Just like lego
Less than 24 hours after pouring the footings, we were back at work on the foundation walls. I spent a lot of time debating what I should do for the foundation. Since the building doesn't have a basement, I could have poured the concrete floor on compacted gravel. This is known as a 'slab on grade' foundation and it's often used in the arctic where it's impossible to dig below the frost line. Insulation is extended beyond the footprint of the building to prevent frost from forming under the building. While slab on grade would have been cheaper, my dad and the engineers were worried about frost moving the slab so I went with a foundation wall to support the building's structure. We used insulated concrete forms (ICF) to build the foundation walls. ICF is the same product Perry used to build my house. The forms look like Lego blocks made from rigid insulation. A plastic web holds the two sides of the block together and is used to support the rebar. The 6-inch center of the block is filled with concrete to create the insulated wall. A really neat system. As part of the foundation wall, we had to build six concrete piers to support the steel moment frames. The moment frames are designed to transfer wind or seismic forces on the production walls/roof down through the concrete piers to the bedrock. The moment frames are attached to the piers with massive 1-inch bolts. The steel maker gave me plywood templates so I could position the bolts before they are cast in the concrete. I asked him how much of the bolt should I leave above the concrete and he said 1.5 inches would do. On the day of the concrete pour, it was my job to place all the bolts. I struggled to get the bolts past the rebar in the walls. Most of the bolts were sticking up 2 inches more than they should be. My dad was concerned about this but I said we could cut them afterwards. Friday turned out to be a perfect day for pouring concrete. The Cavanaugh trucks started to arrive at noon and Perry proceeded to guide the pumper and fill the walls. My job was to keep the anchor bolts straight during the pour. After Perry filled the pier with concrete, it was impossible to straighten the bolts until Claude used a concrete vibrator. The vibrator looks like a snake and liquefied the concrete so I could move the bolts by hand. My dad followed after us cleaning the concrete off the bolts. Except from one pier, all the bolts were dead straight. After filling the walls, Perry and Claude adjusted the bracing to make them perfectly plumb. It was nerve wracking to watch the concrete slosh around as Claude jostled the wall. I measured the distance across the production space with a laser and found the walls within 1/16-inch of plan. A good thing.