I am reposting this question to see if I can get some more opinions of the best way to handle this.

I am installing recessed can in existing ceilings, and need to run wires through joists in some cases, rather than parallel. I have read that I should drill can holes first, then use a flexible drill bit to try and drill holes through joists in order to run the wires to each can. I have a plaster ceiling. Is this the best way, and if so, can you someone give me more specific details how to go about drilling the holes, i.e. what type of drill bit, etc. I fully understand wiring, securing cans, etc. Just getting through the joists in the ceiling is what I don't understand. I would rather not trench out the ceiling and have to replaster.

 

I'm going to move this to the electrical forum, where most of the electricians hang out. You should get more help there.

 

Where are you planning to drill through the rafters? Main floor? Attic?

 

Planning to drill through the joists that would essentially be in an inacessable part of the attic. (Cathedral ceiling)

 

Cathedral ceiling? The spaces between the joists are probably filled with insulation - this is going to be pretty hard to do, I'm waiting to see the suggestions...make sure you are using IC (insulation contact) cans...

 

Is the ceiling constructed as such that you could fish the cables (parallel to the rafters) from an accessible part of the attic to each light location?

 

Flexable bits are sometimes an electricians most valuable friend for old work. They are typically 9/16 or 5/8 drill sized, drill being mounted on a flexible rod maybe 1/8" or a little larger in diameter. They are commonly found in Home Depot or Lowe's stores and are from 40 to over 60 " in length. They have a hole drilled through at each end that will accept a single conductor wire up to about 12 awg. In this way the drill can also be used as a fish tape after the hole is drilled. They tend to 'walk' somewhat and can be aggravating sometimes but the cost is justified if only to drill 1 hole.

 

To answer the question above, there is not insulation where I will have the cans (on the slants of the cathedral ceiling). Imagine a triangle, in my case the insulation is only on the bottom flat part. So with the flex bit, I can drill up to 9/16", to fit 14-2 or 12-2 wire? Please be as specific as possible. Any more suggestions appreciated. Is the flex bit the best way to go?

 

Hmm....deja vu......I just did a install like this on a old house up in a resort near here.....Nightmare job but not because of the ceilings...lol...

We did use a flex bit as described earlier but the position of the recess lights did not mean the bit would actually reach the other possible opening which THEN became a blind feed nightmare.

They are right in that the blade does walk a bit...making it hard to match up two different drilled segments but it can be done......

Because of the lenght and spacing of the lights and so on we ended up putting junction boxes ( plan plastic wing boxes with clean white plate ) in the center of the light pulls to run our wires too......you can't tell they are hardly their and it looks clean and the owner agrees.....

Anyway you do what you gotta do...the spacing of the recesses were more for show than for actual lighting...I tried to tell the guy we needed more but he said it is just for looks....and the height was high enough I bet no one even sees the small plant white cover between the long runs but it did allow us a reference point to drill to and fish to.....

No one likes to cut pull points but as I tell home owners sometimes....it will cost you way more for me to work forever at something than to simply cut and patch.....and get it done...quick and simple.....Sure we fish anywhere we can...down walls and so on...but in some cases you will just eat up a whole day trying to fish accross joists in a ceiling and it just means you have to cut and be done with it....