Sunday, December 12, 2010

Filling in the South Pit

December 2010

The pit is done (at least in the short term). Several days of shovelling dirt from the dirt piles in the back yard into the wheelbarrow and then dumping it into the pit has both eliminated the dirt piles, and filled in the pit.

The dirt in the dirt piles was what I saved from digging out the pit (and other parts of the yard). Mostly it would then be the heavy clay that is native to this area. But it also includes some amount of sandy loam that some contractor would have brought in, and some amount of better, composted soil that we brought in later. But still the bulk of the dirt is not very good. So to improve the soil quality, I mixed in 32 bags of leaves, and about 30 bags of "organic humus".

The "organic humus" is the least expensive soil additive from Lowe's. It's mostly semi-composted wood products. It looks like pine needles plus other stuff. The leaves were from the neighbors. It being Fall, lots of people rake up their leaves, put them in bags and leave them on the curb for the City to pick up. I picked up some of these bags and brought them home.

As I was breaking up the dirt piles and shovelling it into the wheelbarrow, I mixed both the leaves and the humus into the soil. The theory is that this will add organic compounds to the soil, and make it better soil. It certainly makes it lighter and airier. I expect it to settle quite a bit over time in the pit.

The two spots in the back yard where the dirt used to be piled are now just barren dirt spots.

I've tried to spread some grass seed and put down a layer of organic humus on the top of each area. If we were to get any rain, the grass might grow and help keep the dirt in place. If this doesn't work, I'll try something else next Spring.

I have receipts for 30 bags of the humus from Lowe's this month $46.76, plus there were probably a dozen from a previous purchase. In addition, it was taking days to move the dirt from the piles into the pit, so, since time was of the essence at this time of the year, I hired a day laborer to help with shovelling. $80 for a days work. This allowed me to finish up the digging in one day.

Saturday, December 4, 2010

Finishing the South Pit

So first we take the rocks out to the curb. Line them up along the curb.

Then we put a notice on Craig's List and wait for people to come take them away. In this case, I put the notice up on Saturday. On Sunday, we drove my daughter back to college. In the four hours to do that (from 1 pm to 5 pm), all the rocks disappeared. All of them plus 4 or 5 that were to the left of the above picture, from our own rock garden.

Now the pit is empty. We have, occasionally over the past decade, had problems of things digging under the fence. Dogs, cats, possums, armadillos, skunks -- don't know what it was, we could just see the hollowed out area that they used. When we dug out the Bamboo Grove, we put a stone wall around it at ground level next to the fence. Since we have it all dug out, let us do that here too.

First we pour a cement wall down to bedrock. Just as with the bamboo grove, we use a 1x4 for spacing, and a piece of masonite cut down to eight feet by 16 inches for the framing. We stack up bags of dirt next to it to keep the framing in place. The bags of dirt are just mulch and compost plastic bags filled with dirt from the pit shovelled into them. This picture shows the result on one fence.

And here we see the process in progress on the other fence. When we were digging straight down from the fence, to get the back side of the cement wall, we hit a couple more rocks. In particular the really big one in the following picture. I was able to move it out with a pry bar, but it was too heavy to move. Before pouring the cement, I used the jack hammer to break it in two pieces and rolled them up the pile of dirt in the pit to the edge, then out to the front to take the place of a couple of our missing rocks.

It took 29 bags of cement (from Home Depot at $3.10 each), and 4 bags of mortar ($3.77 each) for this work. The limestone rocks for the top were left over from the previous work on the Bamboo Grove

Once the cement wall is poured, I can then mortar limestone blocks on top of it to finish it off. Once the dirt is back in the pit, all you will be able to see will be the top of the limestone brick, as an edging. It should keep things from digging under the fence, including animals and roots from trees or anything. It may make it easier to mow or edge the lawn.

It is not clear what effect it will have on drainage. In theory any rain in the yard will sink down and be stuck here, unable to soak under ground down the hill. But it's well away from the house, and I assume any plants in this area would welcome any extra water. (Plus, at the moment at least, any water can just go to the right and around the wall, since the wall is only at this corner (and the opposite corner, where the Bamboo Grove is).

This gives a pit about two feet deep and 16 feet by 24 feet. The next step is putting all the dirt that I dug out back into the pit. To increase the quality of the dirt, I will add compost and vegetation. Luckily it's now Fall, and the trees are dropping their leaves. I should be able to get bags of leaves from the neighbors to add to the dirt as I put it back in.

The bags of dirt from the Bamboo Grove that I used for the forms were mostly limestone rock dust, from when the utility trench was put in thirty years ago. Apparently when they are bagged up, get wet, and sit around for 6 months, they get hard and are not of much use. So I took them to the Travis County Landfill, $18.60. I had previously taken a load of loose rock out (another $18.60), but am now trying to get rid of the loose rock on Craig's List.