Burial, Phase 1.

Our earth-sheltered house design uses an “umbrella” concept to retain the heat and keep things dry. This post covers the first phase, the dirt under the umbrella. Still, it was a big step.

The Video

The Gallery

Often the story is best told with pictures anyway…

This is actually an action shot with the dozer pushing dirt over that edge

Here is the section of wall that fell out. I forgot I had this pic when I did the previous video. I guess I’ll go add it to that section of the blog.

In this scene, Dick couldn’t see where he was dumping so Steve was his eyes… Communication is key.

The shovels were left there to keep the insulation pushed against the wall until the spray glue dried…

Do you think he noticed the bulldozer or is it still a mystery how the line was cut?

I thought the repair was pretty interesting.

A shovel to remind Marty the depth and location of the power lines.

We had layers of insulation behind the boulders, but there was also insulation up against the playroom, etc. We used a lot of insulation.

Michael setting up the camera.

Dick Roe, an original Roe Brother. He seems to operate the excavator like it was an extension of his body. He has clearly spent enough hours in there that it is all muscle memory at this point.

I don’t recall why I was laughing…

Sherri surveying the destruction

At the end of the first day…

They switched fromt he small bucket to the big (wide) bucket, depending on what work they were doing. Like changing the bit in your screw driver.

Lifting the first vertical stone…

Sliding in the key stone

Steve and I put a lot of thought into the placement of each rock so they would interlock nicely. It is hard to see from these pics, but the vertical ones are tilted back and tucked behind the flat ones. They are also tucked behind the concrete wall. I later came back and used mortar betwen all the rocks and drilled and pegged them together with #5 rebar, etc. It has been about a year and I don’t see any cracks in any of the mortar yet.

The excavator is sitting on a ramp made by the bulldozer so it could reach high enough to place the dirt.

This is the view out our playroom window.

Steve (working for Roe Brothers as the man on the ground) was very helpful and fun to be around.

Shovels are for fine tuning the dirt placement

We had them dump dirt in thru the skylights so we wouldn’t have to take it in with wheelbarrows. We needed it for making stucco and to bring the floor height up from the footing depth to 6 inches below final floor depth.

Color is funny in this pic, but this is the dirt spilling out from between the dormers on the south side. Like sand thru an hour glass.

Pushing dirt up the north side of the bedrooms

After the dozer tore up the ground, I went and did some rock picking

How it all looks from half way down the hill

The insulation was placed and waiting to get to work on the umbrella.

End of day two.

End of the 2nd day and the guys are packing up to leave

The center section of the house still has no roof

This hill is pretty steep here, but hopefully will be improved with the other two layers

Just a look at the terrain at the end of the day

Michael at the end going to pick up the camera after the last scene.

Building a CMU retaining wall around the office apse

In order to bury the office apse at the front of our earth sheltered home, I needed to build a retaining wall with a window in it. For this corner of the build, I decided to use CMU’s, Concrete Masonry Units, AKA concrete blocks. We also had to insulate the apse structure.

I may come back and add some detail here. For now, I’ll just post the video and gallery of pics to tell the story.

The Video

The Gallery

Here are some pics to help tell the story.

Sherri getting a selfie

Sherri and I decided to roughly imitate the “American Gothic” paining.

Couldn’t hold the straight face

And back to work…

Camera caught a block drop in mid air and I thought it looked worth keeping.

Michael’s turn to get a selfie

We put 4 inches of XPS between the apse and the retaining wall. This first 4 feet were easy because of the simple curvature.

My mother faithfully working on the insulation dome.

Here Michael is cranking away on the dome. You know this process is decent when an 11 year old kid can crank it out.

Posing with my subway vinyl. In theory, you are only supposed to use these with the image downward, but I couldn’t resist.

We glued the vinyls together with HH-66 vinyl cement. It basically melts them together with a chemical bond.

Perspective…

Here you can see that the insulation layer completely separates the inner and outer walls. The rebar and lath were covered in concrete, ferro-cement style.

It was getting dark by the time I got that concrete up on the eyebrow.

The insulation mosaic was rough looking, but functional.

Go pro caught this fun one as I drove by… I guess I was looking at the camera to avoid driving over the tripod.

David pondering life from his new thinking spot.

Gunite for the Tower

After waiting more than 2 months for our shotcrete crew to come out, we managed to find a new gunite crew in the area. S.A.M. Pools came out and did a great job. We can talk more about the details in the blog, but first, the Video.

The Video

The Wait

Waiting for contractors is just a normal part of building. It just gets worse when you are an independent builder because the contractors all have more regular clients that are more important to their long-term success than your “filler” job.

We couldn’t get our shotcrete guys to come out and the summer was fading away, so we began the search for a replacement. Gunite and shotcrete crews don’t seem to put any effort into direct advertising. Most don’t even bother listing their phone number anywhere, never mind having a website. Instead, they work for landscaping and pool companies.

So I began to call those sorts of customer-facing companies. However, those companies do not want their subcontractors getting other work because it could lead to increased prices and reduced availability. I could see that they had done shotcrete work based on pics on their website, but when I would call, they would only tell me that they subcontracted on an as-needed basis and would be happy to manage our job for us.

In a few cases, I managed to find the names of some of these subcontractors and mostly found that their motivations were similarly frustrating. Keeping the landscaping and pool companies happy was their primary motivation and my side job was just a distraction. I actually had a few of these companies out to look at my site and give me a quote. But then they were all solidly booked and said they would keep me in mind if a bigger job every canceled on them and they suddenly need work. In other words, I could be lucky enough to be their back-up plan, but would get very little notice.

And then I somehow got the name of S.A.M. Pools. I can’t even remember the chain. I have several contractor friends and I think one of them gave me the name of a guy who has quit the business, but gave me the name of another guy who knew Scott at S.A.M. Pools. When I had started my search a couple of years before, they were a pool plastering company, and it was only in the past year that they had bought a gunite rig. Even now, a year after doing my job, their website (much better than most) still doesn’t mention a single word about gunite.

So, when I called Scott (the “S” in S.A.M. Pools), he came out right away and gave me a quote. We considered it, did some math, etc. and found it was on the high end of the range of what we had paid for shotcrete, but at least it was in the range (our Shotcrete prices had varied wildly). The quote also said he could start the following week. I texted him over the weekend to say we accepted the quote. I just went back to find my exact words… After saying I accepted, I said:

He immediately phoned me, seriously insulted because he had already told me that he would be available and did I not think that within a week of giving the quote was soon enough! Of course, I apologized for assuming that he was like the others who had given me quotes without any plans to actually show up. We coordinated based on weather and time required to get the supplies delivered and booked a date for gunite on Friday that week.

This was after about 11 weeks of waiting for the previous shotcrete crew, so I was nervous all week that they would finally become available and I would need to decide to decline one or the other. I needn’t have worried. After the gunite was up, I texted the shotcrete crew to tell them they didn’t need to worry about doing that tower any more because it was done. They wished me good luck.

Differences between Gunite and Shotcrete

Gunite and Shotcrete are more similar than different, but lets talk about the differences. I have now had two crews work on my site, the first was shotcrete and the second was gunite. Primarily, you should care about the fundamental differences between the methods. However,there were also significant differences between the crews that I personally worked with. I’ll try to keep those separated. The crew stuff belongs here in the post about my own personal experience. The fundamental differences in the method belongs as one of the technical posts.

The Crew

Let me start by saying that I appreciate any crew willing to come out and help on my project. This goes double for something as physically demanding as shotcrete. In full disclosure, I should note that I have since had a falling out with the previous shotcrete boss because I wouldn’t remove the Youtube videos after many negative comments came in (the internet is such a friendly place), so I won’t mention any names here and will try to be as fair as possible (actually, I am being very generous).

The shotcrete costs were wildly erratic and often doubled the quote. The unpredictability was very stressful and always ended up much more expensive than I budgeted for. In contrast, the gunite crew gave me a quote and it was exactly that price at the end.

Communication between jobs and during the jobs was so much better with the Gunite crew. Messages were promptly returned with phone calls and rapid resolution, etc. The only thing that wasn’t rapid was sending us the bill. Meanwhile, the shotcrete boss left me with hundreds of ranting text messages. Some optimistic or fact-based, others swearing at me and calling me an idiot, and then followed by more positive ones and then almost all very negative after we switched to the gunite crew.

The quality of the work was the biggest difference. The gunite crew used measuring tapes, cleaned up their messes, and produced smooth flat plumb walls. In contrast, I never saw the shotcrete crew measure anything or use a single level, they left (literally) tons of mess for us to clean up and the walls were very rough despite my many pleas to have them smooth things out. I don’t know what portion of the low quality was due to apathy vs skill level, but, in theory, a shotcrete crew could get the work just as nice as the gunite crew if they had the skill and wanted to.

The Method

Differences such as the compressive strength or durability of the concrete (its all about the mix), the slump of the concrete, the pace of the work and even the weight of the hose are technical differences compared on this technical page.

The Galery

And here are some pics…

They dropped off supplies and equipment the day before. This got me excited 😉

This part of the gunite pump works like a geneva drive from a film projector, except it moves pockets of mix instead of frames of film.

Bert was great with the Skid Steer, running it around at high speed.

Joe keeping the rig going

Walls were done one level at a time.

planning the ladders for the next section of tower

Back wall of the kitchn

Behind the stairs after the second pass

Mezzanine after the second pass

second phase on the tower

Cleaning up the tower after the second pass

Master Bedroom eyebrow after its first pass

Eyebrows after a pass or two

Eyebrows after the second pass

Mezzanine during the 4th pass

Michael picking up the camera and taking a quick pose

They got the office done before the weekend. I kept it wet to improve the cure.

Office completed, you can see all the rebar chairs on the inside

Behind the gap between the two eyebrows

Almost done the eyebrows

The final edge of the tower

All done

Tower pass thru

Looking up in the finished tower

The wide angle camel unravels this tower

Carlos after finishing up

A look down into the tower. In the original plan, all the concrete ribs were supposed to be a few inches further out so the tower would have had a smooth inside. Oh well, mistakes were made and the house is a little smaller now 😉 All due to rushing on the day the crane was there. I’ll work some sort of book shelf into it and it should look fine.

Carlos enjoying the view after he was done

They were able to clean up this nice ledge so I can set my quad deck slabs up here easily.

You can see the wire that I tied at the right height. Then I asked the crew to trim off the concrete along the wire.

Jimmy after shoveling out this big pile of rebound and trimmings

Taking away the rebound with the skid steer

Cleaning up with the skid steer

Bert dumped the rebound on my concrete waste pile on the back side of the garage

After they were done, the rain picked up, which was just perfect for curing the concrete

A few weeks later, I began to strip off the forms

A few weeks later I started to tear off the forms.

Stuccoing the skylight curbs

While we were waiting for the shotcrete crew, we continued on some side jobs. One of which was insulating the skylight curbs and protecting them with stucco. Detail on our mix recipe, etc. later, but first, the video.

The Video

The Mix

Here, we used the scratch stucco recipe of

5 buckets (25 gallons) of sand
94 lbs (1 bag) of portland cement
17 lbs (1/3rd bag) of hydrated lime

We mixed this all dry and then used buckets of the mix, mixed with water (about 20 cups) using a drill mixer. After applying the stucco (it naturally forms a layer about 3/8ths of an inch thick), we used a “scratch” tool to give it texture so the second layer would grip it well. Then we left it for a few weeks to cure and watered it often to increase the strength during the cure period.

The recipe for the brown coat was very similar, except with 10% more sand and lime to weaken it a little bit. You want the brown coat weaker so that if it tries to shrink as it cures, it will crack instead of cracking the scratch coat off the wall.

Before applying the brown coat, it is a good idea to wet down the wall. Otherwise the moisture from the fresh stucco is sucked into the scratch coat and it is difficult to work with.

After applying the brown coat, we continued to water it for another couple weeks, again to improve the cure and the strength.

Improved mix

As I mention in the video, along with our improving stucco skills, we also experimented with the mix and found that adding a quart of thinset after mixing in the water really improved the workability of the stucco. It also improved the stickiness (important for ceilings) and gave it some waterproof characteristics also.

The Gallery

Again, sometimes the easiest way to tell a story is as captions on pictures.

The skylight concrete would have leaked a lot of heat. So we needed to wrap them in insulation. But first we needed some wood to screw the insulation too… Necessity is the mother of invention.

This side of the skylight needed more insulation because it included some vertical ducts. I decided I would need to extend the electrical box a little. This was not enough.

In one of the first attempts, it became clear that the electrical would be too recessed.

So, I ended up using a bunch of outdoor box extenders… If it looks stupid, but it works, its not stupid?

Another view of my stacked electrical.

The outlet after we got the stucco around it

Eventually, we covered the wood tops of these with copper…

We often work until sunset around here…

Brown Coat Stucco

Brown coat stucco

Prepping the eyebrows for Shotcrete

While prepping the tower and mezzanine, we also worked on the bedroom eyebrows. It was just too big for one video. More on what “bedroom eyebrows” are after the video.

The Video

Bedroom Eyebrows

Bedroom eyebrows are not some sort of double entendre that only earth sheltered home builders get after a long hard day. They are simply the structures we used to keep dirt off the windows while still having a hilly appearance. You see them in Peter Vetsch earth shelters all the time. However, I suspect (from construction photos) that Peter’s eyebrows are big heat radiators that drastically reduce the thermal efficiency of his buildings. I wanted to avoid that problem, so I needed mine to be thermally isolated from the actual home.

I did this by separating the shotcrete into two phases. After completing the bedroom shotcrete and waterproofing it, I added a saddle of 4 inch thick XPS Foamular 250… This is the kind that can handle 25 psi of pressure and is intended for burial. Above the XPS, I build another rebar framework and put shotcrete over that. Or at least, that is what I wanted to do.

In more practical terms, I used tapcon screws to mount treaded wood 2x4s directly to the bedroom shotcrete. Then I drilled holes in the 2x4s to hold the rebar framework… So there is a little edge all the way around where I sacrificed long-term insulation for a more buildable structure. I have since considered other ways I could have done this and may do it differently if I ever had to do it again, but I don’t think the performance will be too bad. Certainly still better than a more traditional house.