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Adding recessed cab lights with no attic access

J

jraymond

Member
Location
Traverse City, MI
Occupation
Electrician
Hey guys, hope everyone’s well. I have a customer who wants to add 4 more can lights to a dining room contains one light in the center of the room. I’m going to turn the current light into a recessed can light and pull my switch let’s to my other 4 can lights from that light. There is no attic above, and they don’t want drywall damage so I planned on using my long flex bit to drill through the joists from my center light. We know there is no plumbing running in the joist but my question is: what are some methods of drilling with a flex bit so I don’t accidentally hit a wire that is running in the ceiling? I was thinking of using an ac detector on a stud finder but the ceiling is lath and plaster with drywall on top of it. Any help would be greatly appreciated. Thank you
 
ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
The stud finders I had were not all that reliable. Cable locators used for underground will work but sometimes are too strong.
The extra depth of Lath, Plaster, sheet rock plus the chance of Knob & Tube will make it more fun.

You may luck out and only have a switch leg and neutral coming up from the wall switch.
 
J

jraymond

Member
Location
Traverse City, MI
Occupation
Electrician
thank you for the help. Yeah I think I’ll just go for it. If I’m careful and stay away from the center of the joists to avoid wires, I think I’ll be ok.
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
When I flex drill, I use my instincts and sense of touch. I will often drill the first joist with an auger so I have a larger starting hole for more control and less friction. As soon as the bit pierces the wood, I un-chuck it and gently move it forward and around to see if it hits anything on the way to the next joist.

I keep repeating the same action until I get to the bay I'm aiming for. It usually only takes going through two or three joists between rows of lights. I start my first hole low, very close to the ceiling so my row of holes stays away from the floor above. It sucks to drill holes through a customer's floor.
 
J

jraymond

Member
Location
Traverse City, MI
Occupation
Electrician
LarryFine said:
When I flex drill, I use my instincts and sense of touch. I will often drill the first joist with an auger so I have a larger starting hole for more control and less friction. As soon as the bit pierces the wood, I un-chuck it and gently move it forward and around to see if it hits anything on the way to the next joist.

I keep repeating the same action until I get to the bay I'm aiming for. It usually only takes going through two or three joists between rows of lights. I start my first hole low, very close to the ceiling so my row of holes stays away from the floor above. It sucks to drill holes through a customer's floor.
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Thank you for this. I like your idea of doing a big hole first, and then using the “feel” method. One concern I have is when I’m flex drilling and once I break through, it’s the backside of the joist that could have wires running across and even if I stop drilling once I break through, I could be hitting a wire, if that makes sense. Again, thank you for your response.
 
J

jraymond

Member
Location
Traverse City, MI
Occupation
Electrician
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
jraymond said:
I believe code here is within 1 1/4” from the edge of a stud. And by him saying “very low,” he meant within 1 1/4”
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Studs are within walls, and the building code limit for studs is that holes have to be at least 5/8" from the face of the stud. That is separate from what the electrical code has to say, which is that if the holes is closer than 1-1/4" from the face of the stud, then you need to a nail protector.

For joists in floors/ceiling, the building code requires holes to be 2" clear from the top and bottom of the joist. So "low" should mean the bottom of the hole is just 2" from the bottom of the joist. Which will still be fairly central on a 2x6, but low on a 2x8 or larger.

Cheers, Wayne
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
jraymond said:
One concern I have is when I’m flex drilling and once I break through, it’s the backside of the joist that could have wires running across and even if I stop drilling once I break through, I could be hitting a wire, if that makes sense.
Click to expand...
There is always the risk. What are the alternatives?

I have run wire outside, under siding, and back in again.
 
J

jraymond

Member
Location
Traverse City, MI
Occupation
Electrician
wwhitney said:
Studs are within walls, and the building code limit for studs is that holes have to be at least 5/8" from the face of the stud. That is separate from what the electrical code has to say, which is that if the holes is closer than 1-1/4" from the face of the stud, then you need to a nail protector.

For joists in floors/ceiling, the building code requires holes to be 2" clear from the top and bottom of the joist. So "low" should mean the bottom of the hole is just 2" from the bottom of the joist. Which will still be fairly central on a 2x6, but low on a 2x8 or larger.

Cheers, Wayne
Click to expand...
Well in a 2x6 joist, I’d rather be below 2” than run the risk of drilling through a wire which are typically ran in the center of the joist
 
PaulMmn

PaulMmn

Senior Member
Location
Union, KY, USA
Occupation
EIT - Engineer in Training, Lafayette College
Run from your light along the joist to the side of the room. Pop off the crown molding, drill up to the joist bay, grab the wire and run under the crown molding to the next bay that needs lights. Repeat.
 
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