Like the Terracotta Army

Standing like figures from the excavated Chinese Terracotta army, our compressed earth blocks- formed from the very ground around our home- stand ready to be placed into service guarding our interior space from the environmental hazards outside. When faced with foam and stucco, the walls are about a foot thick with an R value of 50. They also provide thermal mass to our house, helping to keep it at a consistent temperature. The top blocks are dark because they were just rained upon. It's good to keep the blocks damp to allow the cement that gets mixed and pressed with the earth to cure.

The Master Mind - John Spears

Here's a shot I took today out at the property of our architect, John Spears. His company is called the Sustainable Design Group. He's been a pleasure to work with. We seemed to be on the same wavelength with him from the first time we met. Like any good architiect, he's thought about things enough to have informed opinions on things, but he is pragmatic, and has demonstrated a consistent effort to produce an attractive, functional, energy efficient, healthy, and affordable house for us. He loves to experiment and continually find new solutions to architectural problems. He has a very comfortable and energy efficient house of his own, along with a separate office/studio building. It's a real blessing that he's located only about 5 miles north of us in Gaithersburg.

Update May 30th

Here's where we stand today. The first floor deck is just about complete. We should soon be able to move around and build the exterior walls by setting earth blocks in place. The trash dumpster on site is starting to fill with cement bags, water bottles, protective plastic, pieces of cinder block, and now carpentry scraps. We'll have to order a "pull" soon to get a fresh one.

The support columns are nearby, still needing to be installed. They will hold up a pretty heavy house. Tomorrow the CEB crew will be back at it around 6:30am and will work until it looks like rain. Thunderstorms are forecast for the afternoon. We'll work to cover the cover the deck with large plastic sheets before it starts.

May 29 - How Did He Do It?

Meet Anilton Rezen. He's our framing carpenter. He's been in the business for about 20 years, and has framed various Winchester homes in Hadley Farms where we live now. Could it be that he has actually worked on our old home as well as our new one??!! Very possible and very amazing! What's also amazing is that our foundation guys, our CEB crew, and now our framer are all Brazilian. Maybe Michael can recruit some of them for his soccer team - they really love the sport.

Anilton's assignment for this week is to get the first floor deck on the house. Don't ask me how he did it, but these amazingly large and heavy steel beams lying in the weeds this morning were set in place by the afternoon. As I was standing there talking with him this morning, Smitty's lumberhouse brought by another load of lumber - just what Anilton was waiting for!

One of the other things Aniton's crew is doing is placing window "bucks" in the window openings. These are sized to take the windows. Our new home will have lots of windows, so this I'm sure of: we will definitely need a few more bucks to complete the job!

Daily Update - May 28th

Here are four shots I took on my way home from work today. The first is of a new Green Machine that was brought to the site today- a more powerful and reliable one than the one we started with, which seemed finicky, and actually broke down a few times. The new one is much better. The crew has learned which soil from the site makes the best bricks too, so today's bricks (second picture) are noticeably more uniform than yesterday's.

The foundation crew was also on site pouring concrete into the cinder block walls. They pour down the holes every 32" or so and drive a piece of rebar down the length of the wall. The last picture shows some of the finished area. This concrete will set up overnight, allowing for the framing carpenters to begin adding the first floor deck tomorrow. Maureen ran over to the site this afternoon to meet and pay the guy delivering the steel poles that will help support the house from the basement. She marveled at how he could back his big rig all the way from the Denit Estates Drive cul de sac. I guess he was afraid he wouldn't be able to turn around once he got to the work site.

Tomorrow the CEB crew will continue pressing out blocks and setting them aside to cure. The team is very efficiently sized for what its doing now, and I have to say that adding volunteers or other paid workers at this time probably wouldn't make the job go any faster. Where we'll need extra help is when the first floor deck is on, and we begin carrying blocks to the wall, while continuing production. We'll know better tomorrow or Friday, but it looks like the first day this could happen may be Saturday.

How to make a CEB

You start with dirt. It turns out the best quality dirt for making CEBs at our site is a clay layer about a foot thick located just under the topsoil. If you go deeper, the soil becomes too sandy. It's really great soil for growing things - and hardly any rocks - but not as good as the clay for making CEBs. You want the clayish soil to be fairly dry.

Next you break out the sand and Portland Cement to mix with the soil. Cement is about 5-8% by volume, the sand is added to help get the right consistency for the whole mix.

Then you put them all into the mixer according to the recipe. Once thoroughly mixed, the mixing bowl is tipped over and dumped out on the ground where it can be scooped into 5 gallon buckets.

The buckets are then carried to the hopper of the Green Machine, where they're dumped through a coarse screen into the brick-making area. The machine does the rest automatically, pressing out a brick in about 10 to 15 seconds and pushing it out onto the conveyor belt where they can be taken and stacked to cure. They cure best if they're damp, so they're sprayed down and covered with plastic. For now, they're just stacked on the ground. Once the foundation and first floor deck are finished, they'll go straight from the machine onto the wall where they'll cure. They become pretty hard with in two hours, but Wayne likes to give them a full week to really set up completely.

Compressed Earth Block Production Started!

Meet Wayne Nelson. He's the "guru" of compressed earth block (CEB) production with the Green Machine. He's a good friend of our architect. They have teamed together on other jobs using CEBs for international housing with the Habitat for Humanity. Wayne lives in Americus, Georgia, but came north to train a local crew in the art of CEB making. Normally Wayne would be on site the entire time , but has other commitments after June 6th, so needs to get the team started now while he's available. The crew is just stacking the bricks in a pile. They will be moved onto the wall of the house once the foundation and first floor deck are complete.