Monday, May 22, 2006

Credibility! Tampers!

So far two readers of this blog have taken the time and consideration to write.

The first letter was about our "credibility" and how that "credibility" might be increased (or improved, I can't remember which) if we were to give our "real identity."

Having given it months of thought, I (rammed earth) have come to the conclusion that "credibility" is only an issue for two groups of people: those trying to sell and those wanting to buy.

The purpose behind this blog is to LIBERATE YOU from the ENDLESS CYCLE of DISAPPOINTMENT in the CREDIBILITY SWEEPSTAKES.

Thousands, if not millions of times a day, lonely consumers hit the streets looking for a credible merchant who's gonna treat them right! Millions more go looking for one who won't treat them wrong. Eager sellers splash on a little 'Old Spice' and hope their web of deception will dazzle these buyers into suspending their disbelief long enough to let go of their credit cards. The overwhelming majority (on either side) will be disappointed in that transaction--though not so much that they change their behavior.

That's not how we roll here. No nothing for sale here. I don't want your 16 digits and expiry date. This is a site where INFORMATION is SHARED. I urge you to take this information (and everything you read and hear, especially on the internet) with a healthy shovel full of skepticism.

Letter number two inquired about tampers, specifically if one tamper "does the job faster" than another. Here's what we know about tampers:

The Chinese did not use pnematic rammers and air compressors when constructing The Great Wall. The centuries-old compacted-earth structures that exist in myriad climactic and seismic zones were built with human-powered wood tampers.

While some would assert that a heavy, high powered ramming unit makes you feel you are really getting the job done, I would counter that one could build a rammed earth wall of excellent compressive strength with wood dowels, if your mix was right and your laborers energetic and concientious.

With that in mind, I would like to direct the attention of any interested parties to the products of the Henry Air Tool and Top Cat Service (Not like we're selling anything here...)

Both companies manufacture two models of sand rammer typically used to compact sand in foundry molds with identical model and part numbers;the 1350 and the 1320.

Our experience with the 1350 has been positive, they're light (14lbs) and easier to control and work around the form. The test results of core samples taken from walls tamped with these units had more than adequate strength (i.e. the rammers were providing adequate compression.)

For our next project we're going to try out their 1320 which is even lighter (11lbs) and has a shorter stroke (2" as opposed to 4") but delivers 1750 blows per minute over the 1240 bpm.

(Which one is "faster?" Stay tuned and we'll let you know)

According to Houben and Guilaud in their classic tome "Earth Construction: A Comprehensive Guide", the longer stroke is preferrable, though they specify 20 cm, double the length of the 1350s (which work just fine.) They also caution that "pneumatic rammers must neither be too powerful, as they might destabilize the formwork and cause the rammed earth to bulge".

I've heard of this happening recently, the rammers used were too powerful for the formwork causing the formply to bow, giving the resulting wall a quilted, tuck and roll effect. Using formply that is too thin can have the same result.

I'm also eager to try out a smaller 2 3/8" steel head for those hard-to-reach spots. Whatever you do, DON'T GET THE RUBBER HEAD, it will leave a mark on your formwork if you so much as brush against it when ramming. This mark be transferred to your wall surface, leaving an UGLY BLACK SKIDMARK which may be difficult, if not impossible, to remove without damaging the surface of your wall. Stick to the steel.




Don't kill yourself or your workers with heavy, unwieldy tampers. Less is More. Probably lower fuel costs too.

(But is it faster?)

Thursday, May 18, 2006

Now I Understand

If that drunk old high school guidance counselor of mind had done his job, he would have made clear that the reason why you go on to get things like engineering degrees (or law degrees) is because once you do, you are free:

1. Free from the burden of truth
2. Free from the burden of believing anything you don't want to believe
3. Free to be a ignorant time wasting moron.


A recent experience: two out of three structural engineers surveyed said: Rammed Earth Walls cannot be load-bearing
What kind of crap is that?
How is it that a licensed structural engineers in the year of our lord 2006, with computers, fancy wristwatches, business cards, plastic office furniture and the rest of the insipid capitalist accesories, be allowed to continue operations after they say out loud to paying clients "Rammed earth cannot support a roof."

STRUCTURAL ENGINEERS LISTEN UP! RAMMED EARTH WALLS ARE LOAD BEARING.

Here. Read this book. Cancel the golf game, put down the OxyContin, hold off on the cocktails till 11am--what ever it takes. Read the book and let's once and for all put to rest the preposterous notion that rammed earth can't hold up a roof.

Monday, May 01, 2006

Site Selection

Site selection is of course a central part of the building process. Choose wisely: once that rammed earth structure is built, there's no moving it.

As groovy as rammed earth is, make no mistake, it too leaves a huge (and messy) footprint where ever it is built. Plants will be killed. Ecologies will be disturbed. Cement (if you are using it) will go into every living pore of every living thing in the immediate vicinity. Petro chemicals will be spilled on the ground. Of that you can be assured.

So site selection is important.

If "wholistic thinking" is part of your personal narrative then why not get the "whole picture" as seen by people *not* of your culture, class and clique?

Feng-Shui continues to amaze and be ignored by all types of people. Is Feng-Shui (and site selection for that matter) simply a process of making a decision based upon feelings and intuition or is there (as in surgery or auto mechanics) something more to that process; an underlying logic and set of laws not immediately available to the neophite?

Says this website:


An Ideal Feng Shui location has a winding inward high mountain (Ying) at the background and a winding inward river (Yang) at the foreground.

Did you know this? Is it true? Are you at all even curious as to the (several thousands of years of) thinking behind this assesment? If Feng-Shui is good enough for Disney, might it be good enough for you?

N 51

"In keeping with traditional and contemporary rammed earth methods in Europe, no Portland cement was used in the rammed earth portions of the wall."

and...

"Rowland Keable and Martin Rauch, two leading rammed earth practitioners in England and Austria respectively, both claimed in independent interviews and site visits during June 2005 that the addition of portland cement was unnecessary in a properly detailed rammed earth structure if the natural clay content was high enough in the soil used for compaction."

That, along with some great photos can be found here at Joe Dahmen's rammed earth site.