[fromscratch]

Just bought a house with crawl space under the floor.
Most of the breakers are now connected to romex but there are still 3 breakers that are connected to the old knob and tube.
It looks like one of those knob and tube lines runs the length of the house and there are aprox. 6 outlets spliced off the knob and tube running up into the walls.

I'm thinking of replacing the knob and tube line with 12g romex and putting each of the outlet splices into a junction box with pig tails.

Any reason not to do this?

Thanks

 

[jbfan]

Do you mean a junction box in the crawl space and wire running up to the receptacle?
If so, not a problem.

 

[fromscratch]

Exactly. Six junction boxes in the crawl space, one for each receptacle.

Thanks

 

[Perry401]

Were you intending to leave the knob and tube between the junction boxes and the outlets or were you going to run a new romex cable to each outlet from the new junction boxes?

 

[fromscratch]

Guessing you are going to tell me I have to replace all the wires coming from the receptacles with new romex wire?

I found that 3 of the receptacles have a romex-type wire (There are two copper wires covered in plastic wrapped in a an outer plastic sheath. The outer plastic sheath is a grey to silver color.) leaving the receptacle and spliced into the knob and tube under the house. I was thinking I could probably just use that wire, However I could probably pull new wire.

I haven't looked at the other room yet. If those receptacles have knob and tube running up the wall and I can't pull new wire, is there a reason not to splice with into the knob and tube wire running up the wall?

 

[McSteve]

As long as you don't extend the circuit at all, replacing portions of it with new wiring as you plan to do is fine. I'd make an effort to replace the runs from the receptacles if possible, though.

 

[WillK]

Even better would be if you could pull new romex up to the outlets and have a romex cable going from one outlet to the next and avoid the junction boxes in the crawl space all-together, use your wires that go up to the outlets to pull your new cables through. If the holes through floor and studs are too tight to pull new romex taped to old wire, then tape a string to the old wire, pull that through, then use the string to pull the new cable up.

Junction boxes are an increase in the number of places a loose connection could happen. Also, each junction box means an extra 6" of cable x3. You might not use much more wire, and you'll probably have a little less work in the crawlspace which is usually not that much fun.