Plunking Under a Driveway
So you forgot to have your builder put a pipe under your driveway to allow retic to be fed thru?…
That makes it tricky.
You have two options. If its a paved driveway you can lift and relay the pavers, which will take a couple of hours, or if its concrete one you can ‘plunk’ under. Plunking is a not so technical term for using water to push pipe through. You can easily plonk under paths, but driveways take a little longer.
Its not recommended for full width paved driveways as the water can erode the sand under the pavers and cause them to subside, but for concrete its the only way.
As we are in the process of having a bore installed I have needed to do this at my own place. Fortunately my driveway is thick concrete and the soil is beach sand, so it is an easier option than some others.
I was hoping to plunk right under the concrete and the paving, but I ended up needing to life the small paving section and rejoin the pipes.
The pictures show the entry point (on the low side of the land) and the exit point on the other side of the pavers.
Some tips for plunking:
– make sure your hose is long enough
– cut the tip of your PVC at a 45 degree angle to give it some cutting power
– insert a piece of copper pipe into your hose and crimp it so it sprays a jet of water
– use one piece of pipe as the flanged join will impede progress
– stick at it. You might need to have two or three gos at it over a wide driveway but sooner or later you will get there.
– if you are plunking a main line as I was then consider that you may need to send cable under as well and tape it to the pipe, but don’t be surprised if it comes off in the pushing and thrusting
If you are working with a paved driveway then look for the least disruptive line to lift (remembering that the line beside the kerb is likely to be on top of roadbase).
You may find paving hard to lift so a mattock levered under the pavers may help, or some water sprayed between the edges may free them also.
Once you have lifted them and dug a trench use a trowel and mallet to level the ground and bang them back in. Its better to have them sit one or two ml high and have room to sink than have sit dead level or under the level.