Saturday, October 18, 2008

Before pouring concrete, we needed to clean out the holes. The base of many of the foundation holes needed to be shifted at least an inch or two. This was hard work, since it was 90 degrees outside, we had to break through more of that Palouse clay with our shovels, and the holes were not quite wide enough to lean down to remove dirt.

We did find about a dozen of these beautiful salamanders trapped at the bottoms of our holes after only one night. The must have fallen in accidentally and were unable to climb back out. Here you can see me holding one of the little guys...

The children loved the holes, too. We made sure to remove them before pouring concrete... :-)

We added 6" of compacted 3/4 minus gravel to the bottom of each hole.

After measuring and re-measuring and re-measuring, we positioned the footers and sonotubes in their correct relative position and then we backfilled our holes. Of course it felt a little frustrating to fill in the holes that we painstakingly cleared out...

The concrete is reinforced with rebar. We have a grid of rebar inside of the bigfoot footers, raised above the gravel layer by pieces of brick. We have 4 pieces of vertical rebar lashed to a brick and to each other with wire.

Peter developed a simple way of building the rebar mesh using a brick and some wire:

Peter and I mixed 30 bags of concrete with water by hand using a tarp. You place an 80-lbs bag of pre-mix concrete on the tarp, add water, and jostle back and forth like a mixer. When the concrete is mixed in the tarp, then you use the tarp to pour the wet concrete into the sonotubes.

Before pouring all of the concrete, we positioned our angle-iron into the sonotube. The angle iron has a piece of rebar sticking through its base, which will serve as an anchor, helping to resist uplift of the angle iron out of the concrete.

Ultimately, we will weld a custom horizontal plate to this angle iron. This custom plate will attach to the timber sill plate of the artist's studio.

We used some hand-made forms to hold the angle iron in place while the concrete dries. Here, you can see all six finished piers starting to dry.

The pier foundation turned out great!

I think both Peter and I were excited to be done with this phase of the project. Now, we must focus on acquiring logs, milling them, and preparing to cut the joinery this winter.
Since the Dingo was not able to bore through the tough Palouse clay, we rented a Bobcat with a 24" auger bit. The Bobcat weights 4 times more than the Dingo, and this extra weight allowed us to ultimately push through the clay and excavate our holes for our pier foundation.

Our 10x14 footprint is small enough that navigating the Bobcat between the holes was a challenge.

Using the auger on the Bobcat was so simple and easy, that we ultimately dug our holes deeper than 50", when we only needed to go around 30". The extra depth will only serve to make a stronger, more stable foundation.

If you look closely at the following picture, you will see some local wildlife hanging out in the holes.

All six pier holes were close to their ideal location. However, some work was necessary to clean out the holes and make sure we could position our bigfoot footers and sonotubes correctly.

After that, its time to prepare to pour the concrete...