Running conduit to update 80 yo electric
Hi all,
I am updating the electric in my 80 year old house prior to adding insulation to the exterior walls. The house is a balloon-frame 2- story with a brick veneer, full basement and a partial attic. The current electric wiring is 2 conductor solid wire BX with cloth-covered rubber insulation. The electrical insulation is crumbly in many places. The BX snakes everywhere, so I figure I should update it while the walls are empty.
I will run conduit up from the basement to the first floor to feed the outlets and wall sconces. In some cases, it might be best to daisy chain the run along the perimeter of basement. My question is how to do that. All the exterior wall boxes are singles, so I do not have 2 down-facing knock-outs to run conduit in and out of. I could use 4×4 boxes on the bottom of the floor joists, and run shepard’s hook bends (aka goose-neck) up to each outlet or sconce box. So far I have only run conduit from boxes in the basement that happen to be near where I am going, but I do not have the same convenience everywhere.
I could also use ideas on how to run conduit or greenfield between the ceiling fixtures and the wall switches. I had hoped to pull the new stuff on the tail of the old, but my experience with ripping what I have so far suggests that this will not work. I would like to minimize the demolition of old plaster wherever I can.
Thanks,
Scott
Replies
Whew! You like to work, huh? If your ever near Tennessee, I'm sure I could find plenty for you. If it must be pipe, than buy some extra. You can measure and re-measure all you want, but you will still find yourself scrapping quite a few peices. Go by your nearest electrical supply house for a pocket bender book, I am just assuming that you haven't done much of it before.
We have a guy bending smoke detector conduit on half of a six floor condo building (well, I guess its some sort of time share hotel). All of the smoke detectors are tied together in each unit, and then tied to the hallway and I guess to the fire alarms panelboard after that. Every bit of it is spec'd in EMT. He's been bending pipe for a long time, and he still gets quite a bit of scrap peices. There are formulas and take-ups that you need to know, and it has been a long time since I've done any significant bending.
So far, so good. The last 2 shepherd's hooks I bent wasted only about 3" at each end. I bend them a bit long, place them and mark where they hit the box, remove and cut to length. None of the pocket books I've seen show take-up or anything about bending these.
and none of the books will it's all OJT
because the benders really aren't meant to bend goosenecks or shepherds hooks since the bend extends past the sidewalls of the bender shoe and can kink and flatten the pipe... years back there were some inspectors in Dupage County that wouldn't allow them because some folks would go crazy trying to use it everywhere, end up with more than 360º of bend between openings and probably a few kinks to boot, which makes pulling wire a real pain or impossible don't forget to ream the pipe !.
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OJT?
If you use the bender's hook on the stuff already bent, then it will not kink the EMT. If you try to hook around the straight part past the bend, then it will kink. I've made half circles to make 'S' hooks to help carry sheets of plywood.
DuPage county IL? That's where I'm at.
so you now how to apply foot pressure ? ....... very goodyeah Illinois so what do you do when you're not tearing your house apart ?.
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....... On the Job Training.
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I was going to ask if you where crazy.
Then I checked your area.
Below each receptacle mount a T conduit body and run a single conduit up to the box.
But don't splice in the conduit body. Run the 2 condutors up to the box and then back down to go to the next one.
William the Geezer, the sequel to Billy the Kid - Shoe
I was going to ask if you where crazyLOL but it would be cheaper to just use boxes instead of Ts ..... give him future access to the homeruns.
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Make your pipe runs vertical ... that is, feed from one box to the next one above it. The, exit the top of the box, make a 90, cross over, and come down into the top of the next box.
Where you have to drill across a series of studs, it's best to start at an outside corner, and feed the pipe through ALL of them, letting the pipe tell you where to drill the next hole. Make sure the pipe is perfectly level and square with the wall, or you'll get in trouble as your errors add up.
The best way to drill between studs is using an impact driver and the Irwin Speedbor Max bits.
If your local town will allow you to run MC .... I THINK that's what you mean when you say "BX" ... life will be much easier. Fishing wires through steel flex is not easy. Be sure to run an extra wire to light fixtures.
You might as well cut to the chase, and simply remove ALL the plaster. It will be easier, and a better 'fix,' if you just start over.
Yep, you wont get very far with all of that nasty plaster in the way. I don't see steel conduit in houses built after like 1950. I don't see houses that vintage without some sort of fire blocking in the stud bays either. Its hard enough to fish wires in them, much less try to feed pipe.
I'd rather do a tricky conduit job than a tricky conduit job and a bunch of drywall and/or plaster work on top of it. I'm just not going to bust out all the walls to rewire. I may be stuck with some of that to wire the wall switch for the ceiling outlets, but where there is another way, I'll do it.
I may add outlets on the outside wall of the second floor (none there now), fed from the first floor. In this case, I will feed up 2 straight pieces, each half the distance to between the first and second floor boxes. and use a 3" hole saw to cut an access hole at the top of where the first piece ends up as placed. Through that hole, I can place a coupler to join with the next piece. This way I can do it with just 3 holes - the second floor box, an access hole at the second floor fire stop (to drill for the conduit) and around the middle to join the pieces.