DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   Adding a new circuit breaker (

ksl420 05-22-2006 10:31 AM

Adding a new circuit breaker
I am going to be remodeling my bathroom and am planning on installing heated floor for the bathroom floor. I am only using 15 sq. ft of the heated floor stuff which uses 12 watts per sqaure foot. The bathroom circuit is combined with another room in my house that I run my computer from, i am worried about overloading this circuit and would like to add another specifically for the heated floor. What is the easiest way to go about this, my breaker box is located outside along the back of the house, do I simply turn off all power to the house, take the cover off of the panel feed the new line up into the attic then wire it up? I guess I am not sure how feeding the line up to the attic will work out, is this usually a pain or does it go pretty easy, is anyone familiar with this type of setup, being the breaker box is on the back of the house? Any advice, tips would be great.


MinConst 05-22-2006 11:33 AM

Hi Kris,
By the phrasing of your question I would have to say this might be something you may want to leave to a professional. DIY is great is many projects but electricity is something you should not deal with unless you are experienced in the field.

ksl420 05-22-2006 01:57 PM

To pay someone $100 for an hours worth of work is not an option for me, I plan I doing this myself, anyhelp anyone can give would be appreciated.


IvoryRing 05-22-2006 03:03 PM

Lets see... playing devils advocate on some of the things you need to know/take into consideration when going on your own that a properly liscensed electrician would bring to the table for whatever they would charge you...

Are you aware that when you flip the main breaker on your panel, you still have live (and very much deadly) power in your panel? Are you sure you know where existing lines (power and water) are in the attic and wall spaces involved? Do your local codes require firestop in bored holes in the top plate, or other interesting things that might not be mentioned in 'wire it yourself' books? Is the panel surface mounted or recessed? Do you have access to the attic above the panel? Does this flooring require GFCI (if it is plugin, rather than hardwired, it certainly will if the outlet for it is in the bathroom, but there may be other constraints that would require it as well)? Is your existing circuit GFCI? If no, do you know if your local inspector will require you to make the existing circuit GFCI once you start with electrical work in the bathroom?

I'm slowly working on a rewiring of my house, and it is non-trivial to do. If you are careful, methodical, stick with NEC and local codes as a minimum and understand electricity, it is something a DIY can do.

In my case, I'm saving a little bit of money (not a whole lot), and getting a house wired up the way that I can understand it, as well as doing a few things 'above the code' that a cut-rate electrician wouldn't bother with. It is worth it to me... but if I was starting from scratch and wanted just one circuit - well, it's a lot of time invested to the point of doing it right for just one.

Some specific tips, since you asked:

1.) Make sure you don't push your panel to more breakers than it is rated for. If you don't know, find it on the label. the breakers that are 'two skinny ones in one opening' count as two breakers for this purpose. Generally speaking it is not terribly useful to screw down a second wire into an existing breaker.
2.) Mark both ends of the wire, either with an indelible marker, or a professional labelmaker (I've found the cheapie label makers suck - the labels don't last long when wrapped around a cable, they peel off) - at the bathroom end, mark it with the word 'upstream' and the breaker number. At the breaker end, mark it with 'bathroom floor panel' or something like that.
3.) At both ends, pay attention to the colors of your wire... black for hot (goes to the brass screw if you are putting in an outlet - and to the breaker itself in the panel), white for neutral (silver screw if you are going to an outlet - at the panel end, if you are using a GFCI, then it goes to the neutral terminal on the breaker, otherwise it goes to the neutral bar, which will be where all the other white wires screw down - and don't forget it should go in its own screw hole), and bare or green for 'ground' (does NOT just get pushed into the ground, or wired up just 'somewhere', it goes to the green screw on an outlet, and if you have a metal box, it also goes to a green screw screwed into the box itself - at the panel it goes to the grounding bar, where all the other bare or green wires are screwed down; also in its own screw hole)
4.) Make sure your connections are screwed down tightly.
5.) Using wire nuts anywhere? pretwist them (same direction as tightening a screw), make sure you are using the right nut for the size and number of wires you have, and screw down the wire nut as tight as you can.

ksl420 05-22-2006 04:10 PM

Thanks for the info,
I have been in the attic, I know where the lines are running as I just retiled the shower surround, and had to tear down most of the walls.
The flooring will be hardwired to a programmable thermostat that has a built in GFCI
I am very aware the panel will still have power as the main line is always on and I would have to have the electric company turn that off.
The original bathroom outlet did not have a GFCI on it but I did swap that with a GFCI recepticle, one question I have is if the thermostat has a built in GFCI does the circuit breaker also need to be GFCI?

The panel is mounted to the outside of the house, not recessed, that is why I am curious about getting the wire into the attic, should I just be able to push the wire through and go up there and see it sticking out of the insulation? Or is there much more to it? I do not have direct access to above the panel, in the attic

The firestop, I am not sure but would be a good thing to do regardless of whether it is required by code. So I will plan to do that

Again thanks for the info,

MinConst 05-22-2006 05:41 PM


Originally Posted by ksl420
To pay someone $100 for an hours worth of work is not an option for me, I plan I doing this myself, anyhelp anyone can give would be appreciated.


I understand your thinking on this. But conside this. You save $50.00 on this by doing it yourself. And you have a problem. What would you guess that might cost in the way of money or life?

If you could see what we as contractors see you might understand the reason for my response.

Be safe.

joed 05-22-2006 05:55 PM

The current code requires the bathroom receptacle to be a 20 amp GFCI. It can only serve the bathroom not other rooms(computer etc.). The lights in the bathroom can be on a circuit with other rooms however.

Speedy Petey 05-22-2006 07:21 PM

What Min & Joe said.

A) You are renovating this bath so it must be brought up to current code.

B) You are installing electric radiant heat. This is NOT cheap stuff, yet you cannot afford to have it installed correctly?
I hope you do something special with the $100 you might save.

It amazes me how people's perspective can be skewed.

Sparky Joe 05-22-2006 09:01 PM

Crawling in the attic is always a pain, do it in the morning, and if your roof slopes down on the side where your panel is you'll have a real tough time getting into that corner. And remember when you turn your panel off there are still live parts in it, actually the most potetially explosive parts that are in it ever.

IvoryRing 05-23-2006 10:25 AM


I will second what Joe said about the roof over the panel - that's my situation in my garage over the back wall (the ceiling of the garage actually slopes down in the back) - and it is a big pain. I ended up cutting a big rectanglular hole in the sheetrock on the wall near the ceiling and installing a 6"x9" access panel just so I had a starting point to drill UP through the top plate. Once I got through the top plate, I had another 3 feet of 'fish it through, getting snagged constantly on roofing nails and insulation' before I even got to the point where I could see it from the attic crawlspace.

Another thing you need to be aware of - if the panel is surface mounted, as you indicate, then you have two choices that I know of: 1.) run through one of the side/top/bottom knockouts and then into the side of the house, or 2.) run through the back. Unless you already have conduit in the back, it just isn't going to be practical to go that way, which means you likely will need to go though the side/top/bottom. So - since it is outside (i.e. wet location), that means you are going to need to use connectors and a cable that is rated for wet locations & sunlight exposure, then penetrate the skin of your house (in a way that won't introduce all kinds of new problems with water entering), and go up. Ignoring for the moment how you are going to get into the attic, the transition from the panel (outside) to inside is going to be a hassle. Once you get inside the wall, you are going to have to figure out how to get the cable into the attic without access from above.

All times are GMT -5. The time now is 10:50 AM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1