Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 11-18-2008, 02:47 PM   #1
Newbie
 
Join Date: Sep 2008
Posts: 14
Rewards Points: 10
Default

expanding knob & tube wiring


I'm remodeling my bathroom and there is a single switch operating a ceiling light. I would like to add a ceiling fan on an adjacent switch. Since it's knob & tube, their is only a hot wire going to the existing switch and then up to the ceiling light. From the light it travels back to the neutral line in the attic. Seems like I can add an additional switch by splicing (wire nut) into the hot wire before the original switch and connect it to the new switch (I'll install a dual swicth electrical box). Then I'll run a hot wire from the new switch to the fan and from the fan run a line to the existing light and splice into the existing line leaving the light (acting as the neutral). Is my logic correct??

jadrma is offline   Reply With Quote
Old 11-18-2008, 02:59 PM   #2
Member
 
Join Date: Jul 2008
Location: Iowa
Posts: 1,543
Rewards Points: 1,000
Default

expanding knob & tube wiring


Quote:
Originally Posted by jadrma View Post
I'm remodeling my bathroom and there is a single switch operating a ceiling light. I would like to add a ceiling fan on an adjacent switch. Since it's knob & tube, their is only a hot wire going to the existing switch and then up to the ceiling light. From the light it travels back to the neutral line in the attic. Seems like I can add an additional switch by splicing (wire nut) into the hot wire before the original switch and connect it to the new switch (I'll install a dual swicth electrical box). Then I'll run a hot wire from the new switch to the fan and from the fan run a line to the existing light and splice into the existing line leaving the light (acting as the neutral). Is my logic correct??
You cannot extend ungrounded circuits. Is the line with the neutral in the attic grounded?

rgsgww is offline   Reply With Quote
Old 11-18-2008, 03:44 PM   #3
Newbie
 
Join Date: Sep 2008
Posts: 14
Rewards Points: 10
Default

expanding knob & tube wiring


Yes, the neutral runs in the attic are grounded at the 100amp Service Panel.
jadrma is offline   Reply With Quote
Old 11-18-2008, 03:52 PM   #4
Member
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 8,134
Rewards Points: 3,062
Blog Entries: 4
Default

expanding knob & tube wiring


Since all neutral wires are grounded at the panel let's ask that question in a different manner. Are there three wires including ground at the light fixture?

Last edited by joed; 11-18-2008 at 06:18 PM.
joed is online now   Reply With Quote
Old 11-18-2008, 04:18 PM   #5
Newbie
 
Join Date: Sep 2008
Posts: 14
Rewards Points: 10
Default

expanding knob & tube wiring


No...this is knob and tube so there is only a single wire (hot) to the wall switch which then travels to the light fixture. That same wire then travels to the attic and ties into the parent neutral line which runs back to the grounded service panel. Only a single wire makes up the circuit.

Last edited by jadrma; 11-18-2008 at 04:19 PM. Reason: Removed distorted drawing
jadrma is offline   Reply With Quote
Old 11-18-2008, 04:26 PM   #6
Member
 
Join Date: Jul 2008
Location: Iowa
Posts: 1,543
Rewards Points: 1,000
Default

expanding knob & tube wiring


Quote:
Originally Posted by jadrma View Post
No...this is knob and tube so there is only a single wire (hot) to the wall switch which then travels to the light fixture. That same wire then travels to the attic and ties into the parent neutral line which runs back to the grounded service panel. Only a single wire makes up the circuit.


You have two options, install 14/2 with ground to the main (15 amp) or 12/2 with ground (20 amp) or not install the fixture at all.

If you decide to run wire you must read up your local code amendments...they may require certain methods (like conduit and type ac cable).
rgsgww is offline   Reply With Quote
Old 11-18-2008, 06:01 PM   #7
Newbie
 
Join Date: Sep 2008
Posts: 14
Rewards Points: 10
Default

expanding knob & tube wiring


Thanks for your help. I think I'll go ahead and get a bid on replacing the 100amp panel with 200amp and replacing all of the old knob & tube wiring.
jadrma is offline   Reply With Quote
Old 11-19-2008, 09:47 AM   #8
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,970
Rewards Points: 2,036
Default

expanding knob & tube wiring


(While replacing all knob and tube wiring is recommended everywhere, in most places this is not mandatory even if you upgrade the panel. So you might choose to have a professional upgrade the panel while you replace wiring yourself at your convenience.

As you need new wiring work at the bathroom light switch, you might as well, if you do it yourself, rewire the bathroom light and decommission that part of the knob and tube wiring at the same time you install the fan. Instead of having both the new cable feed for the fan and the old K&T feed for the light entering the same switch box.)

Last edited by AllanJ; 11-19-2008 at 09:59 AM.
AllanJ is offline   Reply With Quote
Old 11-19-2008, 10:21 AM   #9
Member
 
bradnailer's Avatar
 
Join Date: Nov 2008
Posts: 256
Rewards Points: 250
Default

expanding knob & tube wiring


I feel your pain. I renovated a 100 year old house with knob and tube wiring. The first thing I did was drop in a 200 amp panel then gradually rewired the entire house as I renovated rooms.
bradnailer is offline   Reply With Quote
Old 11-19-2008, 11:26 AM   #10
Newbie
 
Join Date: Sep 2008
Posts: 14
Rewards Points: 10
Default

expanding knob & tube wiring


How do I change out my K&T wiring room by room? Is there a way to transition to 12-2 or 14-2 by splicing into the old wiring or do you have to make the change all the way back to the Service Panel thereby replacing the entire circuit and everything it operates?
jadrma is offline   Reply With Quote
Old 11-19-2008, 12:37 PM   #11
Member
 
Join Date: Jul 2008
Location: Iowa
Posts: 1,543
Rewards Points: 1,000
Default

expanding knob & tube wiring


Quote:
Originally Posted by jadrma View Post
How do I change out my K&T wiring room by room? Is there a way to transition to 12-2 or 14-2 by splicing into the old wiring or do you have to make the change all the way back to the Service Panel thereby replacing the entire circuit and everything it operates?

You would have to rip it all out and run new. I would recommend not doing it yourself if you do not know much about electrical (multiwire branch circuits, ampacity, etc.)
rgsgww is offline   Reply With Quote
Old 11-19-2008, 05:05 PM   #12
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,970
Rewards Points: 2,036
Default

expanding knob & tube wiring


You start re-doing each circuit by running the new cable from the breaker box. You may follow the route of the K&T hot wire from one receptacle to the next but you should add more receptacles if needed to meet code. (Typically 11 feet apart or so that a 6 foot cord from a lamp standing anywhere against the wall can run along the wall and reach a receptacle without crossing a doorway.) You may decide that two new circuits are needed to cover all the rooms that one circuit served years ago. If the K&T neutral goes back to the panel via another route, you do not need to continue running cable from the last receptacle that way.

There are special rules for circuiting kitchen, laundry and bathroom receptacles, including having separate circuits of 20 amps each.
AllanJ is offline   Reply With Quote
Old 11-19-2008, 05:27 PM   #13
Newbie
 
Join Date: Oct 2008
Posts: 11
Rewards Points: 10
Default

expanding knob & tube wiring


get 3 quotes from licenced electricians on replacing the panel and as many circuits that you can access without punching dozens of holes in the walls. i would also consider a 125 amp panel as it is cheaper than a 200 amp which you probably don't need anyway. we did this in our previous house and got rid of all but 2 W&K circuits.

mattedfred is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Knob and tube wiring PAULYBOY Electrical 1 03-28-2007 07:20 PM
Knob & Tube wiring - How concerned should we be? hotdiggitydog Electrical 6 04-11-2006 08:52 PM
Installing new lighting on knob and tube wiring drichard Electrical 1 03-05-2006 03:55 PM
How safe is knob and tube wiring? jackdp Electrical 8 10-29-2005 11:50 AM
Cost of replacing old knob ant tube wiring in house bikerboy337 Electrical 3 03-26-2005 09:50 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.