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The History of Concrete and Our House Foundation ?

The History of Concrete and Our House Foundation ?

The post below was sent as an issue of my newsletter, Ready for Rain.


Rocks, Sand, Lime, and Water

Living on an island is a constant reminder that almost everything here had to be brought to the island in some form and usually on a boat. The vast majority of the houses, for example, were made from materials from the mainland. Steel beams, lumber, and appliances all arrived here on ferries and barges. It’s kind of incredible.

Thankfully one of the heaviest and most used materials is made right on the island: concrete. And lately, we have seen our share of concrete trucks and pumps as the foundation of our house has finally taken shape. Starting the construction process, I knew very little about it and now, I think concrete is fascinating.

On the podcast 99% Invisible, a guest appeared recently, named Vance Beiser, who had written a book about one of the main ingredients in concrete: sand. The book is called The World in a Grain and he shared a few of its stories in the show.

Concrete goes back to Roman times, or perhaps before. People somehow figured out that heating limestone creates lime, which could be mixed with water to create cement that hardened like rock. When mixed with gravel and sand, it formed concrete. This discovery meant Romans could build structures like aqueducts and multistory buildings. Today, these are still the basic ingredients of concrete.

But then, the Roman Empire fell and concrete seemed to be forgotten. The invention was lost for the next 1,500 years. What brought it roaring back was the great San Francisco fire.

Ernest Ransome, in the mid-1800s, figured out that you could add rebar to concrete to create a very strong and fireproof building material. He built a few buildings around San Francisco with reinforced concrete, but the idea never caught on. Then, the city burned to the ground in 1851 and guess what was left standing? Ransome’s concrete buildings. From that point on, concrete became the building material of the future.

Here on Orcas Island, we have no shortage of gravel and I’ve heard that our concrete company has its own source of sand. What must come from the mainland is lime, which is ironic, as lime has played a significant role in the history of the San Juan Islands.

After the San Francisco fire sparked more demand for concrete, limestone was discovered in the San Juan Islands and local entrepreneurs went to work. Fortuitously, the limestone was often found near the shore, which made it easy to load the processed lime onto boats for shipment to the mainland.

Like today, the process of creating lime and cement is energy-intensive and involves heating limestone up to 2000(f). To do this, they built lime kilns fueled with wood that burned 24 hours a day. For a while, the San Juan Islands were the biggest producer of lime in the state.

A refurbished lime kiln. Photo: WA State Parks
A refurbished lime kiln. Photo: WA State Parks

But there was a problem. If lime comes into contact with water, it becomes highly combustible and can cause fires. And once lime combusts, it can’t be put out with water. Like a grease fire, it must be smothered. This meant every boat leaving the islands full of lime was taking a risk and some didn’t make the journey. It didn’t take long for mainland customers to find safer and more affordable sources of lime.

Today, for our house, concrete is an essential part of the foundation and one we’ve tried to minimize. Our original plan was to have an unfinished basement with concrete walls. Being on a slope meant that, in places, that wall was over 15 feet high. That design required a LOT of concrete.

The original plan: concrete walls
The original plan: concrete walls

When we redesigned the house to be more affordable, one of our goals was to reduce the concrete significantly and the idea of a basement was the first to go. Instead of concrete walls, we would support the house on steel posts. These posts would rest on concrete footings but require only a fraction of the amount. Thanks to the redesign, we cut our use of concrete by about half. So yay for that.

The new design - posts instead of concrete walls

With all the forms in place and inspected, we could finally pour concrete and watching it all happen felt like the house was finally taking shape. A giant truck arrived on the property that pumped concrete through a tube that a team maneuvered around the property to fill each form. The pump truck stayed in place as a succession of concrete trucks kept it full. Rocks, sand, water, and cement. 

pump truck

The work happened in two phases. First, the footings were poured to create the house’s foundation. This is the where concrete touches the ground.

house’s foundation

Then, more forms were applied to create the stem walls. These are the short walls and posts, built on top of the footings, that the house actually rests upon.

footings 1

footings 2

footings 3

footings 4

The day the team pried-away the wooden boxes to reveal perfectly formed concrete walls was like Christmas. The stem walls were all at exactly the same height. More than ever before, the house was out of the ground. I could stand on a concrete wall, look out at the view and experience it at 272 feet above sea level, the elevation at which we’ll live.

concrete walls 1

concrete walls 2

Walking around the property, I continued to marvel at the size of the concrete footings, which would soon be attached to steel posts and frames. This house isn’t going anywhere.

concrete walls

In the midst of all the big, heavy and messy work, I noticed a small detail. Kelly’s concrete team took the time to add little bevels to the edges of the footings. While 95% of the concrete will be buried, the top 5% will be visible and the bevels make them look more finished.

concrete walls 4

This is the kind of small detail that matters and makes me appreciate working with professionals. I didn’t ask for that feature or expect it. But now, that concrete is more beautiful to me than I expected.

We’re entering a phase of the project where craftsmanship and attention to detail will be more obvious and important. In my experience, the houses that look and feel the best have an undefinable quality about them. Sure, they may have a great layout and beautiful finishes. They may have a nice location. But the subtle quality that makes the difference comes down to working with builders who take pride in their work.

YouTube Highlight: Flying Over the Project

Flyover of the Project and Water View
Getting the House Out of the Ground ??‍♂️??‍♂️?

Getting the House Out of the Ground ??‍♂️??‍♂️?

The post below was sent as an issue of my newsletter, Ready for Rain.


Out of the Ground

In the parlance of contractors, home construction is completed in phases. The first, is “getting out of the ground”, which means laying the foundation. They say things like, “Once you get out the ground, it gets easier.” and “The project is more predictable once you get out of the ground.”

I suppose it makes sense. The ground is the big variable in construction; an uneven and unpredictable interface connecting the building to the property. And in this phase, stakes are high. The entire house depends on the placement of the foundation. It has to be right when the concrete is poured.

Like so many parts of the project, you have to trust the professionals to get it right and on this project, that was Kelly, the owner of the concrete company. The first time I saw him was on our construction site and it was immediately apparent that he had a unique sense of style.

It was summer and he was wearing a tank top and shorts with gold chains around his neck and wrist. On his feet were brand new, spotless sneakers. While this isn’t typical northwest attire, it’s really not construction site attire. But that’s Kelly. 

I chatted with him over a couple of days and grew to like him. He encouraged me to ask questions and be a part of the process. He said multiple times that he really liked the design of our house, in part, because it was simple. I suppose that’s relative. We set out to have a simple house, but the concrete work to make it happen seemed anything but. I took his word for it. Kelly has seen it all.

Having never been through the concrete phase of a house project, I didn’t know what to expect. My frame of reference was the Yurt, which was not a fine specimen when it came to quality construction. The deck was stable, but not very strong. It bounced and swayed just enough to notice when filled with visitors. I worried about its integrity. 

On a few occasions, I inspected the underside framing, just to be sure that braces remained connected. I saw no crumbling concrete or rotting wood. I deemed it as safe as a layperson could, especially knowing that its days were numbered.

Like nearly everything about the building, the Yurt’s connection to the rock was, shall we say, serviceable. The posts that supported the deck were small and connected to concrete footings attached to the rocky surface of the property. To me, it looked like the deck was supported by little concrete feet.

The Yurt's Little Feet
The Yurt’s Little Feet

While relatively young by northwest home standards, the Yurt was a relic of a bygone era when houses weren’t expected to stand up to earthquakes and strong winds. I doubt it was built with input from structural engineers or to adhere to strict regulations. Needless to say, things have changed and it all became very clear as our house got out of the ground. For us, nice little feet were out of the question.

The complicating factor was where we chose to place the house on the property. It sits on a small knob at the edge of a downhill slope made of rock. On paper, this is obviously the best location for maximizing the view. It’s as close as you can get to the water without building the entire house on a slope. 

Being on a knob, half the house will sit on the rock and half will be supported by posts and steel frames. What I didn’t understand in the planning phase was the incredible engineering and structure that would be required to make it work at that location. According to the regulations, the house must withstand 144mph winds and earthquakes that could cause it to tumble down the hill.

half the house

The people in charge of preventing these problems were structural engineers. They are like the doctors of the process and are responsible for ensuring the house is safe and strong. And like doctor’s orders, what they specify about the construction must be followed. They designed the all-important connections between the house and the ground.

Their designs all became very real when Kelly’s team started building the boxes, or “forms” that give the concrete shape and strength. These forms were wooden boxes, filled with rebar and eventually concrete, that creates the foundation for the house and the posts that support it.

Seeing the size of these boxes blew my mind. They were huge! I couldn’t help but think of the little feet on the Yurt which seemed like tic-tacs compared to these emerging behemoths.

The deck piers
The deck piers
The deck piers 1
Foundation for a steel "moment" frame
Foundation for a steel “moment” frame

At first, I was incredulous. It almost seemed like there had been a mixup. The forms, from my perspective, seemed like they were meant for a much bigger house. “These are for our deck?” I thought. Surely not.

Later that day, I looked at the plans for the property and tried to imagine a different scenario. If we had decided to pull the house back away from the slope by twenty feet, most of the house would be on more level ground. We could have avoided a lot of excavation and rock work. The engineering could have been simpler and more affordable. 

But we didn’t do that. We weren’t thinking about engineering or excavation when we planned the house’s location. Along with John, our architect, we were trying to execute a dream. To us, this specific location is special and deserving of a house that’s designed to take advantage of it. Anything else would be a compromise we’d likely regret.  

our architect

Of course, it’s easy to justify past decisions when your property is covered in rebar and forms. We were literally locked-in.

rebar and forms

There is, now, no room for revision or second-guessing and from that fact, I take comfort. I take comfort in having those decisions behind us. And I also take comfort in knowing that this house, our forever house, is being built to last in spot we chose.

Years from now, once the last nails have been driven and the concrete boxes are hidden underground, we’ll have confidence that we feel every day. When we walk onto the deck, there will be no swaying or bouncing. There will be few worries about wind or earthquakes. We’ll know the house will outlast us because we saw the rebar and concrete it took to make it work.

More On YouTube

The video below is a fly over of the project. More here.

Drone Footage of the House’s Foundation