Sunday, November 11, 2012

Underground Electrical Conduit

We bought 2 inch PVC electrical conduit, matching what Austin Energy does with the power line.  Byrd says that telephone and cable conduits should be at least a foot away from the electrical lines, so we positioned a separate run up the wall for the cable and telephone lines.

From the wall, we put in a 90-degree connector to change from vertical to horizontal, and then after a slight distance a 45-degree to head to the back of the yard.  A 10 foot section takes us under the bridge (and where the pathway will be) and into the main pit.

That's were we run into problems.  We need to turn the conduit to head towards the green City transformer box.  Both the cable and telephone lines originate neat the green transformer box.   But the angle we need to turn is probably something like 16 degrees.  Standard connections come only in 90 and 45 degrees.  In the picture below, you can see that both a 90 and 45 degree turn would be way too much.

But we had seen that there are two flavors of 90-degree connectors.  One is fairly small; the other takes about 2 feet to slowly turn 90 degrees.  Byrd says that is meant for fiber optics, which can't turn quickly.

We noticed that for the larger, slow turning 90-degree connector, that if we cut it at any given point, the pipe is almost straight at that point, at least for a couple of inches -- long enough that a connector won't notice that it is slightly curving.  So we can find the point where the tangent to the curve is pointing in the direction we want, and cut it there.  Then connect the 10-foot straight piece and we have a good connector for our specific angle.  The slight curvature in the connectors might mean it is not a perfect fit, but since this is for a conduit, not for pressurized water, that should not matter.

This extends the conduit all the way to the area near the electrical transformer box.

Now all we have to do is find one end or the other of the cable and telephone lines and run them thru the conduit.

Lowering the Water Supply Line

 With the foundation repair out of the way, we can begin on lowering the PVC line that provides water to our irrigation system.  The idea is to lower the line down to bed rock, as it comes out from under the path by the gate and then keep it down on bed rock along the house, around the corner and up the the edge of the current excavation.  Later we can excavate the rest of the backyard and lower more of it.

Since we are replacing the PVC line, the extra distance is not an issue.  But in addition to the PVC water line, the electrical wiring for the various zones also travels with the line.  Apparently standard practice is to dig a trench, throw the wiring into it, put the PVC pipe on top of the wiring and then cover everything over with dirt.  So the wiring now has to go down an extra couple feet and then, eventually, back up a couple feet.  So we need about 4 feet more wire.

To do this, we called American Irrigation Repair, as we have before, and had them cut all the wires and splice in an extra four feet of wire.  Each wire had to be cut, spliced on both ends, and the splice stuck in a special adaptor that keeps it waterproof under ground.

 Once that was done, we could remove all the old PVC pipe, and begin laying our new PVC.  We used "Schedule 40" which has thicker PVC walls.

We had to put in connections for Zone 2 and Zone 3.

And we then came back and connected Zone 3 to the existing piping for it.  This leads to underground drip irrigation lines in the North and South beds.

 We continued the line around the corner and hooked it into the existing PVC which runs across the backyard, where we haven't dug it up yet.  We put a connection for Zone 4 into the line before connecting it to the existing PVC.

 Before we sealed it off, we ran water to try to flush out any dirt or debris that got into the line.

And then we connected the Zone 4 control value.  We don't have a plan yet for what Zone 4 waters or where the lines go, but we have it ready.

Foundation repair

Once we have cleaned out the trench along the East side of the house, from the corner all the way to the fence, we can see that the house is not sitting on rock, but on rock on dirt on rock on dirt on rock.  And there are many tree roots going into the dirt under the foundation.  This seems to be just inviting trouble, so we would like to seal off the foundation.

We first clean out as much of the dirt and loose rock as we can.  Then we fill that space with cement.  To facilitate getting the cement in and holding it there, we use our standard cement forms, held about 4 inches away from the foundation, so we can pour the cement into the 4 inch space between the foundation and the forms.

This gets us partway around the house, then there is the area by the kitchen bay window.

 We do the same with that part -- creating a form and filling the area with concrete.

 And on around to the gate in the fence, first the forms.


and then the cement.

In all this took 72 bags of Quikrete.   At $3.10 per bag (plus tax) is $241.61.

We hope that this will seal off the foundation, making it stable.

 The cement did the main job of sealing the foundation, but notice that at the top, there were issues of trying to get the cement to seal up with the existing foundation.  Once the cement was poured, we then went back with just pure mortar mix and slathered on a layer of mortar to finish off the top of the cement and the existing foundation siding.