Section & replace concrete for conduit burial

[Metal Head]

Hey guys, long time lurker new poster.

Take a look at the rough sketch of my house layout. The last owner built the detached garage and only ran 30A service out to the subpanel. I want to run at least 100A service out there as I have a large welder, compressor, mill, lathe etc that I want to run and would like to have the option to run a window A/C unit in the future. Right now I am the only one running anything out there but hopefully when my son is old enough he'll want to join me.

Problem is the wiring from the main panel in the garage goes up through the attic down a 3/4" conduit on the outside of my house under the concrete & into the detached garage. The patio was poured after the detached garage was built and wired. The conduit does not run all the way out to the garage, the cable is direct burial grade under the patio. The conduit would be too small to support the 100A wiring anyway.

Going around the patio and running would at least double my circuit length. There is also the septic plumbing / drane field lines and sump pump wiring I'd have to watch out for. I think my best option is really to section out the concrete lay a full run of conduit and upgraded wiring. I understand how to do the electrical work, it's the concrete work that has me nervous. What I am worried about is where I would need to channel the patio out, if I can't blend the concrete work back in when I am done it is going to leave my patio looking like a hodge podge of patch work & parting lines. I should have drawn the parting line between the patio & driveway in a different spot as it is not accurate and actually wouldn't look too bad as drawn.

Is it possible to cut a section of the concrete out and blend the repair back in when I am done or is it always going to look rough? Any other ideas? Overhead wiring is not an option lol.

 

[where2]

Basically, your options are: 1) Run the long way with heavier wire. 2) Rent a concrete saw, snap a chalk line, cut a straight edge, and look at the crack as long as you own the house.

I've never seen a concrete repair along an obvious straight line trench that didn't look like it had been cut out.

If the layout is "roughly" as you have shown, you might consider putting a demarcation line of paver bricks in the area you have to cut out, rather than repouring concrete. That way, it would be more of an obvious delineation between the patio and the driveway.

Where is the man door out of the back of the garage, and what material is the driveway made of?

 

[Aceman]

Does your meter base have a breaker in it for your house panel and is your house panel fed with a 4 wire cable?

 

[Metal Head]

Basically, your options are: 1) Run the long way with heavier wire. 2) Rent a concrete saw, snap a chalk line, cut a straight edge, and look at the crack as long as you own the house.

I've never seen a concrete repair along an obvious straight line trench that didn't look like it had been cut out.

If the layout is "roughly" as you have shown, you might consider putting a demarcation line of paver bricks in the area you have to cut out, rather than repouring concrete. That way, it would be more of an obvious delineation between the patio and the driveway.

Where is the man door out of the back of the garage, and what material is the driveway made of?

I think you are right about the concrete repair, I don't see how it could be made to look seamless with the aggregate patterns and all. I think it will be obvious. I like the brick idea, it is one I had been considering.

Unfortunately no man door. Garage door near the back of the shop on the same wall as the subpanel and two on the front facing the driveway. Driveway and patio are both concrete.

Does your meter base have a breaker in it for your house panel and is your house panel fed with a 4 wire cable?

I don't think the meter base has a breaker, it is just a locked box. The main panel has the two power cables, neutral & earth ground.

 

[rburke65]

You won't be able to match the old and new concrete, in my experience.