Saturday, April 25, 2009

To Adobe or not to Adobe

Adobe elicits the kind of rhetorical rapture you don't generally hear about other construction materials like, say, cement blocks or aluminum siding.

"You can feel the warmth, the spirituality, the charm. It radiates! It has a round and soft feeling," one New Mexico builder raved about his adobe houses.

Close your eyes and adobe construction starts to sound like a cross between religion and sex, with a little yerba thrown in for added thrills.

Part of adobe's charm is its antiquity, like, as far back as anyone can remember. The pharaohs supposedly used it, and more recently so did Native Americans. New Mexicans seem to love the stuff and indeed Santa Fe architecture has been so adobified the city could be renamed Adobeburgh. The locals find it enchanting, though after a few days there, Stew and I found it boring. Adobe gas stations?

The recent rage over sustainable construction has given adobe added cachet. Its main ingredients are nothing if not sustainable and renewable: dirt, straw, a little water and some manure (the latter recently upgraded to asphalt to give the bricks added stability). You mix them, pour the stuff into forms and let it dry under the sun, another plentiful commodity in San Miguel. Pretty soon you have adobe bricks.

Just out of curiosity Stew and I went looking for the local adobe plant, about 15 miles out of town. The driving directions we got were typically Mexican--vivid, detailed and nearly useless. Next to a huge chicken farm? Nope, no adobe factory in sight. Across the road from a pig farm by a line of trees? Not there either, and by the way, those are horses, not pigs.

Finally, after 45 minutes of driving, we found the adobe emporium in the vicinity of some sort of a farm facility that may have contained pigs, chickens or goats. We couldn't tell for sure, so any one the three or four guys who gave us directions may have been right. Or maybe they were making things up and taking us for a ride.

A large man wearing a rancher hat and a nylon backpack, approached our truck and inquired about the nature of our business. I said we wanted to see how adobe blocks were made. "Imposible," he told me. We had to check with the boss first and he wasn't around.

The guy's secrecy and nervousness seemed amusing. After all, the facility was hardly an Iranian uranium processing plant. There was a pile of straw, another one of dirt and then a shed with open sides shielding piles of adobe blocks underneath. So much for the secrets of Mexican adobe-making.

Our decision to use adobe blocks to build our house came after some research and discussion with the architect. Ultimately it was equal parts aesthetics and our desire to build an energy-efficient home.

The almost universal building method in San Miguel is a skeleton of columns of concrete and rebar that holds up a roof also of reinforced concrete. Common red brick is then used to build the walls in between the columns. These bricks, known as tabiques, are cheap--about 10 cents apiece--and often sold from open trucks waiting by the side of the roads.

But at the hands of skilled Mexican masons, the lowly red brick can reach astonishing levels of beauty and craftsmanship. Many San Miguel houses have bóvedas or domes made out of bricks placed in concentric circles and capped with a nipple-like cupola with windows to let in light and air. The pattern of the bricks can be lineal, herringbone or a dozen other variations. The mystery of bóvedas is how the masons don't use any frames or other supports to hold up the bricks while the structure goes up and the mortar dries. Row after row of bricks goes up and then... I have no clue how those guys do it.

The advantage of brick is its low cost and ease of use. You can cut a local clay brick by whacking it with the side of a trowel. Half the adult men in San Miguel probably know how to build a brick wall, though applying the top coat of cement and doing it well is a far more specialized trick.

Brick, however, is a lousy insulator. During the summer, brick and cement houses seem to stay relatively cool, though the concrete roofs can retain the heat making bedrooms uncomfortable at night.

For Stew and me, the real downside of brick construction comes in winter when walls seem to be perpetually cold and clammy. Heating devices, most often gas fireplaces, fight with the cold brick walls but many rooms never seem to get evenly warm. That and the usual thin, single-pane windows make for very energy-wasteful structures.

Another option fast gaining in popularity in Mexico are AAC (autoclaved aerated concrete) blocks, which are lightweight, porous concrete blocks. Also called Hebel blocks, they have excellent insulating, sound-dampening and fireproofing qualities, all derived mostly from the air bubbles trapped in the concrete. Building crews have to learn how to work with the blocks, which are joined with a special adhesive, but once they master the technique the building goes up very quickly.

Drawbacks, yes, there are a few. One is cost, roughly about 80 cents a block according to our architect, some of which presumably can be recouped by the faster construction and savings in labor. Some enviros also point their collective finger at the high "embedded energy" in Hebel blocks. Compared to common brick, it takes a relatively high amount energy to make the cement, bubble it up and then heat it to get the finished product. It doesn't sound like a very sustainable building material.

Yes, but Hebel blocks give you much better insulation--and energy savings--than brick. Wouldn't that recoup the energy that went into making the Hebels?

Oh, boy. Now we're wading into the "six one way, half dozen the other" dilemma that you get into if you drag out some of these environmental computations and masturbations far enough.

No such fancy-schmantzy problems with ol' adobe blocks. Just dirt, straw, sun and the manpower to pile them up neatly to make a house. Embedded energy? Huh? Unless you count the gasoline for the truck to bring them to the worksite, there is none. (Hebel blocks, on the other hand, have to be shipped from a Monterrey plant in northern Mexico.)

Adobe houses are legendarily comfortable; inside temperatures remain within a narrow range throughout the year. The trick is adobe's ability to absorb heat and then release it at night. During the winter that locks the heat inside the living space; during the summer the reverse takes place, keeping the place cool. Or so goes the theory.

The adobe blocks in San Miguel are approximately 14" long, 10" wide and 4" thick and cost about 50 cents. I haven't actually weighed one but they feel like 10 pounds each and very dense. They are brittle and workers seem to handle them gently. Adobe is easy to cut or trim with a wood saw, a machete or other sharp tool.

We had the choice of leaving the outside adobe exposed or covering it with a top coat of cement. Stew and I opted for the exposed option, but with a sealant that gives the adobe a richer, darker hue. The sealant keeps the blocks from disintegrating under the rain and it has to be reapplied every two years.

Why exposed? We liked the earthen, more traditional look--particularly its expected contrast with the more modern contemporary details of the house--and the fact adobe will help the house blend in with the natural surroundings. In fact, from a distance, and even up close, the house blends in seamlessly into the landscape despite its bulk. We like it.

This is a shift for us, who started wanting to build a somewhat wild-and-crazy modern house, with some bright colors to boot. But the landscape surrounding our land ultimately won us over.

The cost of adobe was another "six one way, half dozen the other" deal. Piece by piece adobe is cheaper than Hebel blocks, but it goes up considerably more slowly. Particularly with an exposed exterior, quite a bit of cutting, fussing and finishing is required to put up an adobe wall, and judging by the scrap piles there seems to be quite a lot of waste. Our house has rounded corners which adds more chipping and trimming of the adobe blocks.

The extra work is manageable in Mexico because labor costs are very low compared to the U.S. I can imagine that building a fussy adobe house in New Mexico or Arizona, using $15- or $20-an- hour masons, could run into some serious money. Here our architect also specified inexpensive red brick interior walls to further reduce costs.

So our adobe abode is going up, though not as fast as we would like. There is a very warm, earthy feel to the stuff, accentuated by some of the curves the architect built into the design. A soft feeling, if you will.

Yeech. I'm starting to sound like a New Mexico housing developer.

Monday, April 13, 2009

Being There

When we broke ground for our house, friends who had built homes in San Miguel gave us a barrel of often contradictory advice, except on one point--you must be at the construction site every day. It sounded like an overly suspicious, even obsessive attitude to take. Two months into construction it turns out to have been an invaluable piece of advice.

To badly paraphrase Woody Allen, "90 percent of building a house in San Miguel is showing up at the building site, daily, and not being at all afraid to ask questions." If something looks weird, it probably is and you shouldn't assume the architect or the maestro will catch it, bring it to your attention, much less volunteer to pay for any make-up work to correct any errors.

This reality has nearly turned what used to be an exciting, fun process--building your dream house--into a stress-inducing grind. The same friends who told us to constantly keep an eye on things now counsel equanimity and constant recitation of the "Serenity Prayer"--you know, the ditty about "accepting the things you cannot change."

So far we've been through relatively minor, easily fixed screw-ups, like forgetting to put a door on an outside storage closet (we caught that when the adobe blocks were halfway up), or using common red brick on some outside walls, when we had agreed to use adobe, which offers better insulation.

Dismantling the adobe blocks from the door opening didn't cost that much--just an hour's worth of labor for one guy--but correcting the red brick/adobe switch probably wasn't quite that cheap. Some of the concrete footings had to be redone and widened to accommodate the wider adobe blocks, and a few of the rebar columns had to be repositioned on the new footings.

The debacle over the huge, rain-collection cistern definitely wasn't cheap. Designing such a monster should have required a relatively simple engineering study of the soil on which the walls would be built, plus a couple of hours quality time with a calculator or computer to determine stress, pressure and so on exerted by the weight and volume of the water. The latter would have determined the thickness of the walls and what reinforcement was needed.

Though there were blueprints that were handed over to the maestro on site, we don't believe any fine planning or forethought took place before the backhoe arrived. In the end, we suspect the architect opted for brute force--overbuilding everything by a factor of at least double, to be sure it will hold.

It will. I'm not losing any sleep over the possibility of the cistern sliding down the hill. I just wonder how much money and time we spent to compensate for the lack of more precise planning. I'm betting it was a few thousand dollars and a couple of weeks.

Stew and I never built anything from the ground up in the U.S., so we have no point of reference with which we could compare our residential construction experience in Mexico. It could be the same nerve-wracking experience wherever you build in the world, be it Mexico or Sweden.

However, Stew was the co-owner of a home inspection company in Chicago and he can spot quality construction or snafus when he sees them. So far he is baffled one day and resigned the next regarding the construction of our house. He's further frustrated by the fact he doesn't speak Spanish well enough to converse with the maestro.

One peculiarity we've found is the lack of complete blueprints before the project starts. In fact many people, include Americans, build without any blueprints at all, and just decide what work needs to be done when the sun rises each morning. The results range from perfectly fine homes, to idiosyncratic creations--Gaudi knockoffs with empty wine bottles encrusted in the masonry--to construction so inept it makes you nervous just to look at it.

In our case there were regulation-size blueprints, approved by the San Miguel building department, but no complete set of drawings. So although we have an idea of what the house will look like, a myriad crucial details remain in a fog.

There is some sort of a wiring diagram but that's just some drafting boilerplate an assistant in the architect's office cranked out on his computer.

I glanced at a plumbing and drainage plan but it can't be more than a rough draft: The second bathroom layout has yet to be finalized, and nobody knows where the water line from the well will feed into our famous cistern. The architect today pointed vaguely to some place on the garage side of the house.

In the U.S., a properly built house with building permits, qualified crews and so on, would start out with blueprints that show every orifice, electrical circuit and plumbing fixture in place.

A lot of improvisation is as it should be. There's got to be enough flexibility to move a door or widen a window if, when you see it about to be built, you decide that it doesn't work.

But much on-the-fly construction in San Miguel has to be inefficient and costly.

When a two-foot-thick stone and reinforced concrete wall, separating the cistern from the mechanical room under the kitchen was built, no one thought of placing a pipe that would connect the underwater pump in the cistern with the pressure pump on the other side.

So some poor guy will have to spend the better part of a day with a hammer and chisel, pounding through the stone and concrete to make the necessary opening. More chiseling will be needed to bring in electricity.

Other guys likewise will have to spend many days making holes in the concrete foundations to bring out the plumbing from kitchen and the bathrooms to the drain line that is going in somewhere alongside the house in the direction of the septic tank, whose location is also still unclear. An electric hookup for the kitchen island? Someone will have to chip away a connecting trench and hole in the concrete floor that's already been poured.

Although this is a gross exaggeration, it feels a bit like building a house with solid walls and then cutting out holes for the windows and doors as you go along, once you figure out where you'd like to have them.

It's one way of doing construction, but wouldn't it be faster and cheaper to figure those details beforehand and build them in as you go?

What drives a lot of this inefficiency and lack of planning has to be that labor around is dirt cheap. So mistakes are cheap to fix. A hammer-and-chisel whiz will cost you only about US$2.50 an hour, so if things get bollixed up and need to be redone once or maybe twice, you don't worry about it. The whiz, who'd probably be unemployed otherwise, will be grateful for the work too.

Besides, Stew points out that there seem to be few construction standards; in effect everything is custom-made. In the U.S. you need to allow for exact holes for windows and doors that are fabricated to standard sizes. In San Miguel the size of the window is whatever you say it is, right at the building site.

Such endless flexibility often causes problems. Where we live now, the dishwasher sticks out three inches out from under the counter because the "custom-made" countertop (made of concrete) is not deep enough. It is as deep as someone decided it needed to be.

That's not so bad as our friends up the hill, who had to buy a half-size dishwasher because the space under the concrete counter was not wide enough. So the machine now sits in a hole with six inches of dead air on each side.

Qualifications and training of the workers are another imponderable. Despite the miscalculation with the cistern, our architect has come up with what we think is a great design and we remain confident he is well qualified to execute it.

The guys working under him are a far more mixed bag. In San Miguel there's no such thing as a journeyman license or apprenticeship program for plumbers, electricians, carpenters or other tradespeople.

So you get who you get. The maestro at our worksite probably learned his trade by laying bricks, working hard and showing a bit more initiative than his colleagues. His brother works alongside him, and the maestro's 16-year-old son is already on the payroll as a laborer. Everyone in the family likely will end up a maestro sooner or later--without any formal training.

Except that building a house is clearly a complicated job, involving countless measurements, blueprint readings and judgment calls. Our maestro is very pleasant, reliable and hard-working, but he needs daily supervision, lest something go badly awry.

In more complicated tasks, like wiring a whole house, unqualified personnel could cause some serious damage.

In our present house, one in a relatively new condo development of 40-some units, the electric entrance panel consists of four 30-amp breakers that are grossly oversized.

A couple of weeks ago half the toaster's heating coils burned to a crisp and the breaker for the kitchen--which should have tripped instantly--didn't even blink. I mounted a metal wall lamp in the bedroom and discovered it gives a pleasant buzz, because the outlets may not be grounded. The wiring was probably done by an enterprising guy who worked in construction for several years and then decided to break out as an electrician on his own.

With no licenses or schools to teach a trade, who's going to say 'no'?

Much of the problem is that San Miguel, for all its charm and ideal climate, is a very poor and small venue, with a limited talent pool.

About two years ago a national supermarket chain built a huge store that went up so fast it seemed like a vision. Cranes, I-beams, drywall, concrete flying in all directions and swarms of electricians hunched over huge transformers and junction boxes. This went on day and night. The entire store probably went up faster than many houses in San Miguel.

A miracle? Not quite. Most of the tradespeople on the job, plus the architects and engineers, most likely came from the much larger nearby city of Queretaro or even Mexico City.

But let's not damn all construction workers in San Miguel. Along with some abominations, Stew and I have seen excellent work, notably carpentry. Tile work can be very good too as well as woven brick construction of bóvedas, or domes, and barrel ceilings that seem to defy gravity.

We hope to get to some of that fun stuff soon.

Meanwhile, our house is behind schedule, we hear, though we don't know how far behind. We never had firm completion date. Probably two or three weeks.

As for budget, the "reserve" money is already gone, and so are another $5,000 dollars or so, most of it tied to the cistern.

The good news that with the cistern behind us, the rest of the house should move along more swiftly. The architect also just completed a couple of big projects and promises to give our place daily attention. That gap may explain many of our problems.

A friend, one of those who built a house without the help of an architect, smiles knowingly at our litany of construction woe. His house cost twice as much as he had expected. He had other problems, he says, such as his maestro stealing the Christmas bonus pot intended for all the workers.

Things in Mexico are done differently, so get over it.

"Just be sure you don't work yourself into such a lather that it spoils the fun of finally moving into your own home," he said, smiling again.

Saturday, April 4, 2009

Some Trees Grow in the Rancho

Looking more like twigs than trees, about 30 saplings sway awkwardly in the arid, dusty and increasingly hot landscape of Rancho Santa Clara.

It's not an encouraging sight. These guys, some growing crooked, are practically invisible, scattered over the largely barren 7.5 acres of land. Amazingly, most are sprouting new leaves. At least three are definitely dead, even though I keep watering the dearly departed too, hoping for a botanical miracle.

Stew and I planted the trees six months ago, almost exactly at the beginning of the dry season during which zero rain falls for several months. We talked grandiosely about land reclamation schemes, contrasting foliage and clever designs to shield the land from future neighbors.

Duh. Planting those poor fellas at the worst growing time of the year instead revealed one of the worst weaknesses a gardener can have--impatience. I was afflicted with it in Chicago, where I used to put out tomato seedlings before the last-freeze date or watered or fertilized other things too much, hoping to speed up their growth. Yearly setbacks didn't seem to teach me anything.

One thing we did get right at Rancho Santa Clara was the selection of trees either native or accustomed to the harsh soil and conditions in this area. We consulted with a Mexican agronomist, who gave us a list of suitable native trees, though he charged us the exorbitant sum of US$500 for his efforts.

The tree selections were:

(5) Mexican Poplars (Alamo mexicano in Spanish). These are the fastest-growing of the bunch, though if they are anything like Lombardy Poplars in the U.S, they may not be very long-lived.

(6) Tejocotes. These natives also seem to be quite sturdy, with silky leaves that are green on top and silverish on the flip side. I've seen them fully grown and they are rounded and very attractive. Mine have a ways to go.

(4) Gravillea. Also very common. Two are alive and well, two seem headed for the compost pile.

(10) Pirules (Peruvian Pepper). Originally brought from Peru, pirules are now ubiquitous in San Miguel and central Mexico and seemingly indestructible. Their fine foliage is pendulous, somewhat willow-like. They can stand alone in the middle of a field, grow from a crack in the street, or on a rocky crag. After a nuclear attack pirules and cockroaches will be among the survivors. My kind of tree. All ten pirules I planted, about five feet tell, are very much alive.

(3) Jacarandas. Gorgeous trees that cover themselves with purplish flowers in late March, and quickly shed them to make room for lacy foliage. My three specimens--give them credit for courage and perseverance--tried to grow some leaves which were then nipped by frost early February. So they started growing again, this time from the ground up, which means I'll see purple flowers in, say, maybe 20 years. The agronomist did not recommend jacarandas; that was my idea.

(2) Tepozans. These are true natives, and the leaves were used by the Aztecs analgesics, sedatives and diuretics, for rheumatism and also to cures sores and exposed ulcers. One of mine is hale and hearty, the other one dead. Given their long medicinal pedigree you'd think these suckers would have been the last trees to croak.

(4) Pinus greggi. Common around here, with bright green, bottle brush-like foliage that is now covered with candles apparently in expectation of the rainy season. One fatality. Should get a few more of these.

(4) Casuarinas or Australian Pine. Has long needles and makes a whooshing sound at the slightest breeze. They're are supposed to be gorgeous when grown, which is a long way for me--mine are about four feet tall and not at all bushy.

The rest of the plantings are agaves, bougainvilleas and some climbers we put along the chain-link fence. Agaves went through a hard adaption after planting, making me fret that I'd be the first gardener to kill a dozen cacti in one fell swoop. In fact, I read later, agaves and other succulents should not be watered too much when a freeze might occur. The leaves plump up and can shrivel when they freeze. They struggled but seem to have made it, thank God. That would have been embarrassing.

The bougainvilleas are in hibernation, slowly coming alive though mostly from the bottom.

What have I learned from this mixed experience?

The first lesson is the hardest: Wait, in this case until just before the rainy season. Though the saplings are slowly leafing out, all they have done during the past six months is basically stay alive. We've watered them religiously but even that seems like a waste. Should have let nature take care of the water and acclimation of the trees.

Second lesson is also tough, though not as much so as waiting: Don't be so damn cheap. A bushy, rambunctious 12-foot tree is not that much more expensive than a puny pre-adolescent. Stew and I are in our early 60s, and if we want to to see the foliage combinations, lush green screens and all the other horticultural yadda-yadda during our lifetimes, big is the way to go.

Third is to judiciously prune off about a third of the branches. I did that, but only two weeks ago and already the trees seem to have responded by greening up and sprouting leaves in previously bare spots. Judicious pruning means keeping in mind the eventual shape of the tree so that it doesn't look like it got a cheap haircut. But prune you must. I should have done it earlier except the trees I bought looked so helpless (see my second point above) that pruning felt a bit like child abuse.

Pruning in this harsh climate might be particularly important. The wind is constantly blowing, stressing the trees in various ways, including by speeding water loss through the leaves. I should think that during the transplantation process there is some shock to the roots, including breakage. Pruning the foliage would compensate for any root losses of and restore the balance between the two.

The fourth point is particularly tough on the guy who plants the next batch of trees, who is not going to be me or Stew. You got to have large holes, which around here, particularly during the dry season, is a chore. The hardened black soil, so promising when wet, it almost impossible to work now.

I may have complicated the problem by hiring Don Francisco. Just by the use of "Don"--a title of respect used primarily on old guys like me, Don Alfredo--you can tell he was no strapping 30-something. Indeed, he was thin, slightly hunched and had a pointy white beard that curved forward and made him look a bit like a munchkin. What he lacked in youthfulness, though, Don Francisco made up by eagerness to work and effervescent disposition. He showed up at our gate asking for work. He was irresistible. How could I turn away such nice--if old--person?

I probably should have. I kept asking for deeper, wider holes that I don't think ever materialized. I think he should have thoroughly combined the soil he dug up with generous amounts of compost and tierra lama, a sandy type of soil used to keep the native black dirt from caking up when it dries.

Instead he essentially backfilled with the same dirt and rocks. I have read somewhere that there is a "tough love" school of tree planting. You put them in whatever soil you have and just mutter apologetically, "Sorry, but that's all we have," as you walk away. According to this expert, the trees will be better for it by adjusting more quickly to the difficult environment.

I may go the opposite direction next time, including (gasp!) some chemical nitrogen source. I had a bagful of soil tested by the agricultural extension in Austin, Texas, and the results were rather alarming. The soil at the ranch is sorely deficient in nitrogen, which would make growing trees, particularly fruit trees, a difficult job. Dousing the soil with chemicals is not a way to go long-term but it might be a necessary initial correction. Compost certainly is helpful in improving soil quality but its nitrogen content is not very high. I'm not sure.

What I should do immediately, though, is just wait. The rains should start in the middle of June, about ten weeks from now. That means we should start putting in more trees and plants in, say, seven or eight weeks.

That feels like a long time.

Thursday, April 2, 2009

Stuck in a hole

And a big hole at that. Cost overruns and delays are inevitable and two months into construction we've already been hit by both, caused by the construction of our extra-large rainwater collection system.

Was it actually necessary? Is it worth it? I must confess that I've had my doubts. Stew insists it will pay off in the long run.

As I have mentioned in previous blogs, we envisioned a cistern that would hold approximately 130,000 liters, or 34,000 gallons of rainwater. According to other local folks who have rain collection systems, that amount should carry us through an entire year without too many water conservation acrobatics. Our architect, who has quite a bit of experience building sustainable homes says we have enough roof space to collect 188,000 liters of rainwater in a normal year. Because of global warming (or whatever, don't want to start an argument about that with any Republican relatives and acquaintances) rainfall in San Miguel has been unusually heavy during the past two years.

We figured we would save on excavation costs by neatly placing it under a terrace that cantilevers off the living room. That would give us a wide but relatively shallow cistern, about seven feet deep. It might even save us money, we figured, because we would not have to dig a much deeper hole.

Then we ran into geology, soil and rock formations and other kinks. The top layer of black soil, about 18 inches to two feet, is tough as asphalt when dry but soupy mud when it gets wet. That's not prime foundation material.

So the architect decided to go deeper to ensure a sound footing. That's when he ran into tepetate, a type of brittle, light-colored volcanic rock endemic in San Miguel and other semi-arid and desert areas. Tepetate is a cousin of caliche, a hard calcium carbonate deposit found in New Mexico and other desert areas.

Blah, blah, blah. Whatever. The stuff is nasty.

Tepetate's only positive side, as far as I've been able to determine, is that a pulverized version of it can be used to pave rural roads relatively inexpensively. Just dump a few truckloads of it on the ground, spread it around sloppily with a backhoe, drive over it for a couple of months and then just wait for the rainy season. The result won't look like Rodeo Drive but it will be as tough as most road surfaces.

The only hitch is that it might wash off if you have a slope or drainage problems, but that's simple to fix. Just call one of a hundred purveyors--tepetate is as easy to find as corn tortillas--and tell them to bring a few more truckloads of the stuff and you're all set.

On the other side of San Miguel there is hardly any black topsoil, just straight tepetate the second you set foot on the ground. Digging a three-foot-deep hole to plant a fruit tree could well require a backhoe. Still, hardy souls garden and farm in this stuff, many with beautiful results.

Indeed, whenever I start to complain about our muddy black top soil at Rancho Santa Clara, my guardian angel taps me on the shoulder and goes: "Awshuddup! It could be tepetate!"

Because tepetate can be brittle--a stone-like chunk of it will crack and splinter when whacked with a sledge hammer--the architect had to dig a little deeper to find solid rock. That required extensive banging through the tepetate by a backhoe equipped with a jackhammer attachment at one end. Even the relatively new machine broke down repeatedly.

In the end we got our hole dug but it turned out to be a far more complicated and expensive project. The outside walls, made of field stones collected on site, had to be considerably wider at the bottom, I suspect to guard against any shifting. On the inside of the stone walls is another wall, about eight inches thick, of concrete reinforced with rebar.

One pleasant surprise, for San Miguel, is that the architect used concrete trucks and a snorkel to pour the concrete walls. At many, if not most, residential construction projects here the cement or concrete is mixed by hand in small mounds and then hauled in plastic five-gallon buckets to the waiting wood forms. Bucket after bucket, hundreds of them, carried on the shoulders of laborers, sometimes up to a second or third story, in a spectacle as primitive as it is slow and inefficient.

Wouldn't it be faster, and therefore cheaper, to use premixed concrete at all these sites? Faster yes, but probably not less expensive: Labor here is so cheap, and unemployment so high, that the cost of one cement truck will buy you a hundred hours of work, and you'll end up saving money.

And even if the building goes up faster using mechanized equipment, speed is not necessarily a prime concern in the San Miguel construction trades.

When we were pricing a chain-link fence to put around the property, I stopped at Ferretería Don Pedro, the local hardware emporium, and asked if we could rent a gasoline-powered post-hole digger, as an alternative to some guys digging hundreds of holes through the tepetate and rock by hand.

One of Don Pedro's young sons explained that equipment rental is not available here. And so he looked up post-hole diggers in a tool catalog of a foreign manufacturer. He seemed genuinely perplexed by my query.

"Why don't you just use a bunch of guys with picks and regular diggers?" he finally asked.

I replied, rather officiously, "Well, with a power digger the job would go much faster. Digging through all that rock will take forever, don't you think?"

Now more amused that puzzled, the guy just smiled. "I suppose, but what's the rush?"

In this case, San Miguel's logic won. Some fencing contractor put up our fence, using a crew of a dozen guys with manual diggers. I don't remember how long it took.

I'm not at all sure whether the massiveness of our cistern structure was the result of careful engineering calculations, or just a much cruder effort to overbuild everything--and then some--just to be safe. We know it has set back the construction schedule by about two weeks.

It hasn't saved us any money either. We may be down as much as US$10,000 by the time this rainwater hole is all finished.

In a way the cistern reminded me of the time Stew and I built a false ceiling at a building in Chicago. We didn't want to take any chances of it falling down on our heads and so we used enough two-by-fours to build a three-car garage. When a paunchy city building inspector looked at our handiwork, he shook his head and mumbled: "Well, one thing is for sure. This fucker ain't coming down."

And so may it be with our expensive cistern.