Electrical Question For Garage

[BSVLY]

Howdy, Been a while since I posted here. I have had a steel building erected and it is insulated and now I want to finish off the sheet rock. I will be installing the electrical next year as money permits.

Right now the 2 "conduit comes out of the slab inside the "wall" . It is a short piece buried outside of the garage and I'll connect to it to make the run to the pole after I dig a ditch etc. There is also a rebar ground stud coming out of the slab. The contractor ran the rebar under the footing, parallel around 20 feet.

I want to run all of the electrical wiring external to the inside walls in the garage using rigid conduit. The power will come from the Main at a pole about 60 feet away.

My questions are, since the dry wall crew is coming out soon-what to do with the conduit and rebar so that the electrician can work with it later on?

1) I know that there are special rebar clamps. Like the JRD and the EK16. I'll use one of those. I think I'll use #4 solid ground wire. But How do I run it from inside the wall to where the breaker box will hang? Do you run it in seperate conduit, or poke it through the drywall, or run it along side of the 2-inch conduit? I did locate a Kenny Clamp to secure the #4 to the breaker box knock-out hole etc.

2) Do I need to come through the sheet rock with 2" metal conduit for the run up to the breaker box? Or is the 2" gray plastic Ok? I was told you need metal above ground if it is exposed? Also-I know the white PVC 2 inch coming out of the slab is not correct. The buried 90 Degree is the gray and the guy had no gray straight sections-so he used the white.

3) And how high do you typically mount the breaker boxes? That first galanized cross beam sits centered at 38 inches.

Thanks for any ideas..

Rich

 

[JB4310]

Don't have the answers you need, especially to meet your local building codes. but just a couple of things to think about, for now just rock the wall and deal with the electric work later since it wont be for a while, just mark the floor so it's easy to find later. The electrician will be able to noodle everything out at the time of installation, typically the panel box would be fastened to a piece of 3/4" plywood attached to the wall and that's large enough to catch the framing (steel purlins in your case) in the wall and provide a stable platform.

As far as code stuff goes, not sure of the max service you will be able to bring in with just a 2" pipe, my 200 amp service required 3", also I've never heard of using rebar for a ground rod. Also not sure if you can use reg white pvc in place of electrical conduit, but even if anything has to be changed it's no big deal as you could just bring a new pipe in thru the wall when you are in the middle of all the other work, trenching and connecting to the pole.
Good luck,

 

[BSVLY]

Don't have the answers you need, especially to meet your local building codes.
Good luck,

Thanks for the input. Good suggestion on just marking it and forget about it! Although I am having all the work done to code-in my neck of the woods (desert) there are zero codes and no permits required. Nearest stoplight is 120 miles away.

I'm only putting in a 100 amp service to the garage/shop. A fellow told me I'll likely only use 60 amps. I already have an unused 100 amp breaker at the pole to feed the garage's sub box.

Of course due to relaxed codes and permits here, some of the places in this neighborhood are just junk piles IMO. We are trying to do it right and are using licensed contractors from counties north of us that do have strict codes. One neighbor claims we ain't redneck enough to fit in and recommends a blanket in the front window for drapes and a wrecked car in the yard. Ha HA

That chunk of white PVC was a screw-up on the contractors part. What is the physical difference between gray and white PVC besides the color? Maybe you don't know but someone on the board may.

Thanks again for the good info.

 

[Soundguy]

Only thing I can add is to blow a string thru the conduit while you have easy access to it.. the electrician will thank you later.

A wad of paper towell with a piece of string tied around it ( called a rat ) can be 'sucked' or blown thru the conduit using a shop vac or compressed air source... just duct tape the shop vac to the other end, insert the rat with looooong tail and fire up the vacume..

soundguy

 

[jeffinsgf]

If at all financially possible, I would have the breaker panel set before you hang rock. Depending on how picky you're going to be later, you are setting yourself up for a bunch of sheetrock repair work down the road. Similarly, I would run all the wire and locate the boxes. Otherwise you are going to end up with surface mounted wire and boxes, which are just dust traps and accidents waiting to happen. You can then install plugs and fixtures as time and budget permits.

 

[EddieWalker]

Howdy, Been a while since I posted here. I have had a steel building erected and it is insulated and now I want to finish off the sheet rock. I will be installing the electrical next year as money permits.

Right now the 2 "conduit comes out of the slab inside the "wall" . It is a short piece buried outside of the garage and I'll connect to it to make the run to the pole after I dig a ditch etc. There is also a rebar ground stud coming out of the slab. The contractor ran the rebar under the footing, parallel around 20 feet.

I want to run all of the electrical wiring external to the inside walls in the garage using rigid conduit. The power will come from the Main at a pole about 60 feet away.

My questions are, since the dry wall crew is coming out soon-what to do with the conduit and rebar so that the electrician can work with it later on?

1) I know that there are special rebar clamps. Like the JRD and the EK16. I'll use one of those. I think I'll use #4 solid ground wire. But How do I run it from inside the wall to where the breaker box will hang? Do you run it in seperate conduit, or poke it through the drywall, or run it along side of the 2-inch conduit? I did locate a Kenny Clamp to secure the #4 to the breaker box knock-out hole etc.

2) Do I need to come through the sheet rock with 2" metal conduit for the run up to the breaker box? Or is the 2" gray plastic Ok? I was told you need metal above ground if it is exposed? Also-I know the white PVC 2 inch coming out of the slab is not correct. The buried 90 Degree is the gray and the guy had no gray straight sections-so he used the white.

3) And how high do you typically mount the breaker boxes? That first galanized cross beam sits centered at 38 inches.

Thanks for any ideas..

Rich

Rich,

I'm a licensed General Contractor here in Texas. Most of the areas I work in don't have any code, so it's sort of a free-for-all in what I come across. There's always varying degrees of the way things have been done that I come across with some being so bad that they are hazards waiting to happen. Most are just shortcuts that people take not knowing anybetter that are easy to fix or upgrade.

In your situation, I don't really see any issues. The rebar is an excellent ground. I've heard that in some places it's now code to have your ground tied into your foundation or metal water pipes. From what I understand, soil types have allot to do with how effective the ground rod works when hammered into the ground. Some soils are very poor for grounding electricty and when tested, you need multiple ground rods. This is also true for larger loads, but doesn't apply in your case with only 100 amps. Multiple ground rods spread add the the surface area of the ground rod and increase it's effectiveness. With the rebar as a ground rod, you have no doubts that you will be properly grounded as it's making more contact with the soil in multiple locations.

As for the white versus grey PVC for conduit, there are some things to consider. Grey is the standard color and code because of that color. Grey also comes in Shedule 80 for exposed areas that require the extra strength. It also comes in Shedule 40, which is the same as heavy duty water line, white PVC. When burried under ground or in the slab like yours, shedule 40 is more then enough. Strength wise, your fine. If it's a code issue, which you say doesn't exist, then there might be a concern, I wouldn't think twice of using it just the way it is.

Relying on the electricians to come in and pull the electrical after your sheetrock is in place is just going to make it more expensive for you down the road. First, wire is just going to get more expensive. I would strongly suggest that you install the wire now. It's a simple do it yourself project to dig the trench and put the wire in place. You don't have to connect the ends to anything, just leave a few feet of extra for the electrician to work with.

Mounting the electrical panel is also a simple do it yourself project. They are not expensive and all you need to do it frame up some supports to hold it in place at the correct height. I like the bottom of the panel to be 4 feet off the ground myself. You can use plywood as suggested to create a back wall to attach it to, or just run some lumber up the sides and attach it to your posts with bolts or screws.

The reason you don't want to do this after the sheetrock is in place is to do it right, somebody is going to have to tear out a bunch of sheetrock. In my experience, electricians are only good at what they do. They don't really care about sheetrock and figure whatever damage they do, is somebodye elses job to fix. Here, you pay $65 an hour or more for this service and still have to hire a sheetrock guy, or handyman, to come in and fix what they did for at least a couple hundred bucks.

Once you get the panel in place, it really makes allot of sense to run your electrical lines. This is also an easy do-it-yourself project. The trick is to determine what you will need and size the wiring accordingly. Most shops work fine on 20 amp outlets with 12/2 romex wiring. Figure one 20 amp cercuit for every 5 to 6 outlets and you'll be fine. Run your lights on a different their own cuircut as well as each 240 volt line. Also put a dedicated outlet in for your air compressor, even if you don't have one yet. Every shop has to have an air compressor sooner or later.

Doing this before you put your sheetrock up with save you hundreds and hundreds of dollars. If you expect your electricians to do this, you better expect to pay a premium in added hours at the very least. Running wire through walls without sheetrock is a simple day job. Doing it with sheetrock in place turns it into a long term, drawn out project.

You don't need conduit for wiring behind sheetrock. If you run any wiring out in the open, then you need conduit to protect the wires and people from accidentally cutting them.

I strongly advice not putting the sheetrock up until you are ready for it.

Eddie

 

[desert_guy]

BSVLY
My neighbor is working his 24'x48' bulding. He is buying 100' 12/3 Aluminum-Clad MC Type Cable about once a month and he complains that every time he goes to Lowes the wire has gone up again. What Eddie said is right now is the time to do your electric befor the dry wall. you might not even want to dry wall later it is a shop not a house, that is what he tells his wife.
Craig

 

[JB4310]

I understood by his first post that everything was to be surface mounted, (which is how I would do that type of building) that's why I suggested just go ahead a have the drywall put up as scheduled and worry about the electric later, would only be a small area to open under the future box location or just leave that area unrocked for now. Sure doing the whole project at once would be great but it sounds like he's budgeting in the electric and except for the material cost rising I don't see any other cost effective reason for doing it all at the same time. Labor might be cheaper when guys may just be working for beer money the way the economy/construction is heading.

I was just worried that since his location says L.A. there would be strict, strict codes.

I like the part of not being "Redneck enough" till you get a blanket for curtains!!!

 

[BSVLY]

Thanks very much for the input guys-All of you. I do understand the approach to running the electrical first and that is exactly how I approached the shed that we put in. That one is the wife's deluxe 10 X 12 garden shed and it is all done and finished-off on the inside. The fellow that was doing the electrical work for me is a master electrician retired and 80 years old now. This shed has two ceiling lights, outside security light, sub panel, power strips at the bench level, strip heater, multiple wall outlets and even an outside outlet. More wire in that shed than in most garages! However, He just blew out his knee and has a brand new Ti knee this month. So he can't help me anytime soon dang it.

The garage/shop is a different matter though. Since I live in LA full time and the shop is 409 miles away in a remote desert location, I pull teeth to get anyone to come out and work on it. The main thing though-I have to finish off the sheet rock in the shop part, which is divided from the garage bays by a solid framed wall so that I can begin gradually moving things over on weekends etc. Since I got a crew to come out-they are going to dry wall the shop area floors and ceiling and the walls-only in the garage portion. I'm on a two year plan for this move to the "Farm" and want to do this smoothly and economically as possible. The more stuff I haul out there and stuff into the garage-the worse it gets for having to move stuff out into the weather and back again to do make room for the dry wall crew and me painting it properly. I need to get it rocked/painted and get some benches installed so that I can start getting some bench tools going etc. I can get power into the garage via some 20 amp quad boxes ina few spots the yard for temporary juice.

Mostly though- I have a huge "piece of shop equipment" and the manufacturer just picked it up from my house after 13 years and they are holding it in their warehouse for another month. Then they will deliver it and install it again in the garage right after a big show just a few hundred miles from the new place. This is the best price and schedule I could arrange. So I definately want the equipment installed ,"after" the dry wall and paint. So I am forced, in a way, to get the dry wall done because the machine is coming. I don't want to work around it and don't like trusting work crews with working around equipment like this. No way I can deal with budging this thing myself and do want to have the walls finished before it is set.

I think I can live with running external conduit through out the garage. Good point about the dust and possible obstructions. I will try to run most of the conduit overhead. Guess it will have to look like costco in that regard.

Thanks for the tip on the "Rat". That is a good one.

Funny-My wife made a comment on "Why do you need the walls in the garage drywalled-it is only a grage!" I think all wives go to the same school or something... I did build her that deluxe garden shed first!-and added a mud room to the house first and put in new kitchen counter tops for her first. HA HA. I do have a method here. Time for the garage!

Also-can't dig the trench yet for the e-run either. Beside the ground being frozen (Hard long winter), I've got no tractor of ditch witch. And... we are thinking about installing a water pipe underground for irrigation in this area too near-term...and want to make sure the electrical (which will cross it at 90 degrees) goes in shallower and over the top of the water run. As you can see-there are planning issues here. My issues I know-but I think I have a plan. Ha HA!

With all of the good advice here-Thanks Again, I will see about pre-mounting the breaker box bracing and shore it up properly. The drywall crew is installing 7/8 steel hat section throughout to hang the rock from. Had to do this because the steel building was bolted together and there are huge bolt heads coming out of every beam.

I'll work with the dry wall crew on the box location too to get this part right. I'll pre-connect the ground wire to the rebar at least-since I have it on-hand and also the proper clamp, and try to bring make the emt to PVC connection and then bring the EMT through the wall too. If not-then I'll mark the floor and figure on making an access door down there to allow the electrician (TBD) to get at that stuff.

Thanks Eddie, as usual, for the data dump. I will hang that E-box bottom at 4 feet.

..and lastly-I'll grind away on all of this good input see what all I can do to make things correct and fun...

Rich

 

[podagrower]

Another thought about the electrical box.
If the box is recessed, and the conduit is exposed, where the pipes go into the wall will look like a bag of hammered ...um... holes.
If you can find an electrical box--12x12 would be the correct size. They make a metal box, with a screw on cover that you could bring the 2" pipe into, set the cover flush with the front of the drywall, then remove the cover and bring the wire into the back of the panel.
Now, making a 2" hole in a metal box is easy with a hydraulic knockout set(everybody has one, right) or a 2 1/2" hole saw.