Tuesday, December 8, 2009

First half of concrete wall

Now that the digging is done, the next step is the concrete separating wall. We are going to put in a concrete wall, down to bedrock, to keep the bamboo in (or out) to this specific area. To be a bit more attractive, we put a rock edge along the top.

So the first problem is to get the rock. Whittlesey Landscape in Round Rock has some 4x4 rock for 7 cents a pound. I got 520 pounds for $39.40 (27 November 2009). This should be 50 linear feet or more. In the photo below, I just laid them at the base of the fence to get an idea of how much length I have, and what it will look like.

In addition, I will need concrete and mortar mix -- the concrete for the wall and the mortar mix to attach the rocks to the top. The process is fairly simple. I put a black plastic sheet on the "dirt" side, to keep the concrete from mixing with the dirt. I use 1x4's to keep the forms 4 inches away from the dirt, and then put the forms on the outside. For the forms, I just bought a 4x8 sheet of masonite from Home Depot ($12) and cut it down to 3 16-inch tall pieces. I use the plastic bags of bad dirt as sandbags, to hold the form in place. Then I mix up a bag of concrete and shovel it into the space between the plastic on the far side and the form on this side. As I shovel the concrete in, I can pull out the 1x4's -- they are just there to keep the form from collapsing next to the black plastic.

It's a dirty messy job. Part of this is because the weather was sort of wet, but also just the water to clean the bedrock, and to mix the concrete.

Once the concrete is firm, the forms can be removed (and re-used for the next section). The black plastic can be trimmed off (but you can't get it out from behind the wall -- that's intentional; it should help seal the wall from anything coming thru it). Mix up the mortar mix and use it to put on the top edge of rock.

In the photo above, I don't have all the rocks attached yet, but the part that is done looks good. I have to finish all the way around to join up with the first separating wall, and close the wall around the bamboo grove.

But there will be a delay -- I seem to have acquired "tennis elbow", and the doctor says to lay off this work until I get better. I would still hope to be able to finish by the end of the year, but there is no rush. And with the wet winter weather, it's difficult to work. And cedar allergy season is about to start.