Alexander’s Distribution of Towns


In a recent post, I analyzed what it would look like to apply the first pattern of Christopher Alexander‘s A Pattern Language to North America. This pattern, titled Independent Regions, created 50 new, small nations or regions within what is today the United States and Canada. The next thing I wanted to try was applying Alexander’s second pattern, The Distribution of Towns, to one of those new regions. The pattern reads:

If the population of a region is weighted too far toward small villages, modern civilization can never emerge; but if the population is weighted too far toward big cities, the earth will go to ruin because the population isn’t where it needs to be, to take care of it.

Therefore:

Encourage a birth and death process for towns within the region, which gradually has these effects:
1. The population is evenly distributed in terms of different sizes- example, one town with 1,000,000 people, 10 towns with 100,000 people each, 100 towns with 10,000 people each, and 1000 towns with 1000 people each.
2. These towns are distributed in space in such a way that within each size category the towns are homogeneously distributed all across the region.

This process can be implemented by regional zoning policies, land grants, and incentives which encourage industries to locate according to the dictates of the distribution.

apl2diagramtowns of 1,000,000 – 250 miles apart
towns of 100,000 – 80 miles apart
towns of 10,000 – 25 miles apart
towns of 1,000 – 8 miles apart

However, as discussed in the previous post, not all regions that meet Alexander’s population criteria automatically meet his spacing criteria when you move from Pattern 1 to Pattern 2. Several regions are too large and sparse, while several more are too small and dense.

Click to enlarge.

Click to enlarge.

So to analyze Pattern 2 without worrying about redistributing the population of the regions until they were the right size, I wanted to pick one of the “Goldilocks” regions that is already about the right size. I went with the Washington DC Region.

Click to enlarge.

Click to enlarge.

Now for the distribution part. Let’s say that we have a region, Region A, with capital city City 1 in its center.Diagram1-01Alexander recommends one very large city per region, so we’ll assume that City 1 has a population of about a million and that it’s the only city of it’s scale in the region. Our first step is to identify our cities of 100,000 people. While Alexander recommended making these cities 80 miles apart, I used 72 miles to simplify the math a little bit. So we want to make sure that these cities of 100,000 are 72 miles from City 1, as well as from each other.Diagram2-01Next we want to identify our towns of 10,000. Again, I fudged Alexander’s math a bit, and identified towns that are 24 miles (1/3 of 72) from any larger cities or from each other.Diagram3-01And finally, we want to identify towns of 1,000 people, eight miles from any larger town and from each other.Diagram4-01That’s what it looks like in an ideal world. However, in the real world, we’re not starting with a blank slate, and rather than founding new cities that are perfectly spaced from DC, I wanted to identify existing cities located in the right place. When you do that, it looks like this:

Click to enlarge.

Click to enlarge.

What this technique doesn’t consider, however, is why cities are located where they are: largely, access to resources, and access to transportation. They aren’t distributed evenly across a landscape; they’re bunched up in the places that have access to mineral, agricultural or intellectual wealth, and places that have access to ports, railroads, and highways. Disregarding this truth about cities means that some cities that are not located the right distance away from one another can get hosed. Case in point, Richmond, a city of over 200,000 people at the center of a metro area with over 1.2 million, because it isn’t spaced correctly relative to DC, is relegated to the 10,000 people tier, meaning that a huge population would be resettled to areas like Tappahannock (current population 2,397) or Powhatan (current population 49) which are spaced correctly.

Also, by using Alexander’s spacing suggestions, one does not arrive at his suggestion for how many towns there should be. Based on this distribution, you end up with one town of 1,000,000, eight towns of 100,000, 45 towns of 10,000, and 319 towns of 1,000. That adds up to 2,569,000 people. But in the last pattern, we determined that the Washington DC Region would have a population of 8,917,843. So where are the other 6 million plus people living?

The answer to that actually comes from another pattern, number 5 in Alexander’s book, Lace of Country Streets:

The suburb is an obsolete and contradictory form of human settlement.

Therefore:

In the zone where city and country meet, place country roads at least a mile apart, so that they enclose squares of countryside and farmland at least one square mile in area. Build homesteads along these roads, one lot deep, on lots of at least half an acre, with the square mile of open countryside or farmland behind the houses.

Alexander doesn’t specify how wide this “zone where city and country meet” is, and if we’re got small cities every eight miles across an entire region, it would almost follow that these zones fill in the rest of the space between towns. If we take a square mile, and line it on all four sides with lots that are just over a half acre, we come up with 116 lots per square mile. If we multiply that by the average household size in the US of 2.58 persons per household, we get about 300 people per square mile in the countryside. If you multiply that by the 24,945 square miles covered by our region, you get 7,483,500 people. If you remove some to consider that a considerable portion of our region is the Chesapeake Bay and that some of those 24,945 square miles are already taken up by towns and, therefore, the Lace of Country Streets wouldn’t apply, it basically adds up to the rest of the people we were looking for.

So what we end up with is a pretty even population distribution across the entire region with a bit more concentrated in the many small towns and a lot more concentrated in the few big cities. but is this even distribution good for people or for the environment? I take issue with part of Alexander’s rationale for this pattern:

Two different necessities govern the distribution of population in a region. On the one hand, people are drawn to cities: they are drawn by the growth of civilization, jobs, education, economic growth, information. On the other hand, the region as a social and ecological whole will not be properly maintained unless the people of the region are fairly well spread out across it, living in many different kinds of settlements – farms, villages, towns, and cities – with each settlement taking care of the land around it. Industrial society has so far been following only the first of these necessities. People leave the farms and towns and villages and pack into the cities, leaving vast parts of the region depopulated and undermaintained.

But what does it mean to “take care of” and “maintain” the countryside? It seems to me that the countryside does pretty well without us up in its business. Alexander mentions the ecology of the city and how large cities are bad ecologically, but (a) some of Alexander’s patterns that I will discuss later address that and (b) by pulling people away from the countryside and concentrating them in cities, it allows for the countryside to function as what we need it most for (a carbon sink), and allows people to take advantage of shared walls and transit systems which greatly reduce our per-capita carbon footprint. If it were me, I’d distribute the population more like this:

Click to enlarge.

Click to enlarge.

Making all the big cities even bigger and, most importantly, denser, and leaving only small villages sprinkled throughout the countryside. As long as enough people live out there to grow the food and operate the mines for everyone else, there’s no reason to have everyone flung out across the landscape. The best thing we can do for the countryside really is to leave it alone. As far as getting people access to natural environments, we’ll talk about that soon, when I take a look at Alexander’s 3rd pattern, City Country Fingers.

A Study on Regional Governments Part III: Back to North America


I’ve been working on regional governments on and off for several years, and this time I feel like I’ve made some progress. There are a number of reasons for subdividing North America into new regional governments, as I’ve already discussed in Part I and Part II. But the main idea comes from architect and known crazy person Christopher Alexander‘s book A Pattern Language, a book about development and building patterns that goes from the very large to the very small scale. The very first pattern in the book is:

Metropolitan regions will not come to balance until each one is small and autonomous enough to be an independent sphere of culture…

Therefore:

Wherever possible, work toward the evolution of independent regions in the world; each with a population between 2 and 10 million; each with its own natural and geographic boundaries; each with its own economy; each one autonomous and self-governing; each with a seat in a world government, without the intervening power of larger states or countries.

This time I tried to be more official and used a GIS to do my work rather than Google and Wikipedia. In the past I’ve used counties as my basic geographic and population unit, but that was problematic, seeing as Los Angeles County has over 10 million people already. It’s also problematic to go down to the level of cities, towns and places, because then you run into 8 million-strong New York City, and the second you lump in any of its suburbs it puts you over 10 million. This time I went in between and used county subdivisions, which will both divide Los Angeles County up as well as take advantage of the fact that New York City, while being one city, is also five different counties.

I also used information from both the US and Canada. Initially I wanted to do Mexico as well, since there are a number of major cities on the Mexican side of the border that draw people in from the US. However, I figure that the ties between the US and Canada are much stronger and that it would be easier to integrate their populations. Also, the fact that the US and Canada make census data and GIS files fairly easy to obtain while Mexico doesn’t might have something to do with it.

My methodology goes something like this. Let’s say you’ve got Country A with Cities 1, 2, and 3 and a population of 30 million.

Process1City 1 and City 2 are the largest cities in the country, so the country would be divided between these two cities.Process2Region 1’s new population is 18 million and Region 2’s is 12 million. Since Region 1 is the larger of the two and since it is still above 10 million in population, it needs to be divided again. The second largest city in Region 2 is City 3, so new boundaries need to be redrawn between that and the two existing cities.Process3The new Region 3 took 8 million people from Region 1 and 2 million from Region 2, giving all three regions a nice round population of 10 million. At this point we no longer need to subdivide them any further.

Of course, when you do this on real land and using real borders, it doesn’t come out quite as clean. It looks a bit more like this:

Click to enlarge.

Click to enlarge.

TableThe largest metropolitan area in Anglo-America is New York City and the second is Los Angeles, so they became the first two regions. Since they were both over 10 million and New York City was the larger of the two, Chicago was the third region, then Dallas, then Philadelphia, etc.

What is apparent in this exercise is that, since the regions are based on population and not geography, the size of the region correlates to population density. The densest parts of Anglo-America, the northeast seaboard and southern California, have the smallest regions, while the sparsely populated Rocky Mountains and northern Canada have enormous regions. What I haven’t realized in past iterations of this project is that it complicates Alexander’s second pattern, the distribution of towns:

If the population of a region is weighted too far toward small villages, modern civilization can never emerge; but if the population is weighted too far toward big cities, the earth will go to ruin because the population isn’t where it needs to be, to take care of it.

Therefore:

Encourage a birth and death process for towns within the region, which gradually has these effects:
1. The population is evenly distributed in terms of different sizes- example, one town with 1,000,000 people, 10 towns with 100,000 people each, 100 towns with 10,000 people each, and 1000 towns with 1000 people each.
2. These towns are distributed in space in such a way that within each size category the towns are homogeneously distributed all across the region.

This process can be implemented by regional zoning policies, land grants, and incentives which encourage industries to locate according to the dictates of the distribution.

apl2diagramtowns of 1,000,000 – 250 miles apart
towns of 100,000 – 80 miles apart
towns of 10,000 – 25 miles apart
towns of 1,000 – 8 miles apart

The last part of that section, which describes the spacing of towns, leads to a specific size that a nation of a given population should be. I experimented with a few town distribution models and determined that based on a combination of Alexander’s population and town distribution recommendations, a region should not be less than approximately 30,000 square miles, without being more than approximately 130,000 square miles. Several of the regions I’ve created based on population alone are either too large or too small to meet these criteria.

Click to enlarge.

Click to enlarge.

So to comply with Alexander’s recommendations, the small regions would have to have their population distributed more sparsely and their boundaries enlarged to accommodate that lower density, and the large regions would either have to become smaller and more dense, or have their populations concentrated in certain areas while others are left as uninhabited wastes, as is essentially the case in much of the mountain deserts of the western US and the arctic regions of Canada.

While I see the value of Alexander’s argument for smaller governmental units, I find his arguments for the distribution of towns a bit more dubious, especially when it comes to areas that are too dense for his recommendations. I generally feel that the best way to preserve undeveloped land is not to distribute people evenly across it, but to concentrate them all in one area and leave more of the land untouched. That’s why New Yorkers are some of the greenest people on earth; they leave the countryside alone, and are packed dense enough that they don’t have to use cars and take advantage of the energy savings of dense housing, making their environmental impact considerably lower than someone in a lower density area.

That being said, at some point I would like to take one of the Goldilocks regions I’ve created like San Francisco or Pittsburgh and try to create a distribution of towns like what Alexander recommends, just to see what it would look like. But as far as drawing new regions goes, I’m pretty happy with this version, and I don’t see myself redoing this project again.

A Study on Regional Governments Part II: the British Isles


I haven’t posted in a few days because I’ve been completely wrapped up in this project. Hopefully today and in the coming days I can make up for it a bit with some original content. For starters, I wanted to revisit the idea of regional governments.

I am still a big fan of Christopher Alexander, despite the fact that I’ve talked to a number of people who have met him in person and say he’s basically insane. In his most well-known work, A Pattern Language, the very first pattern is “Independent Regions,” where Alexander says:

Metropolitan regions will not come to balance until each one is small and autonomous enough to be an independent sphere of culture…

Therefore:

Wherever possible, work toward the evolution of independent regions in the world; each with a population between 2 and 10 million; each with its own natural and geographic boundaries; each with its own economy; each one autonomous and self-governing; each with a seat in a world government, without the intervening power of larger states or countries.

Alexander lists a number of reasons for this conclusion, including that a citizen of a smaller nation like Denmark can have direct access to the Minister of Education, while in a large country like the United States this is impossible. This, combined with my own opinions about the arbitrariness of state and county lines and the modern reality of metropolitan economies led me, a few years ago, to undergo an effort to redraw the entire United States based on regions of 2-10 million people.I produced three maps, including the one above (which I redrew once I learned something about design and how awful my colors were), which showed what the country would look like with minimums of 2 million, 5 million and 8 million. The problem with using minimums was that many regions ended up way over the 10 million mark. Los Angeles County, for example, has over 10 million people in it already, and when you add the surrounding counties which couldn’t form their own regions, Los Angeles became enormous.

The way I came up to address this was, instead of starting with all the towns in the US with over 100,000 people and seeing which ones could amalgamate 2 million people, I thought I would try another technique. I would start from the top, with America’s largest cities, and assign areas to them, based on which city it would be easiest to walk to based on Google’s walking directions. Once an area had been assigned, if it was more than ten million, I would take the second largest city in the assigned area and re-divide it; Thus, New York would start with 300 million people, but then be divided between New York and Los Angeles. The half of the country covered by New York, would still have the most people, so the next division would be Chicago, then Houston, etc., until each region had less than 10 million people.The problem is, the United States is an enormous country, with over 3,000 counties, and dividing the country county-by-county takes a very long time.

Another major issue I came across was that, just as state and county boundaries are arbitrarily geometric, so are our national borders. It is silly to think that, just because there is a line between them, that Mexicans don’t participate in the economy of El Paso, or Americans in the economy of Vancouver, or Canadians in the economy of Buffalo. So to really create a model that would take into account the realities of economies that straddle current international boundaries, it would be necessary to incorporate multiple nations, or even the entire continent, because when you get down to it, the hardest borders we have are oceans.

I wasn’t ready to attack that sort of a project yet, so I wanted to work on a pilot; I needed something that was smaller than the US, but still fairly urban, that was completely surrounded by water. I decided to test my new technique on the British Isles.

The British Isles consist of a number of islands, the principal ones being Ireland (Eire) and Britain. Politically, there are two sovereign states in the Isles: the Republic of Ireland, covering most of the island of Ireland, and the United Kingdom, covering Britain, Northern Ireland, and most of the other islands in the Isles. The UK is further divided into four constituent countries (England, Northern Ireland, Scotland, and Wales) and three crown dependencies (the Isle of Man in the middle of the Irish Sea, and the Channel Island dependencies of Guernsey and Jersey). Each of these countries and dependencies are largely responsible for their own internal affairs (all except England have their own elected legislatures; England’s internal affairs are governed directly by the UK Parliament), but international representation and defense is managed by the UK. Although this is certainly closer to the model supported by Alexander, some regions are too large (England especially), while others, the dependencies in particular, are too small.

From wikipedia.org.

Municipal government in these countries is, in many ways, similar to that of the US: In Ireland, Scotland, and Wales, the country is divided into counties which then are made up of parishes (cities and towns). Northern Ireland’s traditional counties have been subdivided into smaller districts, but the principal still holds. England, on the other hand, is a bit messier. It is divided into nine regions, which are then divided into two types of counties: metropolitan (for the more urbanized areas of England, such as Birmingham and Leeds) and non-metropolitan (less urbanized). These counties are divided into districts, and then into parishes. In addition, there are a number of “unitary authorities,” which work similarly to the independent cities of Virginia. Greater London is it’s own beast, on an administrative level similar to that of a county. The map I decided to use features counties, metropolitan districts, and unitary authorities.

Administrative divisions of the UK. From wikipedia.org.

I should point out that what follows is mostly a geographic experiment. Differences in linguistics, religion, and history were not weighed. Some of the boundaries in these countries are where they are for very good reasons, and many residents of Ulster may not want to be lumped in with the Republic of Ireland, or people west of Offa’s Dyke may want to remain in a united Wales despite being closer to English Liverpool than Welsh Cardiff. That being said, the geography may show things differently.

With this more top-down method, the larger regions emerged first, so the first thing that came up was a set of regions less than 10 million people:

I think that this map does a fair job of reaching Alexander’s goals. It coincides well with many of the traditional regions of the Isles: Ireland, Scotland, Northeast and Northwest England, the East and West Midlands, and the Southwest are well defined. There are some anomalies. First are those caused by ferry services between the islands. For instance, while Dublin is geographically the closest major city to Belfast, it takes much less time to take a ferry between the two cities than to walk. However, if you’re already taking a ferry, it takes less time to ferry from Belfast to Liverpool than to Dublin. By the same token, it takes less time to ferry from Anglesey in Wales than to walk to Liverpool. In reality, these anomalies probably wouldn’t exist.

Another interesting thing is the smaller cities around London. Unlike in the North, where major cities form a string from Liverpool to Manchester to Sheffield and Leeds, London is sort of on its own, and it falls on smaller cities such as Luton to create regions around it. This is most pronounced with Woking, a town of just over 60,000 people, and not even the largest in its region (Reading is much larger), but the largest that could anchor a region of 2 million. It would be interesting to see what would happen to these cities if they were given a larger administrative role.

The largest city that really gets the short straw in this analysis is Bristol. At about 430,000 people, Bristol is one of the top ten cities in the UK, but always ended up on the wrong side of the dividing line. It started out being a part of Birmingham, but when Southampton split off from London, it got sucked into its sphere of influence. It is hard to say if something like this would happen in real life.

Next, I took these regions and subdivided them until the subsequent regions were either less than 4 million and thus couldn’t be divided into two regions of 2 million, or when, even being above 4 million, it was impossible for the second city in the area to support a population of 2 million. For instance, so much of the population of Ireland is based in Dublin and its nearby coast that the second largest city, Cork in the west, was unable to amass the 2 million needed to be a region.

Some of the anomalies from the first map go away, while news ones arise. By creating a Belfast region the ferrying issues on the first map go away. However, Anglesey is still closer to Dublin than Liverpool. The introduction of Cardiff also creates a Welsh region, although much of the north is still closer to Liverpool. Bristol still draws the short straw though, as it is now shifted into Cardiff. The problem of small cities that are really part of a larger region spreads from London to Birmingham, where Wolverhampton forms its own region when really it is very much a part of greater Birmingham. The North is generally much more fractured. This is also the first time that the unitary authorities pose a problem; for instance, Derby is closer to Leicester, while Matlock, the administrative center of Derbyshire, is closer to Sheffield. In all, I think the larger regions better reflects the reality on the ground, the creation of Welsh and Northern Irish regions notwithstanding.

Even in this case, there are some if the same issues with international boundaries. For example, the Channel Islands are both closer to France than England. Would it be better for them to be administered by France? What about the Faroe Islands, administered by Denmark but much closer to Scotland? These questions notwithstanding, I think I’ve learned some things for another American experiment; work with maximums, but don’t worry too much about getting down to 2 million; just getting past 10 million will get you pretty far.

Milkweed: Park Dweller or Beach Bum? There’s Only One Answer if You’re a Fan of Green – Design Milk


Grand Park in Los Angeles. From design-milk.com.

This post from Kara Bartelt describes some of the great features of Los Angeles’ new Grand Park, and why the author would rather go there than to the beach. There are six reasons she prefers this new park:

Movable furniture – The bright pink furniture at this park is making a bit of a splash before the entire thing is even done. It’s important to have furniture that moves so that people can set it up just right considering their situation and climate.

Curated plants composing a well designed landscape – landscaping can be used to divide spaces, teach people about the environment, and give dogs a bathroom.

Well-crafted materials and construction – Parks need amenities like benches and tables, and they need to be built to withstand the test of time.

Private places – parks can have special nooks, seating areas, or other places that allow for a semi-private atmosphere.

Public places of community – Parks need places where people want to get together and do things. A good place to start with this is the Project for Public Spaces’ Power of 10.

View/scenery beyond its extent – The author points out that the beach often beats parks on this one. It’s important to have a view from any public space into something greater, or, as Christopher Alexander puts it, a hierarchy of open space.

This park has all of these features, and hopefully it will be a great new public space for Los Angeles.

Latest trend in house design: “A home within a home” : TreeHugger


New floorplan from suburban builder Lennar Homes featuring a secondary unit. From treehugger.com.

Lloyd Alter of Treehugger posted this earlier this afternoon and Twitter exploded. He shows a number of floorplans, including the one above, from Lennar Homes which include secondary units for “homeowners with adult children or elderly parents who want to live in the same household as their relatives without sacrificing privacy or convenience.” This is an interesting adaptation to changing conditions; this caters to the fact that a lot of college graduates are having trouble finding jobs and are moving home, but also to the fact that the multi-generational family, once common but not so much today, is coming back, partially through immigrants who are used to living that way and partially through financial necessity. This is exactly something that Christopher Alexander advocated in A Pattern Language. He encouraged homes to develop different units, or “cottages,” for both teenagers and the elderly within a family, with the express idea that they could be rented out when not in use by a needy family member. These sort of “mother-in-law apartments” are fairly rare in many suburban areas, but have been a part of New Urbanist developments since their inception. Alter questions whether cities will regulate these sort of houses to make sure that only family members live in the second unit, but it is a step in densifying the suburbs, and potentially bringing them towards urbanity.

The 38 States of America


The 38 States. From tjc.com.

Someone recently posted a link to this map and it’s accompanying explanation on my old blog as a comment on my regions project. I know that I’m not the only person to think about how meaningless state boundaries are in the United States, but I was unaware of this effort by C. Etzel Pearcy. It may be the most thorough I’ve seen. Although some of the regions would not fit Alexander’s criteria for independent regions (the ones in California, Texas and New York, to name a few, certainly have populations over 10 million), it is an interesting effort.

The Concrete Chronicles – Part 1


As some of you who are closer to me may know, or those of you who read this blog consistently, I am a really big fan of Christopher Alexander, and especially of his book A Pattern Language. The book can teach you how to build practically anything, from a country to a doorknob. However, once it gets into the idea of actual construction, it focuses a lot on the use of lightweight concrete, which has about the weight and density of wood, but is many times stronger. In pattern 207 (Good Materials) of A Pattern Language, Alexander encourages the use of concrete “whose densities lie in the range Of 40 to 60 pounds per cubic foot and which develop some 600 to 1000 psi in compression…a range of mixed lightweight aggregates, containing vermiculite, perlite, pumice, and expanded shale in different proportions, can easily generate 40-60 pound, 600 psi concretes anywhere in the world. We have had very good luck with a mix of 1-2-3: cement-kylite-vermiculite.” Since this pattern is so fundamental to the basic construction of nearly anything in A Pattern Language, I decided to experiment with lightweight concrete.

Preparation

The first problem I encountered was that there appears to be no such thing as kylite, one of Alexander’s recommended aggregates. All I could find on the internet were other people quoting Alexander and adds for skylights (Put an “s” on the front and misspell it, you’ll get there). So I went looking around for other lightweight concrete formulas, and found out for the most part that Alexander’s formula still stands if you just replace kylite with sand. I also found that vermiculite and perlite are more or less interchangeable in these formulas, so I wanted to get both so that I could compare their properties. Based on a few different sources, I came up with a recipe of two parts cement, four parts sand, six parts perlite/vermiculite, and three parts water.

Perlite is used as a garden aerator and is actually fairly easy to find at any garden store. Vermiculite, on the other hand, was not so easy to find. According to Home Depot’s website, there are two stores out of the dozen or so in the Philadelphia area that sell vermiculite, neither of which are the ones that are reasonably close/transit accessible. So the next step for me, since my license has expired and I am therefore not legal to drive or use PhillyCarShare, was to find someone willing to drive me to the Upper Darby Home Depot to pick everything up. Eventually Brad Packer from the ward volunteered, and this morning we set out for the store.

At the store, we went and got a 2×4 cut into 30-inch sections with a six inch block left over. We found three cabinet hinges and two clasps. These all would be used to make the concrete form. We then got a bag of sand and a box of cement. I would like to point out that I am quite happy with my purchase of Cement All, partially because they were one of the few manufacturers that sold it in packages that were less than 50 pounds, and they also have a carrying strap and a resealable package, which is great for non-contractors like myself. We headed back to the garden section and…no vermiculite. Apparently Home Depot’s website is full of lies. But they had plenty of perlite, so I grabbed a bag of it and we loaded up the car and took it home.

Assembly

I first cut the last six-inch block into four inch and two inch sections. I then took the four-inch and two of the 30-inch sections and attached them with hinges to the third 30-inch section. This is so that when the concrete is dry, the sides can fold down for easy release. I left the two-inch block unattached so that it can be moved to create sections of different lengths. I put the clasps on the end of the assembly to hold the sides up while the concrete dries.

The concrete form.

By the way, I pretty much did all of this in my kitchen. More on that later.

I then rinsed out a gallon milk jug, quickly made a funnel from a piece of printer paper, and poured my cement and sand into the jug. I then got out a real funnel and added the water, because one of the columns I had read said that it was important to mix the other ingredients first and then add the perlite. Perlite is a really interesting material. It weighs next to nothing and looks like something between corn snow and Styrofoam balls. I added this into the jug, put the lid on, and mixed vigorously for two minutes or so.

My cement mixer.

I started pouring the mixture into the form, and after I got impatient cut the top off the milk jug to speed up the process. The cement came out in thick, heavy globs. The concrete was so thick that it wouldn’t slide down into the form on its own, so I quickly squished my paper funnel into a paper trowel to level it.

This is a real professional job here.

All in all I filled a space about 27 inches long. And then I waited.

Letting the concrete set.

Results

The cement I used was “rapid set,” and was supposed to be set in 15 minutes and cured in an hour (a really exceptionally short time since most concrete can take days or weeks to fully cure). After about three hours, I busted open the form.

See, that’s why I put hinges on it. Pretty cool, huh?

I started tapping the concrete with a hammer to loosen it, something that any wood would stand up to, and a section about eight inches broke off at the bottom. This didn’t bode well. I had two tests in mind to examine the density of the material: the nail test and the saw test. In both cases, the material was, if anything, considerably less dense than wood. The nail went in quite easily.

Simple drywall nail in concrete. Sorry for the bad image.

The saw in particular was very telling. My saw is fairly dull, and it took me more effort than I would have wanted to cut the six-inch wood block into two. My saw went through the block like it was cardboard before it split after I got through about two thirds of it.

The broken block. The solid gray part is where it broke without the saw touching it.

It was around this point that I read the warnings on my box of cement which said something along the lines of “do this in a well-ventilated space with a lot of safety gear or else you’ll get cancer,” so I took the remainder of the operation out onto my deck. The main portion of the block was stuck fast to the form, and as I hammered it to get it to come off, it was like hitting a well-built sandcastle. This stuff was nowhere near hard enough to build a house out of. When it finally came off, I took it in one hand and gave it a good solid whack with the hammer. It broke right in half. No two-inch wooden board would break that easily.

What a mess.

Lessons for next time

  1. Go outside!
  2. I feel that I may have been impatient in only giving it three hours to cure, despite the assurances on the box. Next time I will try giving it a solid 24 hours.
  3. Later research into Cement All showed that their product already includes some sand. This could be why the concrete initially came out so globby. I may try replacing the four cups of sand with four more cups of Cement All and see what happens.

That’s all for now, but don’t be surprised to see another edition of The Concrete Chronicles very soon!

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