Digging up the Central Backyard, Part 1

With the wall around The Jungle finished, we can turn our attention to excavating the Central backyard.

We start by continuing the work that was necessary to do the wall, particularly digging all the way to previous work, behind the Jungle and up to the fence.

This is pretty simple work -- dig down to bedrock, separating the rocks (which we haul off) from the dirt.  Mix the dirt with leaves to increase the amount of organic material in the dirt.  Put the dirt to the side, out of the way of more digging.

 
We can't dig too far to the left, since we need a pathway to get from the house to the compost pile behind the Jungle.  So we chip away at the edge of the yard

until we realize we need to be more organized about this.  That leads us to draw a couple of lines on the ground.

and we will take off all the dirt to the right of the line, up to the sidewalk, and then start digging across the yard, next to and parallel to, the sidewalk.

all the way over to the yucca plant and the part of the yard that is finished. This is roughly a rectangle 16 feet long and 10 feet wide.

With that decided, we can just start digging.  This takes all our tools -- shovel, hoe, rake, the barrels of leaves, and produces lots of rocks.

and day by day, we get more digging done.

This is exposing another layer of rock that we will need to take out.

Another day gets us all the way to the sidewalk.

Four days of digging, breaking up rock, and clearing it out, gets us to a more finished situation here.

Now we turn to dig across the yard.   First we dig one section.

and then widen that with another section.

and another.

until we have most of it dug up.  There is still a strip next to the sidewalk that is protecting the main irrigation water supply line.

And we stopped before going all the way to the finished lawn because we have hit a very large hole in the rock.  There is an area which was previously dug up where the shin oaks were before they were moved to the South-East corner of the backyard.  We moved them back in February 2011.  So this is a different type of yard to dig up from what we are working on -- dirt on top of rock.  In the section that is yet to be dug up, it should be just dirt.

So for this section, we start with a layer of rock.

and using the jackhammer, we reduce this to smaller pieces of rock.

A couple of days of cleaning up that leaves still a couple of large rocks

which again, with the help of the jackhammer can be reduced to more manageable chunks.

and then cleaning that up

leaves a big new clear area to continue work from.

Next we turn back to the strip going back to the fence.

Note the section to the left of the white PVC pipe, going from the corner back to the fence.  After a few days of digging, pulling out the rock, mixing the dirt with leaves, we have

Finishing the wall for The Jungle

We have a plant bed in the back yard which we call The Jungle.  It was originally developed back in the 1980s to keep some trees and to add some plants around it.  There were two types of plants: something and Nandina.  Over the years (decades), the Nandina has taken over, so it's just the trees and the Nandina, pretty much.

Nandina is a cousin of bamboo, and like bamboo, it likes to spread via its roots.  There is a short stone edging around The Jungle, but the Nandina spreads into the yard by going under the edging.  So as long as I'm digging up the yard anyway, I'm also putting a wall under the edging that goes down to bedrock, to keep the Nandina from getting out of The Jungle.

Previously I did the section by the Bamboo Grove, and by the Bottoms, so there is just one section left.

We dug out the yard around this edge of the Jungle, and kept digging until we hit the dirt that had already been excavated behind the Jungle.

Then we had to clean up the area under the edging -- cleaning out the dirt, the rocks, and the roots.

Then we framed it up to pour a concrete wall under the edging.

We only got half of the area filled the first day

so we framed up the second half and did that the next day.

That finished off the concrete.  It took 16 of the 60-pound Quikrete bags of concrete to build the wall, plus an 80-pound bag of Mason Mix to finish it off.

We used Mason's Mix to smooth off the wall surface and especially the interface between the stone edging and the wall itself.  Also to mortar in a rock in the missing part of the edging at the far left of the photo.

Digging up the Central Backyard

The East side and West sides are pretty well done now, so it's back to the central part of the backyard.

We have mainly been using the backyard as a staging location for the materials for our work -- piles of dirt, rock, and mulch.  But it is time for it to be the main focus of our work.

Our plan is to dig from the West and go down a couple of feet, mixing the dirt with more organic material as we put it back in place after removing the rock.

We begin at the edge of the work on the River of Rocks, first making sure that we know where the main irrigation water supply line is.

and then we continue removing the dirt from the layer of rock along this front.

and more digging.

and more digging.

This will continue for a while.  Let's see if a video can show what we do.

 

 Eventually, we dig all the way to the wall around the Jungle.

and then we start removing the rock, putting it up on the lawn, to expose ... more rock!

We can use the pry bar to separate out some of the larger pieces of rock,

but we will need the jackhammer to make them into small enough pieces that we can manage.  A day of work with the jackhammer:

followed by a week of moving rock and cleaning up the debris:

yields a new lower level for the yard and a yard full of large rocks which we will need to get rid of:

Edge Trim for the New Raised Garden

With the new raised garden constructed from sheets of corrugated steel, standing on end, the top edges are the most exposed, and are quite sharp.  We need some way to dull them, to prevent cuts and scrapes.

After some looking around, it appears that what we need is an "edge trim".  Searching the Internet, we find a company called "Trim-lok" that makes such things, and has a large variety of them.  We think the steel sheets are about .025 inches thick, which leads us to wanting the 750B2X1/32 edge trim.

But all the documentation discusses a straight edge, not a corrugated (or wavy) edge.  Luckily, Trim-Lok is willing to send us a sample, and trying to install the sample on the corrugated steel sheets shows that it works fine.  Trim-Lok sells it in 500 foot rolls, but we only need 26 feet (the circumference of the 65 inch by 90 inch raised bed).  But they point me to Grainger who carry the 750B2X1/32 edge trim in 25 foot lengths ($34.21).

Then it's down to installing it.  This took more work than I thought.

Mostly it slips on pretty well -- the plastic body has enough flexibility to bend first one way and then the other, back and forth following the curves of the edge of the corrugated sheet metal.  It was a bit like weaving.  Position the edge trim over the sheet metal and then push down to insert the metal edge into the edge trim.

The hardest part was where two sheets overlapped.  At these sections, we have two sheets of sheet metal, but the edge trim is wide enough to just barely fit over them.  We used C-clamps to hold the metal together while putting the edge trim over them.

We first did the back wall, then the East side, the front and the West side.

And once the trim was all in place, we could fill the raised garden right to the brim with dirt.

Cleaning up the outside of the Greenhouse Raised Bed

During construction of the Raised Bed where the greenhouse used to be, the sides occasionally collapsed as we built the inner walls from corrugated sheet metal.  For example, here, on the West side:

While we are waiting for the new dirt to be delivered, we figured we should at least even out these areas, and possibly clean out any rock still in the areas adjacent to the new raised bed.

So we started digging out one side.

We dug out until we hit the underground irrigation system and then down until we hit rock.  Then we got out the jack hammer and took out the rock.

We worked our way around the corner and across the back of the raised bed also.  First moving the dirt, and then taking out the rock.

Then we put the dirt back in place.

The last side had to wait a bit; we took delivery of the dirt to fill the raised bed.

And then it rained.  But eventually we got to digging out the front section outside the raised bed.

After a day of jack-hammering, the rock was broken into many pieces and removed.

Then we could fill the dirt back in, and bring in more of the really good dirt that we bought and had delivered, to finish off the dirt on the outside of the raised bed.

We built a step to get up into the raised bed, and then put mulch around the entire area.

Building up the new Raised Bed where the Greenhouse was

With the greenhouse gone, and having dug down about 30 inches, we are ready to create the new raised bed.  We start with a hole in the ground, surrounded a wooden frame that used to be the foundation of the greenhouse.

The dirt sides under the frame provide an avenue for roots and such to get into the raised bed-to-be, and we would like to prevent that.  Plus we need a way to raise the bed over the surrounding ground level, maybe by 10 to 16 inches.

Our solution is to use corrugated steel sheets.  These can be bought in 8 foot lengths, and cut in half will then provide 4 foot lengths.  A 4 foot long sheet can be attached to the wooden frame so that 14 inches is above the frame, and 32 inches then extend down into the ground.

We cut the 8 foot lengths in half by using a thin metal cut off wheel for our hand power grinder.  That works pretty well.  Not a perfectly straight edge, but I can put the cut edge down and bury any issues with that edge -- the exposed, top edge is perfectly straight.

We use standard roofing screws, 1.5 inches long, to attach the corrugated steel to the frame.

Three sheets along the back wall.  The first one put up was bent, length-wise, to fit in the corner, so we have the back wall, plus part of one side wall.  We do the same on the other corner and can continue along the sides.

Then we run into a problem.  Caused by poor planning.  We started at the back.  The ground, even the rock layer that we have dug down to, slopes gently from the front to the back.  So the 32 inches of depth that we have in the back, reduces to less at the front.  The result is that the sheet we want to put on the side, again showing only 14 inches above the frame, hits the rock floor with too much showing above the frame -- 15 to 16 inches -- and won't go lower.  We could get out the grinder and cut each sheet to be shorter.  Or we can get out the jack hammer and make the ground lower (at least in a line under the sheet metal), or we can raise the frame.

We decided to raise the frame.

Doing that, we can then continue around the bed, attaching the sheets to the side and the front.

Three more sheets to attach, and once that is done, we have the complete definition of the new raised bed.

There are a couple of details.  Notice, that the corrugated steel sheets are, well, corrugated, but the frame is not.  There is a special piece of trim sold at hardware stores for this, called a closer.

Before attaching the sheet metal, I first tacked the closer onto the frame, and then screwed the sheet metal thru the closer into the frame.  It turns out the waves of the closer are a bit closer together and more "wavy" than the sheet metal.  So if you force the low spot of the sheet metal into the low spot of the closer, you accordion the sheet metal a bit more and it molds to the closer shape.


The other detail is that the ground around the frame has collapsed in spots.  This is most likely because I dug out a bit too much under the frame, combined with the fact that we raised the frame to get it level and high enough for the 48 inch height of the sheet metal.

We will need to fill in and smooth out these areas, after we fill in the raised bed with dirt.  At this point, the raised bed has some dirt in it, the dirt that we never bothered to remove from the pit after we had dug it out.

We add on top of that all the dirt that we dug out and put in a pile in the back yard, mixed with a lot of leaves and grass.  This gives us a clean back yard

and fills the new bed up almost to the point where the screws are that hold the sheet metal to the frame.

 We still need 14 to 16 inches of dirt to fill the bed to the top.  Since the bed is roughly 65 inches by 90 inches, that means about 2 cubic feet more of dirt.