I am designing a home for my own family. This house would have a full basement. The question: Will the electrical code support using wire ways in the basement, attached to the basement ceiling, to distribute electrical power throughout the home on the main floor, as apposed the traditional running of wire throughout the walls.
Thank you.
Regards,
tachi
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
Replies
tachi
what type of wireways do you wish to use
I am not exactly sure how to answer that question. I work now only in commercial bldgs, so not sure what might be available. But what I had in mind was plastic wireways, large enough to support the volume of wires I need, mounted to the basement ceiling, with an appropriately sized trapeze, under the exterior and interior walls of the main floor. I would do the same thing with the low voltage wiring (telephone, LAN, A/V, HVAC controls, etc.), but in its own wireway, of course.
Regards,
tachitachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
tachi hi
the best thing to do would be get more familiar with residential
wiring. find a lot of info by surfing,library' and speaking to
a legitimate electrical professional. at least a liscened journeyman
familiar with residential.
seems that you are looking to design a commrcial system.
fine for a home if you'd like. more expensive and time consuming though.
probably a little overkill.
but i have always been a fan of well designed building infrastructures.
[wow big word huh!]
take the time to plan well and stick to the plan. it will be the most cost efffffffective method.
berg
Thanks, Berf, for the response. The planning part is precisely what I am trying to do right now. I have lots of time to plan for a house that will probably not get started for 3-4 years from now. Yes, I suspect the 'commercial' approach might add some cost, but also thinking of the ease of making changes in the future. Would rather avoid tearing out portions of walls to get to a wire, for example. With a wireway underneath, every fixture, every outlet is a vertical service up from the basement wireway. You always know where that wire is and how to manage it. I suspect in practice it will not be quite as easy as it sounds in theory! However, good plans and drawings will prevail!!
tachitachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
The basic requirement is that all wire either be cable (IE Romex, MN) or individual wires installed in approved wireways.But there is no requirements about what paths you run the wire/cable.You can run the wire from the basement to each receptacle or switch. You either need run the wire out of one receptacle to the basement and across to the next one and up. Or wire it in a "home run" manor with each one going to a junciton box.The concept is the same whether you use conduit or cable. There are large industrial wire ways that are metal trays. Never had to look at them so I don't know the all the requirements. I suspect that you could use something like that, but WAY $$$$$.I suspect that you are thinking about things like Panduit wiring duct.http://www.panduit.com/products/browse.asp?classid=1006That is not suitable for residential power wiring. But you could use it for LV applications.And you can setup a "wiring area" where you run all romex before braching off to go to a wall.
Your wanting to run EMT with pull boxes below each room. I wouldn't think there would be a problem with it. That sounds like a great plan if you have the time and money. I'd like to do it in my own home one day.
Cable combined with raceways may be a less expensive alternative. Run your raceways and jboxes in the basement but take romex up the walls. In the future you can always access the wiring in the basement and fish new wire up the walls if nessecary.
Also, consider empty raceways to places that you may need to get to in the future: attic, crawl space etc. I've seen some basement finnishes that would have been much easier with a raceway from the panel to the basement for all the new circuits.
Also, chases to run cables and pipes and such floor to floor.
Exactly what I was thinking about! But I had not thought about running the raceways up to the attic. Good point. Lots of room to run more lines, when, and if needed.
Do you know a good source for raceways? I am thinking plastic.
tachi
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
Tachi,
At a Parade of Homes Show last year I saw a house wired in the way that you describe.They used a PVC wireway(I looked but couldn't see a manufacturer's label) the length of the long axis of the house,and then jumped out of it with NM cable into the joist spaces wherever needed.It looked very very nice.They held it off of the outside wall just enough to be able to drill for connectors,with the opening up.By using wireway you aren't weakening the floor joists by boring a bunch of holes in them.
Most of the electricians that I know when trying to do a Cadillac job when building their own homes do use thinwall and then properly locate junction boxes for transitioning to Romex.Just as Gunner said.You do have to think ahead to lay out the circuits correctly.Using wireway would also require forethought since you are limited to 20% fill at any cross section.
I'd plan for an extra course in the basement wall height if you go that way.
Barry
And, again, almost exactly what I had in mind. I often deal with large equipment, but still obviously smaller than a HOUSE! We use plastic raceways with slotted sides. It easy to run wires out wherever you need them. And yes, I had the same picture in mind: running the raceway offset from the outside wall, attached to the ceiling, to give me working room acces to the wall going up to the main floor. I had also planned on 9' ceilings for the basement - yeah, I know that is high, but that gives me lots of room for plumbing, raceways, and I can still put in a drop ceiling in those spaces that I might want to "finish".
This is precisely what I had in mind, but didn't know if the code would allow it. J boxes at the base of walls, and then up to the main floor connection.
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
Wednesday, March 30, 2005 Time: 21:09 Tokyo, Japan
Check this website out. Just found it. http://cableorganizer.com/cable-trays/index.htm The plastic wire duct seems quite pricey at $140 for a 6.5 ft hunk. But the wire trays shown in this link looks like a better solution, anyway.
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
Tachi,
I've often considered the same situation when dreaming... uh designing my own place. I want to be able to easily maintain and replace electrical and plumbing when needed in 20+ years. Maybe I am a little biased from my Navy background.
Some considerations:
Walls are usually stacked, typically with blocking between the lower Top Plate and the upper Bottom Plate.
Fire protection around the wireway.
Esthetics.
Common customs, outre = $$.
Whose labor?
Standardization makes construction easier. <=$$.
So, here's my ideas;
Floor joist blocking: 3 1/2" clear from the top plate on the far side of the wall, 12 1/4" clear from the near side of the wall leaves plenty of room to get a right angle drill into the joist bays. Leaves 1 Black Diamond between blocks (Standardization.) Meets code.
Hang a 2x6 from the near side blocking, DW the top half of the walls walls up to the joists. Nail a 1x6 at the top of the wall over the DW. The 2x and 1x are pre notched for 1x2 let ins. The 1x2s form the bottom of the tray. Align 'em with the joists. Requires the joists be layed to the joist blocking. ie; joist+block, joist+block. Pre notch the tray side pieces and trim the ends to fit when hanging. Production.
Because the joists are standard width, set to a standard spacing, the joist blocks the same, I can cut and notch a bunch of pieces of DW and just put them in the bays production style giving real good fire protection. Only the bottom edge of the joists and the tray bottom 1x2s would not be DW'ed.
Complete all DW, walls and ceilings, and make nice panels to screw to the bottom of the tray. Some molding, and, Voila, I be stylin'.
Shouldn't take more than 40 manhours added to normal construction. Matching soffits around the room. Do the same for plumbing drops.
Speaking of plumbing; The the risers will be in a plumbing wall consisting of 2 @ 2x4 walls set 16 3/4" face to face with the faces flush with the outside edges of adjacent joists. Adding an electrical chase from basement to attic lined with 5/8" fire rated DW leaves 8 1/2" x ?? clear for a vertical wire run.
SamT
Are you planning to run romex in the wire ways, or individual wires? If romex, you will need to work through the derating rules for cases where wires are run in close proximity to each other. But otherwise should be OK. With individual wires you need to either enter conduit or splice to romex, and for that latter case the wireway must be listed as a junction box.
Another approach is to simply run a support board the length of the house and staple the wires to that. This can be a piece of 1x8 or so, or maybe 3/4" plywood cut into strips of the necessary width. If the wires are spaced out enough they don't need derating. The board can be fastened to the "ceiling", the wires stapled on, and then a second board of similar size fastened below (with spacers for air flow) to provide mechanical protection. In all would take 3-4 inches of depth.
Would an inspector have trouble with either of these? In theory they shouldn't, since with a little care all the i's would be dotted and t's crossed, but there are always those inspectors who can't handle change.
You could run something like a 1x8 and use stackers and spacke them aobut 1-2" apart. Get lots of romex in a relatively small area that way.
This brings up a question I have had on my mind. What constitutes "bundling" which will cause the derating requirement. Loose ties over a long run holding four or so runs of NM, putting two runs through a 5/8 hole, or what? I understand if you stuff it in conduit but unless you pack it pretty tight I can not see it being a problem unless you have a pretty maxed out circuit.
Wednesday, March 30, 2005 Time: 18:32 Tokyo, Japan
DanH,
You bring up an interesting point: derating. Now, while I have certainly done a bunch of wiring, including a complete restaurant job and satisfied inspections, I do not claim to be an expert on the code! or the reasons for some of the rules.
I thought the derating was a function of 1) distance, or length of run, 3) wire size relative to load, and 3) the number of line carriers per common neutral or ground wire within a conduit. Wrong?
If the wires, either full jacketed Romex, or 3-strands for each circuit (no grouping) were all simply laid, loosely, in a wire tray, race way, does the derating still apply?
I am thinking of a wire tray that is, say, 6 inches across, and perhaps smaller where appropriate for some of the branches, all hung on a simple trapeze from the basement ceiling.
I happen to be working in a commercial hotel right now with wireways that are about 15" across and carry a huge mass of Romex of varying sizes down the center of the utility corridor. There is not even a cover over the tray which is a slotted metal material that has been painted bright orange, but approximately every meter or so, there is a bracket going across the top to retain the cables.
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
I'm not a "code lawyer", and can't quote all the rules for derating. I do know that if you stack romex more than two deep under staples you have to derate. In general it may have to do with %fill.On a slightly separate point, I'm not sure that loose wires are legal in the slotted plastic tray. I've only see it used for low-voltage wiring around here. I can see it used for romex, but I'm not sure it would meet the protection requirements for loose wires.
One other thing to keep in mind is that the "usual" style of house wiring is really quite efficient. For instance, outlet boxes are "daisy-chained" together, vs each having a run down to some common bus. The common bus approach requires a junction box for each outlet, with three wires coming in to be spliced. Usually more wire, more connections, and more boxes.
Wednesday, March 30, 2005 Time: 18:45 Tokyo, Japan
DanH,
Yes, I had thought about that. Wiring 4 duplex outlets along a wall, for example, or around a room with the wire tray approach would require a box at the outlet, and j-box at the basement ceiling for each outlet. Daisy chain wire would be dropped back into the wire way to go to the next J-box and up to the outlet in the wall, etc. Extra wire, to be sure, and extra J-boxes. But I love the idea of total access, and simplicity.
The other thing I like is the opportunity to run wiring, circuits, in a more logical distribution, rather than the cheapest and easiest. I know everyone has had the delightful opportunity of trying to figure out which circuit breaker goes to that one outlet or light, only to discover it is connected with some circuit on the opposite side of the house. And this only after having turned off damn near every circuit breaker in the box. Some planning and wire ways, I think, can help solve that problem, too.
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
which county do wish to build in...
why the added expense and are you planning to use single strand in a slotted box style with a snap cover or tube or romex in a joist mounted tray???.
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
Wednesday, March 30, 2005 Time: 18:19
I want to build in Southern Colorado - my retirement home. And my daughter and her family want to build the same house, after I finish the design. Probably 3+ years from now. Gives me lots of time to design in all of the details!
Anyway, to answer your question: I was envisioning the slotted box style of raceway. Single strands would be nice, but want to be sure that I can always identify any given wire. Since code allows us to group up some line wires to neutral and ground, there could be savings with that approach. However, I am also aware that I need to be able to control which neutral supplies the return for which line voltage carriers.
So, it might be simpler to stick to 3-wires for each circuit down the wireway and avoid the problem.
Yes, it is probably more expensive, but not significantly, I don't think, in terms of materials. The labor will be mine.
Do you have some concerns about this approach? Lay it on me, please!
tachi
Family in Tucson, business in the Far East, and heart in the Colorado mountains!
you haven't priced race-way... have you...
do what ya want with a tray and build it yurself.. and use Romex... still cheaper...
Heavy gauge steel studs for the tray..
3 runs of THHN is more than 1 run of Romex by about 60% IIRC... don't ferget that you'll be adding a marked increase in the total of LF of wire because of the routing.. WTB - you'll have an increase in labor too...
what have you considered for the drops / branch lines from off of the race-way..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!