5. Grading the House Pad

Once we got the building permit, grading could begin. The grading company cut the hill with a backhoe, and formed the pad using a bulldozer and water truck. Because we are on a slope, they cut into the hill on the high side, and added dirt to the low side, but they also did what is called “over ex”.  Over ex is accomplished by digging deep down into the original hill and, mixing the dirt with water, re-compact it so that the finished pad is actually wedged into the hill underground. All the dirt they moved is mixed with water and re-compacted. It ends up being extremely hard and has to pass a hardness test to get signed off by the County. It was like the pad was one big adobe block!

Cutting the hill

Cutting the hill

Dozer and water truck

Dozer and water truck

Testing for hardness

Testing for hardness

Finished pad with reserved dirt for making adobe blocks

Finished pad with reserved dirt for making adobe blocks

4. Planning the House

Architect and Engineer

 

When we went to our local LA County Building and Safety office in Lancaster to apply for a building permit for an adobe house they said, no way! They directed us to the Research Unit in Alhambra where we made an appointment. In the meantime we had been to Adobe Building School in New Mexico and there we learned about two essential people we would need to build our house.

 

The first was Fred Webster, civil engineer and seismic expert. Fred had decades of experience working on historic California adobes and was one of the very few engineers who understood the structural nature of adobe blocks and walls. Other engineers that we approached wanted to build a house of post and beams with adobe infill, but no, adobe has its own inherent strength and can serve on its own as the principal structural component.

 

The second was Rob Mehl of RPM Architects, an expert in alternative building materials. We visited his office and the Sanford Winery in Santa Ynez that he designed, seven huge beautiful adobe buildings.

 

Fred flew down from his home in Menlo Park and the three of us, Fred, Bruce and I, went to our meeting in Alhambra. As we sat across the table from three County building officers, they said the problem was “there’s no code for adobe.” Fred, who had been retrofitting old adobes for the past thirty years, reached for their code book on their shelf and opened to the page where the necessary code appeared in the masonry section.  The County guys, chagrined, said well okay, we won’t say no, yet – go ahead and turn in your plans and we’ll have a look. Without the team of Rob Mehl, architect, and Fred Webster, engineer, this beautiful adobe home never would have happened.

 

Rob and Fred drew up their separate plans, we submitted them in person, and we got the building permit – the first adobe building in LA County in forty years! And I doubt there has been one since, but if you are excited about building with adobe, go for it –it can be done!

 

Sadly, we recently heard of the passing of Fred Webster, engineer extraordinaire. Speakers at his memorial service recounted his brilliance, his outside-the-box thinking, and his ability to solve complex engineering problems. He was paramount in the specialized world of adobe engineering.

Architect, Rob Mehl, left, and Bruce, visiting the Sanford Winery in Santa Ynez.

Architect, Rob Mehl, left, and Bruce, visiting the Sanford Winery in Santa Ynez.

The inimitable Fred Webster, engineer extraordinaire

The inimitable Fred Webster, engineer extraordinaire

3. Going to Adobe School

 

Bruce and I went to Southwest Solar Adobe School in Bosque, New Mexico, where Joe Tibbets taught us how to make adobe bricks and how to build walls. Joe is a master of earth building, both bricks and rammed earth. He’s a true believer and an excellent teacher, and published the excellent magazine, Adobe Builder.

 We arrived at the adobe building school with a 5-gallon bucket of soil from our hillside from which Joe took a sample, shook it up in a jar of water, and let it settle out. As he carefully studied the layers that formed in the jar, he pronounced our soil a perfect natural mix of clay and sharp sand. The only other ingredient we would need is asphalt emulsion to make “stabilized adobe,” adobe that does not melt in the rain. The liquid asphalt does not add strength, it coats the clay particles so they do not melt.

 And we did not use straw. Everyone thinks adobe blocks need straw because that is how Spaniards made adobe in California, but in fact, straw is only necessary when the clay content is too high; the pieces of straw make voids that allow the clay to expand and contract without cracking the brick. If you have the optimum mix of clay, silt, sand, and aggregate (as we did by pure chance!) you do not need straw.

 After four days of intensive workshops, we left New Mexico convinced we could build our own adobe home.

Adobe Builder magazine.jpg

2. Drilling for Water

Drilling for water on a hillside is not the same as drilling for water in the flats where there is a known water table. There you know before you drill how deep you have to go to reach water. Where we live in Juniper Hills, drilling for water is risky business because the underground water here runs in “streams” through the different layers of rock, sand, and clay. We have one neighbor who drilled five dry holes (at $10k a pop)!  So what us-here-country-folk do is hire a water witcher.

Now I know that sounds very woo-woo to city folk, but believe me, in the search for water you take the advice of the locals. We hired three witchers and had one of them come back a second time. On his second visit, he chose a spot that one of the others had chosen (two were off the property!) and that’s where we drilled.

The driller drilled a six-inch hole, hit a little water at 100 feet, more at 300 feet, and kept on going to 400 feet to make a reservoir of 100 feet of standing water in the hole. To complete the well, they drilled the original six-inch hole out to a ten-inch hole and then put down a six-inch casing, a perforated pvc pipe that is surrounded by gravel, allowing whatever water is flowing by to enter the pipe and fill the reservoir. They lowered a pump into the casing with sensors so that the pump shuts off when the water gets too low and comes back on when the water level goes up.

The day we hit water, we were getting seven gallons a minute which is plenty because it goes into a 5,000-gallon holding tank and later into a pressure tank to provide pressure for the house.  We think we may have hit a pocket of water that day because eventually our well ended up producing only about a half gallon per minute, which it turns out is barely enough for our household uses and to water a very few plants. We have almost no landscaping, relying on native vegetation to create the beautiful environment we live in.

With the well in place and our basic need for water having been met, we could turn our attention to planning the house.

The drilling rig forces mud down through the stem to the drill bit which lubricates the bit and keeps it cool, and as it drills, the mud is forced up and out of the hole carrying with it the cuttings. What you see here is the mud carrying the cuttings flowing up and out from the bottom of the hole.

The drilling rig forces mud down through the stem to the drill bit which lubricates the bit and keeps it cool, and as it drills, the mud is forced up and out of the hole carrying with it the cuttings. What you see here is the mud carrying the cuttings flowing up and out from the bottom of the hole.

We are moving the 5,000-gallon tank to a new location. By the time I took this picture, we'd had the tank a few months and I had gone Brice Marden on it!

We are moving the 5,000-gallon tank to a new location. By the time I took this picture, we'd had the tank a few months and I had gone Brice Marden on it!

Bruce used his cherished Bobcat to dig a trench to lay the pipe to carry the water from the well to the 5,000-gallon holding tank.

Bruce used his cherished Bobcat to dig a trench to lay the pipe to carry the water from the well to the 5,000-gallon holding tank.

1. Overview

My husband, Bruce, and I built our adobe house with just us and a small crew, and this blog will cover most of the details for anyone interested and anyone who may be considering doing it themselves. This picture was taken after we were well into it...you can see the stacks of adobe blocks which we made on site, and the completed house foundation.

It all started when our friends came back from a four-day workshop in New Mexico, and we were inspired to take the same workshop. That was it! By the end of the workshop we felt ready to give it a try. At least my husband was. I kept wondering if we shouldn't just buy the adobe blocks which were readily available from a manufacturer in Modesto. But Bruce, being the spiritual guy that he is, was dedicated to the idea of making the house from the dirt hillside. Of course he was absolutely right, which he sometimes is.

We purchased ten acres of hillside in Juniper Hills on the north side of the San Gabriel Mountains overlooking the Mojave Desert, just above Littlerock and Pearblossom which are on Hwy 138. We had lived in Juniper Hills thirty years previously when our boys were growing up, and it's a perfect location for combining a wild area with access to a large metropolitan area - Los Angeles - necessary for me as an exhibiting artist. Being a rural area, Juniper Hills does not offer city services such as water and sewer, so first things first, we drilled for water. I will talk about that experience in the next blog.

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