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Garage Electrical II – Amateur Hour

2007.06.15

Now that the inspection is over and everything is good to go, I’m going to add onto the wiring in the garage, so I can hook up the automatic garage door opener, and install a fluorescent light with a switch on the wall.

Today after work, I started by climbing up into the dark unknown of the garage attic, via this four-foot-square hole someone thoughtfully cut in the ceiling.

There is a shiplap wood floor over most of the attic, and apparently there used to be windows or screened vents at the gable ends before the outside was covered with vinyl siding.  The attic seems to have been used for storage at some point, and a few junky remnants remain scattered about.  There are also opened nut shells and even some gnawed bits of bone.  Was it animals or people living up here?

The back corner is where I need to drill a hole down into the wall so I can run the wiring up and across the attic.  For some reason, on this one side, there are rough-sawn boards nailed up vertically along part of the roof framing.  I removed some of this so I could get back to the corner.

2007.06.16

I started about 9:00 this morning.  I made a small hole in the ceiling about where I wanted the wiring to come down (but inside the wall), and stuck the end of a metal fish tape up there so I could see where that was once I got up in the attic.

Drilling into the top of the wall

To drill into the top plate of the wall, I was using my hammer drill (with the hammer action turned off) since it’s the most “powerful” drill I have.  I had purchased a 90-degree adapter, and a 1-inch-diameter auger bit.

This first task was the one I dreaded the most.  To drill the hole, I had to lay down on my stomach on the attic floor, with my head bumping up against the roof sheathing, and my arms outstretched, holding the drill sideways.  Even with the adapter, I still had to drill at an angle.

A typical top plate in a wall is made of up two 2x4’s stacked on top of each other, in a horizontal position (the nominal 2-inch dimension is vertical).  What I was seeing was two 2x4’s sandwiched together with the nominal 4-inch dimension vertical.  This was part of the ceiling / attic floor framing.  With the top plate underneath, I anticipated about seven inches of wood to drill through.

I got about two or three inches down, before the drill bit hit something really solid, stopped suddenly, and the drill lunged, sending my left hand smacking into the roof sheathing and right into a protruding nail.  Ouch!

So I went back to the house to doctor that up and put on a band aid.  Then I climbed back in the attic, got in position, and tried again.  The bit locked up again, the drill went spinning, and I smashed my right hand into the roof sheathing.

So I got back down to take care of that, then got back in position, and carefully tried some more, but to no avail.  The drill vibrated so much it shook the entire garage.  What was I hitting down there?!

I decided to try a smaller drill bit.  What I really needed, I decided, was an extension, so I could hold the drill further back, eliminate the 90-degree adapter, and maybe get more torque into it.

So I drove off to Home Depot.  The extensions I saw there either looked too chintzy, or way too large diameter to fit in my drill.  So I went to Lowes.  Same thing there.  I reluctantly bought one of the smaller ones.

Back in the attic, the extension seemed to work ok, but it did make the drill bit wobble quite a bit.  And I still couldn’t seem to drill any further.

Alternative wiring route

In frustration, I decided to abandon the idea of drilling down.  Instead, I cut a hole in the wall just below the top plate, and a hole in the ceiling near the wall.  A friend had given me some leftover odds and ends from some of his electrical work, which included some PVC conduit 45-degree bends.  I could use a couple of those to run the wiring through.  Not pretty sticking out in the corner of the garage, but, so what, it’s just the garage.

I hauled the 250-foot roll of 12–2 wire into the attic so I could start fishing it down.  I could have gone the other way, but I was not yet sure how much wire I would need in the attic, so I wanted to have plenty up there.  I fed it down through the hole in the ceiling, then climbed back down.

I started feeding it through the hole in the wall.  I got about four inches before I seemed to hit something solid.  Really?

I had already pulled the two-gang box out of the wall that the electrician had installed.  So using that hole, I started running the metal fish tape up.  It went up quite a ways… then seemed to stop about where the wire had stopped going down.  I decided (with some indignation) that some overzealous carpenter had nailed in 2x4 blocking four inches below the top plate.

Rather exasperated at this point, I stopped for lunch and a long break.

After the break, I decided that I would start enlarging the hole in the wall until I found the obstruction.  Then I could cut it out with a reciprocating saw or something.  First I used a hammer and nail to poke little holes about half an inch below each other, until the nail hit something solid.  That should be the spot.  So I started sawing away with a drywall saw, and cut the hole down until I hit… nothing.  Right.

The photo on the left I took by sticking the camera in the hole cut for the switch and outlet, and pointing it up.  Looking at it later on the computer, I realized that there was indeed some sort of auxiliary framing, but it was only along the outside, not blocking the path entirely.  I’m sure that was what I was hitting though.

At any rate, the larger hole allowed me to bypass the obstruction and get the wire down to the outlet.  I guess I’ll have to patch the drywall there one of these days.

Ceiling receptacle box

Near the back of the automatic garage door motor is an old round electrical box in the ceiling.  It is so shallow, there’s no way a regular outlet could have fit in there, so it must have been for a bare-bones ceiling-mount light bulb socket with a receptacle on it (a common bathroom fixture many years ago).

When I unscrewed the old box, I discovered it was right below a couple ceiling joists.  Well, so much for that location.  I moved over a few inches into the joist bay, traced around my new rectangular box with a pencil, and cut a new hole for it with a drill and drywall saw.  Then I used the auger bit to drill a hole through the attic floor.

Wiring through the attic

After that, it was back up to the attic to route the wiring over to the new ceiling receptacle.  I made sure I had more than plenty at that end, then cut the wire with dykes (diagonal wire-cutting pliers).  I ran the wire through conduit.

Generally in an attic, code allows you to run insulated wire as-is, using special staples to attach it to ceiling framing frequently enough to prevent significant sagging.  However, this assumes you are running it along the sides of the framing, not on top where someone might step on it.  While I probably could have gotten away with just running the wire along with staples, I had decided to buy some 3/4-inch-diameter flexible aluminum conduit.  This should prevent the wire from being crushed underfoot (which might break a wire inside, causing a short), and as an added bonus, keep the rats and squirrels from gnawing on it.  Zzzzt.

The ends of the aluminum conduit are pretty sharp, and could cut into the wire (again, causing a short).  You are supposed to use a plastic sheath at the end, but of course I forgot to buy some, so I improvised with electrical tape.  At each end, where the wire exits the conduit and goes down through the ceiling, I hammered in an insulated staple to hold the wire in place.

The bane of my existence

The camera flash illuminates a lot of things that I just could not see when I was up in the attic.  Also, since it is obviously smaller than my skull, I could hold it out into tight corners out of my direct line of sight.

So it was only late this evening, after downloading the images to the computer, that I finally could see what was stopping my drill bit, preventing me from drilling through the top of the wall and running the wire inside nice and neat, rather than the clumsy workaround I settled for.

A screw.  They had to put a screw right there.  Thanks.

2007.06.17

Ceiling receptacle box continued

I picked up where I left off yesterday evening, wiring up the new receptacle on the ceiling.

Within the range of plastic electrical boxes (they still make metal ones too, but they’re not used as often), there are two basic types: new work and old work.  The old work boxes are designed for situations like this, where you want to put in a box in existing drywall.  When everything is bare framing, you nail the boxes into a stud.  The old work boxes have these little tabs attached to screws.  You slip the box in place, then as you turn the screw, the tab rotates out, and then tightens down behind (or in this case on top of) the drywall, thus holding the box in place.

Well, at least that’s what is supposed to happen.  One of the tabs worked fine, but the other one would not cinch down, no matter how hard I tried to turn the screw, either by hand or with a drill.  I gave up and tried to run a screw alongside the box, but it didn’t hold very long.  Hm, I’ll have to fix somehow eventually, but for now, I’ll move on.

At any rate, I stripped off the outer insulation and prepared to wire the new receptacle.

Electrical 101

Although as a kid I helped my dad pull wire through the walls a few times and watched him wire things up, this is my first experience on my own.  So I got out the electrical books and took my time.  It’s pretty straightforward though, at least for simple tasks like this.

Bare (ground) wire goes to green screw.  White (neutral) wire goes to silver screw (zinc-plated steel).

Black (hot) wire goes to gold screw (brass).  Push all the wires into the box (as neatly as possible), tighten down the two screws on the receptacle, and there you have it.

Connecting to switched receptacle

At this point, I turned off the garage breaker in the panel so it would be safe to work.

Connecting back to the switched receptacle was a little more involved, if for no other reason than there are just more wires in the box.  As with most (but not all) receptacles, this one has two sets of screws on each side for the hot and neutral.  By code, you cannot put more than one wire under each screw.  With only one of each occupied, I attached the neutral and hot wires from my new wiring to the unused screws.  The ceiling receptacle is “downstream” from this receptacle in the corner.  There is only one ground screw on a receptacle, so to connect more than one wire to the ground, you have to do something called a pigtail, where a short piece of wire connects to the screw, and then the other two or more wires get twisted around the opposite end of the short wire, and capped with a plastic wire nut.  The electrician had already set up a pigtail to ground the switch and receptacle, so I unscrewed the wire nut, added in my new ground, and screwed it back on.  (Wire nuts come in different sizes and are rated for the minimum and maximum number of wires of a given gauge they can handle.  In this case, the one he had used could handle another 12-gauge wire.)

Getting all the wires back into the box was quite a task, and I did have to resort, to some degree, to getting the screws started in the switch and receptacle and using them to push the wires back in a little further.  I think I should have trimmed off some of the wiring the electrician did to make more room, but, oh well, it should be ok.  Cutting back the insulation on the neutral and hot wires just enough to wrap them around the screws ensures that bare wires do not touch each other in the box.

Testing electrical and garage door

I turned the breaker back on, and tested both the corner and ceiling receptacles with a little tester that lights up.  Two amber lights means everything checks out ok.

Ah, but the real test… plugging in the garage door opener and pushing the button on the wall.  Wow, it actually works!  Call your neighbors, alert the media…

Light for the garage

My original plan had been to continue wiring from the ceiling outlet to a fluorescent light that would be controlled from a switch on the wall, probably next to the garage door opener switch, near the front corner.

But after my miserable failure trying to drill down through the back wall when I started this project, I was loathe to try again.  And furthermore, I had barely been able to reach the spot where I tried to drill that hole, I don’t really know how I could possibly drill a hole in the top plate of the side wall right where the roof comes down on top of it.

So, I took the fixture and switch back to Home Depot, and bought a different fixture that hangs down from hooks you put in the ceiling, plugs into a normal receptacle with no wiring required, and, most importantly, is operated by a pull chain.  Not as slick as my original intentions, but, as comedian Kevin Meaney used to sing, “I don’t care, I don’t caaaaaare…”