Sunday, March 2, 2014

Week 8 - Concrete poured, beaver lodge located

Suddenly, we’ve made major progress this week, despite the continued frigid temperatures! On Monday, the rebar was set into place and on Tuesday the concrete was poured. Everything seems to be going well, but not without some misunderstanding. Also, I think I’ve finally located the beaver lodge.

Pouring the concrete


When I showed up, the first concrete truck had just finished pouring its portion of the concrete and the guys were spreading out the concrete and leveling it. The second truck was on it’s way, but I had to take off.

Power troweling the concrete all night

Later that night, I dropped in to find the concrete guy floating the concrete, using the power troweler on the right. After waiting for the concrete to cure until it was hard enough to walk on, he repeatedly ran the power troweler over the concrete until he was satisfied with the sheen. The process apparently took all night — it had to be done before the concrete hardened any further. Hopefully, the neighbors weren’t bothered by the sound of the generator.

Here’s the floor in the morning. It looks smoother, but what’s all that white stuff?

Is this polished concrete?

The concrete process seems to be deviating from what I expected, and I’m not exactly sure what is going on. We had decided on polished concrete floors — an agonizing decision because of a the $5/sq ft premium over traditional concrete, with a total cost of $15.6/sq ft. For comparison, $14/sq ft is the cost of a high-end wood floor. The concrete doubles as the foundation, so it’s not a fair comparison, but still — it’s not cheap.

Polished concrete has the advantage that it does not require chemical sealers or annual waxing, and apparently the look is better. As I understood it, the process for polished concrete follows these steps:

  1. Once the concrete hardens, it is ground down to a smooth finish, exposing the aggregates in the concrete.
  2. A densifier is applied to the concrete to harden it, providing a hard surface that does not need maintenance. The densifier is a non-toxic mixture of silicic acid, potassium salt and water that reacts with the concrete to produce calcium silicate hydrate, a super-strong material.
  3. The hardened concrete is ground down to a progressively finer finish until the desired polish is achieved.

It looks like the concrete guy is actually going down a much different route, which might end up fine, but I’m worried about getting a floor that looks like a basement rather than something that suits a living room. One aspect that concerns me is the troweling process, described above. Apparently this process buries the aggregates under the surface of the concrete, giving a more homogenous appearance that is typical of a concrete floor. But the texture that the aggregates provide seems to be partly what makes polished concrete look so good. I’m crossing my fingers that it will turn out OK. I’m also wondering where the $5/sq ft premium went.

On Friday, after a couple of days of curing, the densifier was applied. I’m hoping that those scuff marks are not permanently engrained in the concrete. I guess there’s no turning back now.

Here’s one of the two massive propane burners, running 24/7 for a week now to keep the concrete warm.

Did I find the beaver lodge?

To relieve my worry about the concrete floor, I decided to go check on the beavers. I think I found their lodge, but I’m bothered by the fact that it is so close to the trail — it seems like I would have seen it earlier. Notice the pile of sticks covered in snow, right at the center of the photo. It could be a random pile of sticks, but the location makes me think it is a lodge. Look at how the lodge is situated right at the crux of the stream’s oxbow — this is exactly the same positioning as an abandoned beaver lodge further down stream. My guess is that they’ve installed two entryways, one downstream and one upstream.

The beaver dam is still holding up well. This most extensive dam in the area. Starting from the lower right side of the image, the dam runs diagonally and then continues to zig zig into the distance, making it’s way to the hillside that you can see in the background — a massive work of engineering.