Now my dislike is nothing scientific. It just doesn't make sense to me. Sure it's relatively inexpensive, easy to put up, yields a continuous smooth surface, easy to repair etc. But I've seen so much bad sheetrock work, seen what water does to it, what fists can do to it! I've seen the dust from sanding, the tape, the mud...layers of complexity and monitoring.

It just seems to me that it is what it was meant to be: a cheap way to simulate a plastered wall! If you stop and consider how many sheetrock repairs you may have made over the life cycle of your house, the acoustic downside to such a wafer thin product, the dust associated with it all...you might start agreeing with me.

And to all of that, we add this tidbit from GreenSpec:

"Virtually ubiquitous in our buildings, gypsum board is widely seen as an innocuous building material. However, in the last decade, Chinese drywall has been linked with indoor air quality problems, while concerns have cropped up around waste from coal power plants and its links to drywall. 

Domestic manufacturers are quick to point out that gypsum board manufactured in the U.S. has not been linked to indoor air quality problems, but potential leaching of heavy metals and biocides included for mold resistance are among the issues that need to be addressed more thoroughly by the gypsum board industry."

Earth architecture gets my vote for all of the reasons mentioned above. It doesn't burn, doesn't harbor mold, bugs don't eat it, it dampens noise and for pete's sake will stop a .50 caliber round!

I say no to sheetrock, and yes to earthen walls!

It's been a while since I last posted as we've allowed the ceb test building to cure a bit. And we certainly learned a lot worth sharing in the process. For one, we produced unstabilized blocks and stacked them in the wall "green" right out of the machine. No worries there EXCEPT that we didn't factor in the small shrinkage that would occur in the drying process. No thinking of that prospect, we moved on to plastering the walls. That led to two lessons: 1. make blocks, allow them to "cure," then set blocks! 2. plaster only after blocks have cured. 

The best part of all, however, is the forgiving nature of this building process. Yes, our first plaster coat popped and chipped as everything dried. No problem. Enter Jim Hallock and his crew and 20 years of ceb and natural building experience was at our fingertips!

Jim graciously offered to lead a replastering effort after our team chipped off the first plaster layer.

Robbie, Jesus, "nooner," and Jorge applying the new scratch coat. This batch of plaster was fabulous with some tweaks from Jim and I now pronounce this crew "experts" in natural plaster!

Martin and David hard at work screening sand.

Jim surveying the half-naked building before he jumps up and details the door and windows.

And for the record, we're an "equal opportunity" plaster crew. A pregnant Lucia Blanco on the site, hawk in hand. No one loves natural plaster more than Lucia who is an architect with extensive experience in natural building techniques in France and Africa. Whisper the word plaster, click your heels three times....and basta! Lucia will be there!

We've hung plastic around the building while we "endure" copious amounts of Spring rain. No complaints about that after last Summer's drought. We'll be tackling a new finish coat, inside and out, in the next week or two.

Once again, our experience in ceb construction has shown us the value in the medium and the value in the spirit of community that exists. I have been grateful to have the input and guidance from so many experienced professionals like Jim, Lucia and Stephen Colley (local San Antonio architect.) I hope this is a great start to a new building tradition in our area. Our climate is perfectly suited for it to help manage heat and humidity.

We learned a great many lessons on material prep, staging, handling...a great deal on block "tweeking," etc...and even more on the plaster phase. I think it might be instructive for those of you following the blog for me to give a debrief in outline form on lessons learned. More to come on that.

I will have more pictures posted soon but will start with the set below. You can see our finished structure as it stands now. The deep overhangs gave us a nice framework for protecting our still-drying plaster from rain with plastic sheets. The roof design mimicks the multi family project specifications and has a big impact on our energy modelling. We get the added bonus of great protection for the walls from rain. The front (eastern exposure) has a 4 foot over hang, 3 feet on the back (western exposure) and 2 feet on either side (northern and southern exposures.) These orientations do not match our project site which will be 4 feet to the west, 3 feet to the east, and 2 feet to north and south. We're spec'd for exposed rafters etc. as you can see by clicking the thumbnail below which is a google sketch up model of our multi family project.

click thumbnail above for full size image

One huge lesson learned (and I dare say I was told as much but just didn't quite snap to) was how much more efficient our build would be by not integrating CEB into our door/window sections. That one front section seen in the photo above that included the door, window and polycarbonate panel infills had a multiplier effect on our time on the build that I feel will dramatically impact the economics of our future projects. Part of the goal was to learn, which we did, but also to start demonstrating the cost efficiencies and energy efficiencies (costs going forward) of using earth construction techniques like CEB. We have already started modifications to our plans to fit to the design and to reflect our build experience.

You can see Daniel hard at work here working out the details on the door and window section. Again, huge drag and inefficiency on this element. But then, that was the purpose right? To learn, calculate and reconfigure!

While my intention with the photo above was not to be artsy in any way, my unique angle does serve the purpose of illustrating several interesting elements. First was the tile Aurelio selected which I thought looked rather "cheesy" in the box....but ended up looking great on the floor. Just goes to show why I don't pick design elements and he should be nominated for some future Earth Architecture Design show!

One item of note is how the guys figured out that by rotating the blocks on their side, we ended up with a more stable wall section between the door and window that was just right for a 2 switch panel for lights. The opening for the box was created by cutting a block short to match the depth of the box, something they repeated in the walls to practice for electrical conduit and junction boxes for outlets. If you look closely at the photo above you can see a plaster variance about a foot off of the floor on the left hand wall surface. By cutting blocks 1 inch short on that course, and 3 inches short where junction boxes would be installed, we were easiy able to provide the necessary cut outs that could be plastered and hidden.

All in all a very worthwhile experience. Modifications ahead on this structure for demonstration purposes include removing sections of plaster inside and out and replacing with alternative treatments, completion on the passive ventilation design (worthy of a full blog post when completed) and the installation of data loggers by John Morony. We're all excited about the future data stream which I will figure out how to graph and keep updated.

You might notice the wall section half dark, half light. The dark section is where they sprayed the wall with water. Sprayed with water?! That's right...the lime plaster won't adhere to the building without a moist surface.

Speaking of plaster...here's a picture of David preparing a batch of traditional lime plaster. Beautiful stuff, really, comprised of sand, lime, marble dust, hay and, of all things, nopales cactus juice.

Someone needs to supervise the material prep...might as well be the boss!

Nopales cactus-infused water renders a natural and very effective latex. Sometimes I wonder if we invented solutions to problems we never had and materials that already existed!

And, finally, the plaster goes up. Beautiful in color, remarkable in texture and extremely effective in not only protecting the walls from the elements, but in maintaining the ability of the walls to "breathe." Referred to as latent heat flux, or the ability of the walls moderate temperature by absorbing and giving up moisture, this "breathing" is credited with a healthier interior air quality and with helping to keep the building cool.

And as the sun sets, the guys are still at it. In fact, they are STILL at it as i write. It's a great crew on the project with real commitment to a quality outcome. Sourcing materials, making and stacking blocks, plastering...all phases very labor intensive. I asked Robbie, the crew boss, if he had it to do all over again, would he prefer to go back to stick and stucco construction. His answer? NO! "This is a superior way to build...and results in a much better building...it's worth it." Amen!

With the bond beam in place, the roof rafters started taking shape. We have very deep overhangs specified for the roof, 3 feet over the short end of the structure, 4 feet over the front, and 2 feet to either side. This will help protect the building from the elements and provide a lot of shade around the walls. We're a hot humid climate zone so the shading is an important part of the passive cooling program.

Final roof details were worked out today and yours truly, the solar chimney man, just had to find a way to put all that great summer heat to use COOLING the structure. More details to come as that unfolds. 

The guys working on this project are developing some great skills and are showing talent in executing a loft style ceb structure. With the roof structure complete tomorrow, plastering can begin in earnest. A subject worthy of a post in and of itself. We'll be using a traditional lime and clay plaster ammended with nopales cactus "juice" which provides a natural latex to the mix. I haven't personally seen it, only had reports of how beautiful it looks. Looking forward to that part.

Something that weighs so much deserves a name I think....perhaps "la casita ocho" would be appropriate given it's location behind old fire station 8. Or maybe even "la gordita!"

It's no wonder then that our intrepid crew is tired and sore at the end of a long day of block wall construction. I've joked with them that they need to star in that gym commercial where the guy simply says, "I pick things up, I put them down!" 

You can see the crew below hard at work putting the walls up in earnest......

...with great progress toward our first goal of an eight foot wall section.

Through trial and error the guys put together an optimal system of material handling, block making, equipment positioning and wall construction. Lots of detailing decisions were made as the door and window sections were added..then removed...modified...and replaced. You can see one of the retrofits between the door and window bucks. We had originally placed a pilaster between the door and window of 2-3 blocks wide. That detracted from the loft style look we were after so the command came forth to remove the pilaster, bring the window buck closer to the door and to leave just enough space for a dual light switch. Easier said than done! Removing the blocks that had been set in place with slurry proved to be one heck of a task a mere hours after they had been set. It was a true testament to the solidity of this construction methodology. They succeeded in the task and found that a block laid on edge between the door and window bucks provided just the right amount of space for the light switch and preserved the integrity of the building shell in terms of it being all compressed earth block.

But what would any job be without equipment failure?! The bobcat blew a hydraulic line late in the day, slowing block production. The bobcat has proven to be an indispensible tool in moving and working dirt, then bringing it to the block press. Men or machines...an age old calculation! In this case, we love the bobcat!

And with the setting sun, we find Robbie, boss of the job, still hard at work towards his goal on the rear wall section. This section has the western exposure and will carry the greatest heat load. My intention is to set the fresh air intake grills in the corners on the floor on the western wall. I'm no engineer, but with solar chimneys at the roof peak on the eastern exposure I'm betting on very effective drafting of any heat that manages to find its way through 12 inches of compacted earth on this wall. Other passive cooling concepts will come later with landscaping. The pecan tree behind will also provide significant shading. In fact, so much so that mounting solar panels on the roof would likely not be a possible energy strategy for powering DC fixtures, something we had considered for research.

Solar chimneys and Persian wind catchers (bagdirs) are certainly nothing new. In fact, I saw a great example of a wind catcher at the Cal-Earth institute a couple of weeks ago on a visit to their site. I didn't expect to see that as part of their demonstration project and was thrilled to see a working example. Unfortunately I was there in winter and didn't get to experience how it functions in the desert heat. Our guide at the center, however, indicated that it worked extremely well to circulate a cooling breeze in the summer.

Our own Firehouse 8 has a superb set up for several solar chimneys and we'll certainly be integrating those into the passive cooling strategies planned for the building. Large ceiling mounting gas heaters used to warm the truck bays have been removed and we will be improving the vent pipes that lead to the roof to create natural convection of warm air off of the ceiling and out of the building.

Drawing hot air out, implies drawing COOL air in. That is the major design challenge we face. The Hawaii center illustration is a clever use of cold water and is a very interesting design. Simple earth tubes have been considered (nice write up here: https://www.thenaturalhome.com/earthtube.htm) but are generally discouraged for hot humid climates.

Watch for future updates on our solutions in this arena. The appeal of being able to draft a lot of fresh air indoors and improve air quality while cooling is very appealing!

Today we begin actual block production and laid the first few courses of blocks. After solving our dirt supply challenge (who woulda thunk it), the team got into a smooth rhythm. One of the objectives in this exercise is to train the team in all aspects of block making and block making, in addition to proper techniques for laying the blocks, working the slurry and blocking for door and window openings. It was an impressive start under Robbie's confident leadership and with technical assistance from the grand master himself, Lawrence Jetter. In many ways, today felt like a lot of prep, material staging, initial training and some baby steps into details that will serve us well for having practiced in preparation for the larger multi family project scheduled for first quarter 2012.

For this project we chose to use what I would refer to as a "purist" approach: unstabilized blocks, a very traditional slurry and final plaster coats with a lime plaster (more details as we begin that phase.) We had contemplated using a traditional Mexican green roof on the project but opted not to in order to practice the actual roof line and overhangs we have planned for the multifamily project, and after our calculations indicated approximately 60,000 pounds of weight attributable to the roof alone. A nervous construction crew convinced us that more advanced engineering would be in order for that!

Tomorrow sees an expanded work crew and block production in earnest...full steam ahead!

This interest originated with a question: "isn't there a better way to cool our homes and offices in the heat of the summer? What about controlling humidity?" And so it began.

This may be a bit like watching a movie that transpires in the present with flashbacks to the past. Today, we officially launched our building process with compressed earth block on a test structure. This test structure was designed to be a scale model to test detailing for our 14 unit apartment complex planned for quarter 1 2012. This will be San Antonio's first and only compressed earth block multi family structure. This test "shed" is designed to look like this:

The first step is to set the foundation. We will be using a dual footing foundation which was widely used by Frank Lloyd Wright and which he referred to as a rubble foundation. More details on that to come on a future blog post. The foundation trenches were dug at twice the width of the supporting beams and will be back-filled with one inch gravel. The extra width will help in ensuring proper drainage away from the building.

More posts to follow as the project unfolds over the next two weeks. I generate a great deal of interest around our efforts to build "green" and energy efficient using what some refer to as "post industrial architecture."