Solar Adobe School - Learn about Adobe Construction, Adobe Home Building, Adobe Bricks, Green Building, Rammed Earth, Pressed Block Construction, Earthen Construction, Adobe Drafting.

SWSA Classes for Spring 2012 ~

SWSA offers "a class for just about everyone" this spring. Whether you're planning a starter home or a super-hacienda, our practical classes will teach you how Adobe, Compressed Earth Block and Rammed Earth homes are built to code- with an eye to using the sun and keeping coins in the pocketbook. Note that you can attend a planning class earlier in the spring and then follow-up with a Hands-on one later, when warm days are here.

Looking for masonry skills that elevate you above the norm? Consider our class on Arch/Vault/Dome construction, which includes adobe Hornos. These popular, round-shaped, earthen ovens are primarily for baking bread, but also for cooking meat. Building the historic, adobe horno is a smaller project with big rewards. A dozen chocolate-chip cookies bake in eight minutes and a 160-pound pig in about nine hours, depending on horno size and type of wood. Be sure to scroll down and check the Arch/vault/dome/horno class.

As the recession drones on, glimmers of new energy in the Southwestern economy encourage us to stick with our main teaching points: controlling and reducing building costs, utilizing solar design and incorporating practical, regional styles. Those factors, along with Adobe's inherent green qualities, continue to make the 'custom adobe' (and other earthen cousins) most-favored for appreciation in the Southwestern residential market.

Cash Rebates are in place if you sign up for more than one class during this spring period. Starting in 2012, if you aren't interested in a money rebate, you can take the equivalent in Adobe Builder back issues.

SWSA classes will help you plot a stepped-progression to a successful completion of your Adobe or Earthen home. It's too important to not plan it right. And while your initial design work will cost you time, it requires only paper, pencil and ruler to begin your floor plan ideas. Why not start today?

Details for the five spring classes are listed below. Costs are the same as last year, with the exception of the Rammed Earth Hands-on class (which spans 2 ½ days) and the Vault/dome class, which requires extra set-up for SWSA.

1. Building the Low-Cost Rammed Earth Home
Early Bird Planning class
March 31-April 1 (Sat-Sun), 2012
North Albuquerque, NM, Courtyard by Marriott (505) 823-1919
5151 Journal Center Blvd. At I-25

Please scroll down to Class #4 for an overview of Rammed Earth.

Schedule ~
Saturday, March 31

8:00am - 9:00am - Rammed Earth Review ~
Explains what Rammed Earth is and why it's a proven technique. A survey of Equipment and tools is important: Forming System choices, Straps, Ties, and Job-built fillers are reviewed. Tamper, Tractor/loader and Air Compressor choices. A look at Mixers, Conveyor Systems and the essential sundry tools.

9:00am - 10:00am - Site Prep ~
How to pick a better building site for Rammed Earth and why when and where you place things can save you bucks, such as your main selected soil pile, setting up for Stabilization and Material Delivery to the forms. How to determine the amount of material you will need. What the code will require around your building site.

(Ten-minute break and ordering of lunch tour burritos)

10:10am - 11:30am ~ Foundation Systems.
Rammed Earth typically requires wider foundations, but there are ways to cut concrete costs. A study of both conventional and alternative systems and their code requirements, including perimeter insulations. A look at a foundation system for double-rammed earth walls with insulation in-between.

11:30am - 2:00pm ~ Touring munch-lunch.
Class visits viga/latilla yard and tours a commercial rammed earth facility (plant nursery). Valuable for the look, feel and cost of the materials- bring your camera and notepad. Free drinks and burritos provided by SWSA. It's a continuation of the classroom, so we ask you not to depart to another lunch location (you'll miss out !).

2:00pm - 3:30pm ~ How to identify suitable earthen material for your Rammed Earth project. What are the code minimums? Rammed Earth mixes are somewhat different from those for Adobe or CEB. But they all must pass testing for compression and modulus of rupture. We'll show you simple field tests that get you in the ballpark.

(ten minute break)

3:40pm - 5:00pm ~ Stabilizing Rammed Earth to meet the code. In some areas (like California), all earthen materials must be stabilized against moisture by code. In others (like New Mexico), you have the option of building with or without a stabilizer. We will review the common stabilizers, their properties and how they are mixed with your chosen earth material. Once your samples are cured, they must pass water resistance tests prescribed in ASTM and the NM Earthen Building Materials Code. You will be required to prove your material via a soils engineering test- we'll show you how to save bucks on soils engineering tests.

5:00pm - 5:30pm ~ Compaction for Rammed Earth requires knowledge about moisture content of the soil, thickness of the lift and how to tamp it. A study of different tamping tools and techniques, using hand tampers and "pogo" backfill tampers that run off air compressors. Safety points and cost differences for different models. How to "leave" a wall under construction with "keys" for the next days work. Code rules on covering a wall in progress.

5:30pm ~ Class over for the day.

Sunday, April 1

8:15am - 9:00am ~ Door and Window Treatments and "Nichos".
How to prepare openings for Rammed Earth. How job-built fillers and "displacement boxes" are set and braced to define openings, including larger areas for passive solar gain on the south. How to prepare openings for the architectural style you are planning. How to save wood on extra-wide lintels in R.E. walls.

9:00am - 10:00am ~ Efficiency and Safety in form setup and removal.
Typical rammed earth forms are not light in weight, but can be handled by a single person who knows the rules. Loading and unloading them is better done with help. Setting them up isn't difficult, but safety must always be observed. Detaching them from the wall without hurting the wall surface can be tricky if you don't know the procedure. We'll go over the main points (and tools).

(ten minute break)

10:10am - 11:15am ~ Bond beams.
The bond beam "locks" the walls at their tops and provides strength to the structure. This code-required element of your project can be done in wood or concrete in New Mexico, but must be all concrete in California and a few other areas. Setting up for a concrete bond beam is easier, quicker and cheaper for Rammed Earth than for Adobe and CEB. We'll show you why.

11:15am - 12:30pm ~ Traditional Roof Construction.
Once your bond beam is done, you can attach any roof system to it that you like. Rammed Earth advocates like traditional roof styles as much as Adobe builders do, so we'll show you how a roof in 1712 was built and how that same style can go on your Rammed Earth structure. What about parapet-style roofs? We'll explain the options. Learn about materials, artistry and how much you can do yourself to cut costs.

12:30pm - 1:45pm Lunch Break (on your own)

1:45pm - 2:45pm ~ Contemporary and Passive Solar Roof Construction
Shed, Gable and Hip roofs are all possible on earthen structures. Combination roofs that use many of the old traditions, such as vigas, along with newer, pitched designs are commonly done. Whichever you like, your roof will have to meet the energy code as well as the structural code. Start to get a fix on wood choices, logistics, costs, tools and the many artistic finishes possible. Learn why simple truss designs may be greener as well as cheaper for some projects and why hip roofs are better in seismic zones.

(ten minute break)

2:55pm - 3:55pm ~ Passive Solar Summary.
We will have been integrating passive solar techniques into each of the above categories during both days. During this 60-minute summary, we'll review how a good thermal wall system works and your wall/roof thermal choices, such as insulation on a single wall, insulation between two walls and green, hybrid systems, using Light Clay, cellulose and others.

3:55pm - 5:15pm ~ Plasters and Stuccos.
Codes give you a lot of leeway on your interior wall finishes, but are stricter on the exteriors. What about artistic interior finishes for Rammed Earth left exposed? How much can you do yourself with a few friends? When should you call in the pros? What about lime stuccos? Which finishes can take a hailstorm? Thermal is important for both low-desert and high-plateau dwellers.

5:15pm Certificates of completion.
Class ends.

Cost: $255 one person, $433 for two registering together (web site adds state tax to these figures).
Class capacity: 16 students
Class Handouts: Rammed Earth Plan 1680, Earthbuilders' Encyclopedia CD and various hard copy handouts, plus issue 9 of Adobe Builder, dedicated to R.E.

2. Building the Low-Cost Passive Solar adobe or CEB* Home
Early Bird Planning class
April 21/22 (Sat-Sun), 2012
North Albuquerque, NM, Courtyard by Marriott (505) 823-1919
5151 Journal Center Blvd. At I-25

* CEB = compressed earth block

The objective for this largely indoor class is building the basic Adobe or CEB home that completes kitchen, bath, bedroom, living room, storage and PV area, with options for later expansion. You will be provided details about code, drafting, passive solar design, PV components layout, tools required and cost options, along with a set of working drawings for one of two Solaradobe choices (Plan 1576 or 1310).
Both of these Plans have been built to code in New Mexico.

Schedule ~
Saturday, April 21, 2012

8:00am - 9:15am - CUTTING COSTS in ADOBE OR CEB CONSTRUCTION.
The obvious one is not to build too big, but there are several other areas in the home layout, the foundation, the walls and roof where the choice of materials- and how you draft them can lower your costs. We will list and review them. If the home will be expanded in the future, how will you depict that on your plans? What can you build or buy before construction that will save you time and money? Should you decide to sell your home at a future time, what will make it attractive to tomorrow's buyers?

9:15am - 9:25am ten-minute break and ordering of lunch burritos.

9:25am - 11:30am - THE CODE AND YOUR PLAN - being knowledgeable about the Earthbuilding Code and how it relates to your plan can save you bucks. Our way of teaching is to explain the code, while pointing out money savers that meet code. Students receive a code copy. We review the main points you must know. We will look at each plan sheet, reviewing the important code points and how you can save without reducing the strength and performance of the home. For example, a plan for a passive solar home must follow standard drafting practices, but building a south solar array is similar to timber framing large south glazed areas to pull in the winter BTU's. How will they be depicted on your plan? (two standard ways to draft for south units - the less expensive and the more costly). Another example- how to design and draft to save on concrete foundation costs. A recent student who used this proven technique saved over $800 on concrete costs for his 1800 sq. ft. Adobe. Yet another example- what is cheaper, a fully stabilized, exposed earth wall, or a plastered, unstabilized wall? And if you plaster or stucco certain areas, which type of cover or finish can save you money? (Hint: showing off your coursing can be the way to go, but you still need to know a few tricks).

11:30am - 2:00pm ~ Touring munch-lunch.
Class visits viga/latilla yard and adobe yard. Valuable for the look, feel and cost of the materials- bring your camera and notepad. Free burritos ordered earlier are provided by SWSA, so we eat as we tour. It's a continuation of class, so you'll miss out if you dine elsewhere.

2:00pm - 3:00pm - THE CODE AND YOUR PLAN CONTINUES
We'll work our way up through walls and bond beam and into roofing considerations. What is a green, but fairly priced insulation for the roof cavity? What are two owner-builder friendly roof constructions? What is the cheapest metal roofing design (while still using a quality 26 gauge material)?

3:00pm - 4:00pm - SLIDE SHOW with Q&A period- examples of what we've been discussing. Clearing up confusions about the choices. Short break during show.

4:00pm - 5:00pm - TOOLS AND MATERIALS YOU WILL NEED you already own some of the tools you'll need- like a skill saw, hammers, shovels and wheelbarrow. You'll need a trusty pickup truck. But some tools and materials are unique to Earthbuilding. Save money by acquiring or making some of them well before your project begins. If you don't know about them until their need is apparent on-site, you lose time and can disrupt the workflow. An example is adjustable speed leads. You can't buy this style off the shelf, or from any masonry supply. We'll bring one into the classroom and you can see how they're built. (Hint- if you know how to use a torch, great. If you don't, find a reasonably priced welder beforehand.)

Sunday April 22, 2012

8:15am - 11:30am - PASSIVE SOLAR and PV DESIGN -
We need to know how to save money building the home, but we also want it to save us money, ENERGY WISE once it's built- in fact, we'd like the home to be a surplus energy-producer, rather than an energy-consumer we have to pay for. That's where Brother Sun comes in. Passive Solar is popular as a wintertime heating technique, but it also works well for summer time cooling. You should start with Passive Solar as your basis, then add other green technologies, such as Solar Electric (PV), to cover more energy needs. Short break during mid-point of this session. We'll review the do-nots and the do's, along with guide lines about window types for Solar, Ratio of south glass to heated floor area for different SW climate zones, Design of Solar overhangs, Shading, Interior wall mass and a number of other, less costly applications. Example: Save money in some rooms by installing a poured adobe floor. Pick a red-brown soil, finish it dark in color and it will serve as a comfortable solar absorber for those low winter sun BTU's. (But you won't be able to wear spike heels or cleats in those rooms!).

11:30am- 12:45pm - Lunch Break (on your own today)

12:45pm - 3:45pm - QUALITY ADOBE OR COMPRESSED EARTH BLOCK
Should you make your own blocks in the first place? Making adobes or earth block is an entirely different world than building the house. If you do your own, you'll need to make them separately and well before the building begins, unless you are using a pressing machine and have a qualified soil already prepared. Short break during mid-point of this session. Today, costs have driven up the price of everything- including the adobes or earth blocks themselves. Yes, you can save bucks by making your own locally or on your site, but even if you plan to buy them, you should know how to recognize a quality block or adobe and what the code says about compression and modulus of rupture. How would you find a qualified soil that meets the code? What if you want to stabilize your blocks- what are the options and costs? LCD slides and show-and-tell with different specimens.

3:45pm - 5:00pm - FINISH WORK – and MINIMIZING IT TO SAVE MONEY
The finish work stage is where many owner-builders spend much more time than they expected and where many contractors lose their profit margins. This is also where the value of a good set of plans becomes apparent (as the devil is in the drawn details). Consider off-the-shelf sizes and materials and how "smooth", "rustic" or "textured" you want different surfaces to be. Think details out room-by-room and how to develop a team approach to finish work. We'll cover the main options.

5:00pm - Certificates of Completion handed out, class ends.

Cost: $255 one person, $433 for two registering together (web site adds state tax to these figures).
Class capacity: 16 students
Class Handouts: Earthbuilders' Encyclopedia CD, hard copy handouts and Plan Set 1310 or 1576 (your choice: visit www.adobebuilder.com for plan descriptions)

3. ADOBE & COMPRESSED EARTH BLOCK
Hands-on Class
May 5/6 (Sat-Sun), 2012
-at the SWSA field station, Bosque, New Mexico (38 miles south of Albuquerque)

This class devotes the weekend to preparing Adobe and CEB earthen materials, using tools of the trade and working on real walls. The idea is to teach you important basics and give you a sense of heft for the tools and materials. Please note that Saturday's class will go to 5:30 pm and Sunday's class to 5 pm*.

The nearest town with a plentiful choice of motels and restaurants is Belén, located 8 miles north on state highway 116. Belén is 32 miles south of Albuquerque on Interstate 25. Local directions, map and list of accommodations when you register. Weather in late May is warm with pleasant evenings. This is a rustic class in the rural countryside. Dust, wind, and insects may exist. Old or work clothes are best, along with hat, gloves, sunscreen, polarized sunglasses and good foot protection.

You may 'brownbag' your lunch at the hands-on site or drive into Belén for lunch. Coffee, water and cold fruit juice are free on-site each day. SWSA will provide tools and materials. If you drive to class, you may wish to bring some of your soil for testing (two 5 gallon buckets are ideal). Bring your notebook and camera. Safety will be stressed: SWSA will ask you to sign a release before class.

*travel time from the Bosque country site to the Albuquerque airport is about 50 minutes via I-25. From Bosque to Belén is about 10 minutes.

Schedule ~
Saturday, May 5 (Cinco de Mayo)

8:00am - 9:30am - Tools and Safety
Earthbuilders' Encyclopedia CD distributed along with handouts. Safety is discussed as we review both common and unusual tools used with Adobe and Pressed Block. Show-and-tell tour of features around the site such as adobe dome, Count Rumford fireplace, different wall finishes and different soils. Rather than call specific breaks, students can short-break as needed during hands-on periods. Coffee/water/cold drinks free on site.

9:30am -12:00 noon - First Hands-on period.
Instructors will direct students in setting up leads, preparing mud mortar, and laying adobes and compressed earth block to the string. Learn aspects of wall construction as we go along- speed leads, placing adobes, code overlaps, cutting and shaping of blocks, finishing joints, rough bucks and their attachments, electrical circuits, box attachment, in-wall reinforcement and more. We'll be building the base for the horno class, to be held later.

12:00 noon - 1:15pm - Lunch break.
Brown bag on site or drive to Belén (8 miles). Cold drinks and water free on site.

1:15pm - 5:30pm -Second Hands-on period.
Continue wall construction from morning period. At mid-afternoon, change to making 3 different types of adobes using forms on site. Learn how stabilizers are proportioned and mixed. Clean up tools and wheelbarrows starting at 5:15 p.m. Class ends at 5:30

Sunday, May 6

8:15 am - 12:30 pm - Third Hands-on Period.
The morning is dedicated to Compressed Earth Block. Larry Elkins of Adobe International will visit and demonstrate one of his compressed earth block machines (those who brought soil can use it for testing purposes and we will press it on site). Larry, Joe and students press different blocks with Cinva-Ram and Adobe International Hydraulic Presses.

12:30pm – 1:45pm Lunch Break
Brown bag on site or drive to Belén.

1:45pm - 5:00pm - Bond Beam Construction- fourth Hands-on period.
We'll get up on the scaffolds, to study bond beam construction and see vigas strapped in place. The use of 1" x 8", tie wire, spreaders and form clips, steel layout, holey adobes, FHA straps for viga attachment and other standard bond beam components will be taught. For those leery of heights (your feet will be about 6 feet off the ground), we have an actual-size, bond beam dummy set up on the ground for you to photograph.

Clean-up of tools and loading of students' test blocks starts at 4:45 p.m. Note: if truly bad weather occurs on either day, class may be moved indoors for continued instruction. Class ends at 5:00pm with Certificates of Completion.

Cost: $255 one person, $433 for two registering together (web site adds state tax to these figures).
Class capacity: 18 students
Class Handouts: Earthuilders' Encyclopedia CD, various hard copy handouts and your choice of Plan 1576 or 1310 (both have been built in NM to code).

4. Rammed Earth
Hands-on Class
May 18 (half-day) through May19 and 20 (Fri afternoon-Sat-Sun), 2012
-at the SWSA field station, Bosque, New Mexico (38 miles south of Albuquerque)

Rammed Earth walls start at 18 inches thick and go up to 36 inches thick. They are ideal if you want a super- thick wall. Interested folks tend to be those who are curious for a variety of unique reasons. Examples are stopping radioactivity (24" of earth stops radioactive fallout), seismic design (strong against earthquakes), security (will stop up to small cannon fire), or sculptural reasons (one can do more practical, architectural expression with a super-thick wall). Yet another reason is using rammed earth as a first story base for a second story in Adobe or CEB. Rammed Earth walls however, are lousy for curves or circles. The forming systems make them great for squarish or rectangular designs. They are also more efficient for ramming the two-foot thick base walls under Adobe vaults or domes.

Those on a budget will appreciate that by repeating a certain set-up of forms, it is relatively easy to ram a good-sized room in less time. In ancient Rome and through Beethoven's time in Europe, all ramming was done by hand (still true if you have strong shoulders). Starting with the Industrial Revolution, mechanical advances slowly lead to the machine-powered tools of today. If you are a R.E. business, you are likely to own these tools. If you are an owner-coordinator, you can rent most of them.

The secret to success is a crew that is adept at using the tools, knows how to prepare soil stockpiles, understands stabilization and quality control and can handle form set- up. Key also is steady soil delivery, quality tamping and efficient form takedown. If you can keep finish details simple, you can cut costs. If you'd like to incorporate exposed adobe walls within your structure, the NM code lays it out (we will explain). Knowing Rammed Earth puts a big feather in the cap of any builder, allowing you to say more than, "...er, I can only build you a 6" frame wall.."

The nature of this class is mostly outside under semi-rustic conditions. Bring supportive footwear (no bare toes), hat, gloves, safety or polarized glasses, note-taking materials and your camera. Water, coffee, cold drinks and Portapotty on site. We will ask you to sign a release, due to the increased safety concerns with heavy equipment, noisy air compressors, tractors, pneumatic tampers, etc. We will discuss the Buddy System for safety before starting any machine.

Schedule ~
Friday May 18 (half-day)

1:00pm – 5:00 pm Orientation and Review of Equipment, Tools and Drafting Requirements for Rammed Earth Structures.
We will cover as many of your questions and concerns as possible, before beginning work tomorrow morning. You will be given a set of plans (RE Plan 1680), along with a comprehensive handout for Rammed Earth, including notes from Australia and a reading reference list. We will go over Rammed Earth requirements in the NM Earthen Building Materials Code, the leading code for this wall system in the United States. Learn how to join rammed earth and adobe or CEB walls to code. We will also talk about cost of equipment, both new and used, to include Air Compressors, Tampers, Skip-loaders, Conveyors, Forms and other tools. Safety concerns and what sorts of skills your crew should have will be discussed.

Covered also will be ramming around plumbing and electrical systems to code, ramming walls with insulation in-between, Bond Beams for Rammed Earth and ways to save dollars on wide footings. The approach will be to work on a solid wall the first day and then do a portion of double wall with insulation in-between on Sunday.

Saturday May 19

8:00am - 11:30am We huddle to plan "objectives of the day". SWSA will have the footing already in place, so students will start with forming set up. You will be handling typical plywood and steel forms, using dimension straps, steel wedges, job-built fillers and other apparatus typical on a rammed earth site. Both for safety and learning reasons, we will go slowly, making sure that you understand the steps. We will install a few electrical boxes, with a pipe (conduit) system. Last, will be the job-built fillers for a door opening. These deploy ¾" plywood and bracing. They must be installed before ramming begins.

Take breaks as you need them. Portapotty on site.

11:30am - 12:45pm Lunch Break
Brown bag on site or drive to Belén.

12:45pm- 5:00pm The afternoon will stress Soils and how a stabilizer is added and mixed. An important aspect to Rammed Earth is the proper water content, called "optimum soil moisture". Too wet and the soil will be like ramming Jell-O. Too dry and the soil will "plate" and spall when rammed. Students will mix the soil with the proper amount of Portland cement and we will not mix more than we can ram in the following 60 minutes. When ready, the mix will be shoveled (or dumped using a tractor) into the forms. At this point, students learn about lifts, how deep to place them and how to tamp them. We will proceed with ramming, and students taking turns with the tamper. The objective will be to finish this wall section by days end. We will leave the forming in place until tomorrow morning. Of interest here is that we should be able to bring this wall to bond beam height, leaving a void for a concrete bond beam pour.

5:00pm Clean up tools and equipment, day ends

Sunday May 20

8:00am - 11:30am
The day begins with coffee as we gather by yesterday's work to remove the forming. There are a few "tricks of the trade" to be aware of here and we know you'll be keen on them, since wall appearance may be important should you be exposing some of your walls (without a plaster cover).

We should have reached bond beam height yesterday (8'), so we may remove all but the top tier of forms, leaving those as a void for the bond beam concrete pour. This will give students a chance to see how forms adhere to the wall without support beneath (straps exist), and to see the time advantages of using plumbed and leveled forming for the tops of your masonry, especially when pouring a Bond beam, which determines the level and plumb of your roof carpentry.

We should also remove the Malibus (Australian term) or Job-built Fillers set in yesterday for the door opening. You will see why the argument can be made as to why RE is greener from a wood-use standpoint. However, if tradition dictates that you must use wood (for style, etc.) then it is easy to set up.

Take breaks as you need them.

Once those tasks are accomplished, we will switch to the other project (about 30 feet away), in which we will be inserting an insulation core between two RE walls. The class works on this set up until lunchtime. We will also insert a nicho form, to be extracted later. Nichos are shaped wall cavities, handy for art objects, landline phone stations or tile/planter backdrops. The R.E. code covers nichos very well.

11:30am - 12:45pm Lunch Break
Brown bag on site or drive to Belén.

12:45pm - 4:30pm We will proceed with ramming around the insulation core. Students will take turns with the tamper. We will raise this wall section as far as possible by days end. Thermal research done in AZ and NM in the period 1976-1985 proved that a double earthen wall with an insulation core is the most thermally effective in both super hot and super cold climes. When such a wall is stabilized, then no plaster or stucco (by code) is required on the exterior, greatly reducing costs.

However, doing this is tricky. You will see why when looking at an adjacent wall done 2 years ago. While that wall is acceptable, you will appreciate why care must be taken with ramming pressures. We will try more than one type of 2"insulation board on our project, to see which works best. You can be part of the research towards better solutions- and SWSA students often come up with some great ones!

4:30pm up tools and equipment, class ends with Certificates of Completion.

Cost: $335 one person, $569 for two registering together (web site adds state tax to these figures).
Class capacity: 12 students
Class Handouts: Earthbuilders' Encyclopedia CD, various hard copy handouts including NM Rammed Earth Code and Plan Set 1680 for Rammed Earth (the rammed earth equivalent of Plan 1576). Instructors: At least two instructors will be on site, one from SWSA and one from our pool of licensed Rammed Earth contractor allies.

5. Special class: Intro to Arches/Vaults & Domes and Building the Spanish/Pueblo Horno
Hands-on class ~
June 2 & 3 (Sat-Sun), 2012
-at the SWSA field station, Bosque, New Mexico (38 miles south of Albuquerque)

While one can build an Earthen home without arches, knowing how to build them places a definite feather in the mason's cap and is essential to build the best horno. Masonry Domes and Vaults, while ancient in history, are noted in modern, custom homes, especially over Breezeways, Entrances and for individual rooms, such as a Study or Library. And they use zero wood. However, building one is a serious matter, as you are placing weight directly overhead. You must understand the forces within walls and how earthen materials are stabilized for safety reasons. We will ask you to sign a release, due to the increased safety concerns. A list of references for further study will be provided at class.

Schedule ~
Saturday June 2

8:00am - 8:45am Safety concerns and site review.
We'll start our class at the SWSA Field Station with coffee and handout materials. Check at the bottom of this class on what is included in the handout package. We will ask you to sign a release, due to the increased safety concerns when up on the scaffold and with other constructions in this class. We will look at the tools and workstations and go over safety concerns for them. We will ask you to wear a hard hat (provided) when working on the scaffold under the dome. Your footwear should have good toe protection and support.

Shallow arches should never be attempted, due to their propensity to collapse. We will review dangerous forms and shapes that you should avoid.

8:45am - 11:45am Study & Construction of Arches
Learning about arches is a great way to begin your apprenticeship for domes and vaults. Consider that an ordinary Roman arch becomes a dome when turned 360 degrees. Arches, when well finished, add style and glamour to any room. They also serve to redistribute masonry loads around doorways and windows. And they save money. If the passage from one room to another does not require a closure, then an open archway saves the cost of wood bucks, the door, and the door hardware. Open arches can help air movement in passive solar homes, where open floor plans are encouraged to stabilize interior temperatures. Most window companies offer half-round windows designed to fit in standard arch sizes.

Breaks are as you see fit. Coffee, juice, water on-site. Portapotty on site.

Instructors will start by building a Roman arch as a demonstration. Students will then build one with instructors helping. If the first try fails, not to worry- we will simply rebuild it. We will go over how the arch form is built, how to select blocks for the arch, mud mixes for the arch, friction edges for the arch and dropping the form.

Our next project deals with the Gothic or Egyptian arch. These are the pointed arches seen in churches and cathedrals and their origins go back to ancient times in many Mediterranean cultures. We will show you how to build an Egyptian 3/5 arch, as well as a 3/6 and the use of pencil and string to scribe them. These types of arches can use a keystone, which can be shaped from an adobe block.

Pointed arches are standard in an adobe vault or dome, and they must be two-feet wide or more to carry the weight of walls above, plus the weight of the dome or vault above that. They support door and window openings. Thousands of years ago, Nubian masons evolved safe ways to build them by inter-weaving the adobes two and three generations thick. We'll show you how a double-woven arch is done and how the arch is begun by setting up the form and starting the pattern. Students will practice by building one with instructors' help. Bring your camera.

11:45am – 1:00pm Lunch Break
Brown bag on site or drive to Belén

1:00pm - 5:00pm Building the 'Poor Man's' Dome.
This type of dome turns a square room into a round, hemispheric dome using pendentives. It uses fewer adobes than the more complicated Sassinid Dome, thus the poor man name. Base walls are two-feet thick with pendentive and dome walls at 10 inches thick. We'd like to see you up on the scaffold (taking turns, 2 students at a time), building the dome. We will explain the design and geometric considerations, forces in the structure, use of centering pole, types of mud mix, use of stones as ring wedges, finishing inside and plasters outside. Stress will be on Stabilizing the adobes and mud mortar, using emulsion, Portland cement or Lime. Stabilization is a safety MUST for domes and vaults.

5:15pm - 5:30pm Tool cleanup, day ends. Students are welcome to stay on-site after 5:30 until dusk to practice on non-scaffold arch forms.

Sunday June 3

8:15am- 8:45am Coffee and multiple-choice quiz about stabilization
Be sure that your understanding about stabilization is correct. Take your quiz papers home. Very important! Non-stabilized adobe vaults and domes predating the time of Christ still stand in Egyptian deserts, but those deserts might get 2" of rain a year. North-American deserts receive from four to six times more moisture in a typical year- for example, 11" around Tucson in the Sonoran desert. You will be placing over 100 pounds per cubic foot over your head- Safety first !

8:45am - 12:45pm Building the Spanish/Pueblo Horno.
Originally introduced from Spain to the Américas, New Mexico's Native American Pueblos utilize hornos constantly throughout the year, producing the famous bread loaves and pastries. The adobe horno increases home value, adding a great 'back-porch' gathering place. It is the ultimate low-tech, survival appliance (no propane/gas needed!). We will build our horno on top of a base already constructed during the earlier Adobe/CEB hands-on class. After previous talk about the importance of stabilized materials for big domes and vaults, we switch to the importance of non-stabilized materials when building an oven for foodstuffs. Students will build a round horno, based on yesterday's know-how. We will cover door design, thickness of horno walls, mudding the horno, smoke holes, curing time, wood choices and cooking in the horno.

Take breaks as you see fit. This morning session is longer than yesterdays

12:45pm – 2:00pm Lunch Break
Brown bag on site or drive to Belén.

2:00pm – 4:00pm Building the Catenary Vault.
This type of tall arch is stronger than any other arch and is an ancient form, used throughout the Old World deserts. To build one, you need an espar or 'kick wall', against which the vault is constructed. To visualize one, consider the tiny mud vaults built by mud-dabber wasps and you'll have the idea! Again, with this form, stabilization of the vault materials is very important for human safety.

Well show you how to scribe the Catenary vault and then students will begin the coursing for the vault against the kick wall. In Egypt, masons build them out into space without guides, but it typically takes three years of apprenticeship to acquire that skill. We'll show you methods that do use guides to help you get a start.

We will cover forces exerted by the vault and how to build the base walls that support them. Instructor Joe Tibbets will sketch out these basics on a large newsprint pad, but you'll also have them on your hard-copy handouts.

4:00pm – 5:00pm Recipe for building vaults using adobe quemado and lime-based mortars. In Mexico and the Southwestern USA, vault/dome work is often done using burnt adobe (kiln-fired) and lime/Portland based mortars. This is essentially stabilization by way of vitrification (firing to a ceramic state). We'll show you some of these adobes, called cuñas, and a small vault built with them.

Class ends at 5:00pm with Certificates of Completion.

Cost: $325 one person, $552 for two registering together (web site adds state tax to these figures).
Class capacity: 16 students
Class Handouts: Earthuilders' Encyclopedia CD, Vault/dome engineering report from Cairo (give it to your doubting engineer) and Reading Reference list for Vault and Dome Constructions.
Instructors: At least two instructors will be on site from our pool of bovedero allies (James Anthony, Ernest Aragón, Joe Tibbets and Joe Fait, among others).