What is the least destructive way to cut two slots in my slab for PVC pipes?

OK previously I had to cut a small trench (4" wide) in my concrete slab in the kitchen to bury a drain pipe for the sink in the island. The trench was

9' long I cut it with a angle grinder and a demo hammer drill and it was not too bad, I put the 2" PVC drain in and poured concrete over it no problem.

Now I have to cut two more slots to accomodate a new 3/4" PVC electrical conduit, one in each slot. The length is about five feet, see the diagram below for my floor plan.

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What is shaded in magenta is the concrete slab for the interior part of the house, the upper left corner in blue is the garage where the slab is 6" lower in elevation.

The slab is 4" thick and it continues to the interior courtyard (shown in yellow). The cyan color area is the pool. You will see that there are several planter areas in black. On the left side you should see two thick red lines. I need to run a 3/4" PVC electrical conduit along those lines. Because of the fact the cut especially the one on the upper left is going to come pretty close to the garage on one end and the planter area (no slab there) on the other. I am concerned about cutting a trench there will cause a crack that will never really heal and will become an "expansion joint" of sort.

So my question is, what is the least destructive way to accomodate the 3/4" PVC pipe?

Options:

(1) Cut a slot about 1" wide and 1" deep, put the pipe in, pour concrete to seal off excess space then lay pavers back on top. (2) Cut a 1" slot all the way through the 4" slab, put the pipe below the slab then put back concrete and paver. (3) Excavate the planter area soil down to 3 or 4', then do a mini tunnel with the pipe to try to bridge the 5' length below. Then break a small opening on the other side near the wall, and put in an elbow to the pvc pipe, that way the slab is not being cut at all...however I can see many things that could go wrong.

Thoughts?

MC

Reply to
MiamiCuse
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Use water pressure to dril under the slab?

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Use one of these:
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Reply to
Limp Arbor

Go under the slab. It's easy with the right tools.

The one I saw used several joints of pipe with a pointed tip on the first. You start with a four-foot long trench next to the slab, connect water to the pointy pipe and push (pound) it in to the soil. When it's 4' in, you disconnect the water, add a joint of pipe, reconnect the water and proceed. Continue this process until you reach the target.

Oh, you'll also need a pump to keep the water out of the trench.

You probably don't have this equipment in your garage, but there are individuals and companies that do.

Reply to
HeyBub

Any reason why you can't do the electricals with a drop from above? Some installations I recall in fancy brochures use pot rack supports as one way to do it. A concrete slab is such an important structural element that any compromise to the integrity should be the last thing to consider, even if the esthetics of an alternative are not perfect.

Joe

Reply to
Joe

The run is short, and 3/4" PVC conduit is pretty flexible. I'd be inclined to make a ~6" dia access hole at each end and push the conduit through unless the subsoil conditions are particularly bad. For such a short run I'd even consider using UF cable and skipping the conduit.

Reply to
Pete C.

I would also go under the slab,

Reply to
zzyzzx

Any reason why you can't do the electricals with a drop from above? Some installations I recall in fancy brochures use pot rack supports as one way to do it. A concrete slab is such an important structural element that any compromise to the integrity should be the last thing to consider, even if the esthetics of an alternative are not perfect.

Joe

Yes, several reasons. I don't really like to create two floor to ceiling obstruction in the planter areas, and above overhead is actually an overhead screen. The screen is sitting on structural fascia attached to an interior structural gutter because of the design of the house the water has to be directed away from the interior courtyard using super gutters. Cutting through those will be much more devestating.

Reply to
MiamiCuse

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