Building the Largest Underground and Off-The-Grid Farm on the Planet - Part 10

Welcome back for Part 10!

The homeowner scheduled the shotcrete pump company and we finalized the concrete mix with the concrete company that we chose to supply us. The mix for the shotcrete on the earth shelter domes was unique in that it set up in under an hour and the concrete company did not want to supply us with the concrete if we weren’t comfortable with the timing. The concrete company was located about twenty minutes away and that only left forty minutes to use all of the concrete on the truck before the concrete would begin to harden. Luckily I had worked extensively with this concrete company on other projects so I was able to talk them into trusting us that we could pull this off. Secretly, I had no idea if we could do it or not, but I figured that I would never know unless we tried it. Little did I know, the dispatcher at another plant an hour or so away told the dispatcher of this plant that we were tough enough to pull it off so they approved our concrete loads.

Everything was scheduled to begin early on Monday morning and our lift machine was delivered over the weekend. When we left that previous Friday, everything was dry, the clay around the domes was hard and the ground looked even enough to drive a lift around every inch of the domes. Part of our crew arrived on Sunday because we wanted to get an early start on that Monday. Like others in the construction business, I was glued to the weather on my phone over the weekend because there was talk about rain on that Sunday, we didn’t hear anything about rain until we left that previous Friday.

     (Flooding along the barn dome. We worked for several hours to pump the water off of the site.)

When we arrived to the jobsite on Sunday afternoon, we had hoped to unload a few of the tools we needed then go and catch a movie in town to relax for the grueling week ahead. The rain was pouring down hard as we drove up close to the domes and that is when we saw the standing water everywhere from the torrential downpours. Instead of going to the movies, we went and rented water pumps to try to get the areas around the domes dry before the morning. Thankfully the rain stopped and we were able to pump all of the standing water out from the domes so that the ground would have a better chance of drying out by the morning. I was worried that the lift would get stuck or worst yet, tip over if we had to drive through the mud. It was dark by the time we finished pumping the water and all I could think about was going to bed and trying to get some sleep before the most physically demanding week of my life.

        (Flooding from a heavy storm. We worked several hours to pump all of the water off the site.)

The alarm went off early and everyone met in the kitchen of the funeral home turned bunkhouse for breakfast. No one knew what was about to happen, but the crew I had assembled was used to the unknown and also very good at figuring things out as they happened. The shotcrete pump owner and his son stayed with us in the funeral home, so we could all get to know each other before we got to the project. I really like the two guys, they were funny and appeared to be hard workers like we were. They mentioned that shotcreteing was a lot of work and normally one guy would only last fifteen minutes manning the hose. I thought in my mind that we would run the shotcreteing  hose like a hockey team changes its lines up. We would switch guys every ten minutes to keep everyone fresh. It was a great plan on paper, but it didn’t work as I had hoped as you will read about later.

We were on site before sun up on the first morning of the ‘spray pour’ as it is called in the documentary of this project named Sheltered: Underground and Off-The-Grid. I remember wondering where Crazy Joe was as I heard the first concrete truck coming into the long winding drive way. The shotcrete pump machine was running and we were assembled near the front of the small dome. I was concerned that Crazy Joe may not show up and that would mess up my plans of rotating our time on the shotcrete hose. Just then, Crazy Joe comes around the corner in the driveway and passes the concrete truck in the long grass along the driveway.

                     (The special mix concrete being dumped into the shotcrete pump machine.)

I was relieved that he showed up and I just smiled when he ran up and apologized for over sleeping. He disappeared into the small dome just as we were instructing the concrete truck where to pull up to and start dumping the load of concrete that was forty minutes into its one hour set up time. As I put my hard hat on, I looked up and Crazy Joe came up to me with blood running down his face. He had hit his face on one of the wooden braces inside of the small dome connector tunnel as he was running to get a tarp on the floor. The blood he wiped off of his face was quickly replaced with a fresh stream and I took a closer look to see if he was hurt or injured. One is worse than the other and it was apparent to me by the look in his eye, that a cut on his nose was not going to stop him from spraying shotcrete, so I yelled, “Clean that up, let’s get ready to rock!” He yelled back, “Aight!”

           (The crew during the first minute of shotcreting. It was a tough ride but we figured it out!)

The noise on the jobsite from all of the diesel engines roaring was deafening. I could not hear anything and found that the best way to communicate was to point or have someone knock me on the hard hat when they needed to get my attention. Like a child with a new toy, I grabbed the concrete hose which weighed forty pounds per foot with concrete in it, through up over my shoulder and stepped into the area between the little dome and the greenhouse dome. I looked at Crazy Joe and he looked back at me with the grin that let me know that we were going to be in for the ride of our lives! The first shot of concrete came out of the hose with a lot of pressure and a short burst. The force and power of the spraying concrete caught me off guard and my 240 pound six foot three inch frame was pushed backwards like a palm tree in a tropical storm. I righted myself and dug in for the next short burst, that time I was ready for the power of the hose and the concrete sprayed on and stuck to the burlap. We were thirty seconds into the ‘spray pour’ and I was already wondering how we were going to shotcrete the entire complex with just a hand full of guys..

Stay tuned for Part 11 and ride along as the team digs in to shotcrete all of the domes..the team fought through injuries and didn't stop until the Largest Underground and Off-The-Grid Farm on the Planet was shotcreted!

 (One of our team members getting washed off after the burlap blew out and he was covered in concrete. His head was burned from the lime in the concrete.)

Building the Largest Underground and Off the Grid Farm on the Planet Part 9

Building the Largest Underground and Off-The-Grid Farm on the Planet—Part 9

Welcome back for Part 9!

There are many things that have to be figured out ahead of time if you work with concrete. Once concrete sets up, putting holes in the concrete or adjusting concrete is very difficult and time consuming. One of the many things that had to be determined before we could shotcrete the earth shelter domes was ventilation and where those ventilation tubes would come out of each of the five earth shelter domes and various connector tunnels. I decided that we would run the ventilation for bathrooms, cooking vents, dryer vents, and air exchanger vents out the sides of the domes. Luckily the founder of the earth shelter dome company was watching our weekly videos on this project and noticed the episode where we were running the tubes out the sides of the domes. He emailed me and told me that all ventilation has to come out the front wall or the top of the domes near the ridge of the dome structure. He told me that the way we had the ventilation pipes was not right and that as the earth settled around the domes, anything coming straight out of the sides of the domes would be broken off from the pressure of the settling earth. Because of this email, we delayed shotcreting so that we could reposition our ventilation ports to the top of the domes.

I studied a great deal about earth tubes and passive ventilation for this project because the homeowner and I felt that non mechanical ventilation would be a good fit for this project. The more I studied about the earth tube ventilation idea, the more I found that there was a very distinct line right down the center of the people who believed the earth tubes worked and those who didn’t think that the earth tubes would work. Briefly, earth tubes are a passive ventilation system which includes pipes of a specific diameter run underground for certain distances with the idea that the ground would pre-condition the air as it comes into a building. I questioned if this system would remove the high humidity that Michigan gets in the summer time, and I wondered how introducing humid air into a structure which is constantly battling humidity would work. I created what I thought was a good solution and we will cover that in a future installment of this series. We will also discuss the low voltage Panasonic Whisper Green bathroom fans which we used on the project in a future installment of this series.

We spent the time to rerun the ventilation pipes in each of the five domes. We made the pipes coming out of the top of the domes just long enough to shotcrete around without the pipes hindering our need to walk around on top of the domes to shotcrete. The plan was to connect the pipes during the backfilling of the domes which would occur several months from the time the domes were shotcreted.

Around this time, our friend Pam from out west emailed me to let me know that the burlap on her earth shelter domes had been exposed to the sun for less time than what the burlap material on our project had been exposed to the sun and they found that her burlap was deteriorating from the exposure to the sun. The next day after that email, I went to random spots on each of the five earth shelter domes on our project and checked for deterioration of the burlap. In some spots, the burlap was very weak and in the areas that were covered with the tarps all winter, the burlap was in great shape still. I emailed Pam back and asked her how they dealt with the bad areas of the burlap when they shotcreted her domes and her response was that they used cardboard as a backer in the areas that had deteriorated burlap. The burlap is what stopped the shotcrete from passing through the rebar and wire mesh. She offered another piece of advice and that was that the spray from the shotcrete left an incredible mess all over her concrete floors and the clean up was very difficult. Pam recommended moving tarps around as we sprayed the shotcrete, which we did and I still thank her til this day for that piece of advice.

The value of videoing our project and putting it online was paying off. If I didn’t receive the emails I mentioned above, the shotcreting of the domes and the cleanup following the shotcreting would have been a real game changer on the project. Filming the project and putting up a video every week on Vimeo allowed many people to follow along and those people often caught something that I missed or suggested a course change as we neared pivotal points on the project.

With the emails and my gut instinct, I created a list of duties for each person who would be working on our crew during shotcreting. I figured that we could shotcrete the domes in six days and that would allow us to work normal length days that would not only keep our crew fresh but also avoid any overtime charges from the pump company or the concrete company. Skeptics of this system of shotcreting for an underground structure often mention the fact that ‘cold joints’ were the biggest issue in multi-day concrete pours. Cold joints are basically the point where concrete meets when poured at separate times, for instance, pouring concrete on a Monday and then finishing the pouring of more concrete the following day.

The cold joint concern came to me in an email from some random person who was watching the weekly videos. This cold joint concern got me thinking, so I contacted the founder of the earth shelter dome company and told him what I was thinking. My idea was to stop the shotcreting each day in non impacting areas, such as the center of connector tunnels and not stopping on the sides or parts of the domes. He agreed that the best way to avoid cold joint problems was to stop and start the concrete pours in the areas with the less force against them and/or in areas that didn’t create a breach in strength in any one of the domes. Can you imagine what would have happened if I didn’t get those emails? Thank you everyone who was back seat building while watching the videos, you all helped save me a lot of grief!

Now that we had a very clear path of what we needed to do to successfully shotcrete the largest underground and off the grid farm on the planet, the next issue was getting Mother Nature to cooperate. The weather was warming up and we finally were able to schedule the pump truck and the concrete and get our game faces on for a week of shotcreting.

Stay tuned for Part 10 and ride along as the small crew sprays nearly 900,000 pounds of concrete in a week to create the outer shell of the largest underground and off-the-grid farm ever built!