, but it definitely rots and the mold can make the structure unlivable as it has in an unoccupied strawbale house ten miles from my building site. As for fire concerns, my neighbor’s strawbale home burned to the ground. The general argument is that strawbales are packed so densely its nearly impossible to get them burning in a meaningful sense, but my feeling is that you’re not going to get it so dense as a block of wood no matter how hard you try, and wood burns quite well (though heavy beams do tend to burn just a little and then are oft protected by a layer of charred material). However, its been my observation that even thick logs in the fireplace burn just fine if given enough time. (No fire district where I live, no fire department to respond to a house fire.) Murphy’s law is always in effect- hope for the best but plan for the worst. Even brick buildings are destroyed by fire if the roof is wood framed and that framing is sheathed in plywood- the burning mass of the roof system collapses in on the brick walls, often bringing them down- whether it does or not, the contents of your home are destroyed. In case of flood, wood frame with sheetrock is a disaster- the mold and mildew of New Orleans being a case-in-point; the same rot problems associated with standing water can happen with strawbale.
Above- view from roof of sand-bag shop structure, looking toward round house near sunset.
South-facing clerestory window (in shadow), made from glass block. A north-facing clerestory is on opposite side. Roofs of both buildings to be treated with multiple coats of natural limewash for waterproofing. The round house has a vented attic/plenum chamber which draws air in from under the eaves and exhales through three vents in the glass block cuppola (one vent visible in these photos). I had thought of using an elastomeric paint on the roof, but would have needed to use a water vapor barrier paint on the underside of the roof to prevent the elastomeric paint from ultimately losing its bond with the roof surface, due to water vapor passing through it and lifting it off over time. Limewash is waterproof but breathable, and also any cracks that develop in lime coatings, have a distinct tendency to self heal. Also, years down the road when they need recoating, one simply washes the surface and applies a fresh coat– no stripping or other preparation is necessary, and limewash is an ideal coating for absorbant masonry surfaces. Lime has many other beneficial attributes, discussed elsewhere on this site.
Twelve sided glass block cuppola rising from center of house, cuppola diameter is eight feet and sits directly over the bathroom. With the cuppola, the bathroom is eighteen feet from floor to ceiling, rising through the attic/plenum and allowing natural light into the bathroom which being at the house’s center, has no other windows. After these photos were taken, lightning rods were fitted to the high points of the roofs. (SE Arizona is second only to parts of Florida in terms of the intensity of electrical storms.) The rods were grounded using half inch diameter stranded copper cable.
In the shot above with the fantastic orange cloud, you can see I’ve done some remodeling (summer 2013). On the shop building I’ve replaced two windows with one eight foot wide picture window (facing nearest mountains), and on the right of that structure you can see the frame of the 1,000 square foot attached greenhouse.