Construction Technique

Footer and start of foundation wall.
Footer and start of foundation wall. The top of the footer is just below the existing grade.

Concrete construction is not the norm for homes in the US but it is common place in commercial settings and most of the rest of the world. We build homes with wood because it’s what we have. It’s cheap and we know how to use it. Concrete in Mexico and South America is like wood in the US. It’s cheapest and all the builders know how to use it. Concrete block is durable and impervious to bugs but earthquakes can cause widespread tragedy since block comes down more easily in a tremor.

The typical home here is a post and beam style structure. The shape of the house is made with posts and beams of reinforced concrete. Cement block fill in the gaps. The block and reinforced concrete parts go up side by side. The block walls act as half the form for the posts. A word about words: I’m a civil engineer and civil engineers call posts columns. I once made the mistake of calling a column a post in my structures class. I was nearly laughed to the curb. Despite that I graduated and was offered a post-graduate slot studying structures. I declined. But post and beam is the style of construction and I work with a guy that builds wood homes and it’s easier to type post than column. So I have regressed back to my earlier usage.

Since our lot is sloped and the existing structures are at its peak we are building this site up to match the higher level of the existing bodega/rumpus room. That means our foundation is from four to five feet high and we have to add a lot of fill. We’ve reached a bottleneck in our construction. Fill is highly sought after and expensive. It’s been two days of waiting and it finally arrived today. Rather it started arriving today. It’s 2:48 PM and we have received only 3 of the estimated 8 loads we need. That’s about 40 yards of dirt. Our crew is staying busy building rebar forms for the beams to hold up the ceiling. Other than that we’re moving right along.

Any questions?

Filling the foundation blocks with concrete.
Filling the foundation blocks with concrete. The foundation comes up about 4′ above the existing grade. This is to make it level with the upper side of our lot and keep hurricane waters out of the house. You can see the post waiting to be formed on two sides with wood while two sides are block.
Forms for the cadena or chain. It is a beam that ties the foundation together.
Forms for the cadena or chain. It is a beam that ties the foundation together.
The hole and the foundation.
The hole and the foundation. Long view of the beam or cadena that tops the foundation.
Foundation and some wall. Rebar will be poured reinforced concrete columns.
Foundation and some wall. Rebar will be poured reinforced concrete columns. You can see rebar bent at 90 degrees from the foundation wall into the area where the slab will be located. That rebar will tie the slab to the foundation. The slab will be reinforced with wire mesh.
Filling the hole.
Filling the hole. The back wall shows the wooden forms in place around the posts.
Fill dirt
Fill dirt
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Walking and thinking and looking

Bridge in Point Reyes National Seashore.
Bridge in Point Reyes National Seashore. The 12′, 9′ are depicted on the explanatory sign below.

Laura and I have been walking the same loop every morning.  Some days we walk clockwise and other days we walk counterclockwise. Today we were late. It was day seven of our 3.6 mile loop through oak savanna and vineyards. I was tired. The boys were going, too, and they are louder and faster. I let them go ahead and slept a few more minutes and then Laura and I went without them at 10:00 instead of 8:00. Was I tired or avoiding the men? Probably both.

Each day our vision grows keener. We see more birds and can pick out the different ones more easily. Yesterday I discovered a new species for me, the California thrasher. I love a thrasher. They carry big bills and aren’t afraid to use them. Today I spotted a gaudy Townsends warbler in a mixed flock of mostly chestnut backed chickadees, titmice, and dark eyed juncos. The Townsends was a bird I’d seen once before in Montana and the chickadees turned out to be a new bird. The chestnut backed variety has a limited range and where we are now is one of the places it does not overlap with the black capped chickadee so score a new bird while completely unawares.

The boys are hard at work turning this spread into Barry and Laura’s home. I am unemployed. Barry has supplanted me as walking companion and assistant carpenter. He does not play Bridge. Yet. Today the boys told me they are going to pour a concrete slab. I responded with, “Did you know that concrete production accounts for 5% of all global CO2 emissions?” Yes. A shocking figure. Concrete, my beloved building material, foundation of civilized life, is a major producer of green house gases. It pains me to think it but knowledge is power and we need to look head on and decide how to adjust. Here are some other figures: Electricity production is 29% (if you think your plug in car is helping, think again), transportation (trains, planes, automobiles) 27%, Industry 21%, agriculture 9%. I’m not sure if the agriculture number includes production only or both production and transportation to market.

It’s easy to get overwhelmed and think it’s hopeless. But then look at the room for small steps each of us can take to reduce these numbers. Share a ride. Walk to work once a week (live on the job site like we do?). Cut down on meat. Buy locally. You’ll be healthier and the gas savings is always nice on the budget. Try a solar oven. We love ours.

Last week we took a walk out the Point Reyes National Seashore near San Francisco. They have a display there that viscerally depicts where sea level will be in the next 80 years. Since 1880 sea level has risen 8″. It is predicted to rise an additional 1′ to 4′ in the lifetime of a child born today. The bridge above will be completely submerged. Do we build a bigger bridge?

A sign depicting projected sea rise on the current bridge.
A sign depicting projected sea rise on the current bridge.
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