atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring New Construction Residential Cable Install

First off, this is really a cool forum. You don't come by forums full of helpful people like this too often.

I did some reading/searching and got most of my questions answered. However, I still have a few more.

I am currently having a house built, and I work in a small IT shop where I do a little of everything. So as you can imagine I am super excited to wire my house. I would like to run my "plan" past some of you to get some feedback.

So here it goes...

Cat6 patchpanel, and rg6 coax patchpanal in the basement. Cat6, RG6 cable from there to all wallplates. The first floor rooms I intend to simply drill through the bottom plate of the wall run the wires from the basement through the hole up into the wall, and to the keystone wallplate.

For the second floor I am having them install a 3" PVC pipe from the basement to the attic space.
So for the second floor I would run from the panel to the pipe in the basement, up the pipe into the attic, to the top of the wall where the jack is, drill through the top plate of the wall, run the wire down the wall to the wallplate.

I have read the national electric code 70, but to be honest it is a little hard to understand. I guess I am most concerned that the wiring I am going to be doing is going to pass code inspection.

The Cat6 is CMR, and the Coax is CMX. I am using the "low-voltage boxes"

Is the method/path I am choosing code acceptable? I think power wire needs to be run horizontally through the wall. (not that i am doing any)

Should the pipe be of any special type? like actual electical conduit, or will white pvc pipe be acceptable? At this point I don't know what they are planning on using.

Maybe I have nothing to worry about as is a single family dwelling???

As you can tell I am in need of some serious help. Thanks in advance...

Thanks very much for the compliments about our forum and welcome aboard. You'll get plenty of assistance here.

I agree that reading NFPA70 is like reading the Bible in reverse. Fortunately, your situation is not subject to a lot of scrutiny as long as you do a clean job and don't act like a fool.

Let's get the legal stuff out of the way first. Any type of cable that is rated CMX is limited in length to 50 feet and only for use in residences. Will this be caught by an inspector? I doubt it, but I'd think that you can get RG6 with a CMR rating for the same price. Buy quad-shield RG6 if it doesn't break the bank

White PVC pipe is technically only approved for DWV (Drain/Waste/Vent) applications when used indoors. Any connecting conduits for your wiring should be contained within gray PVC electrical conduit. Schedule 40 is the standard and will be fine for your application. I really doubt that you would encounter any resistance for using either type for just a simple wiring chase.

Vertical penetrations between floors or even through a sole/top plate require fire stopping in most places. Usually, this is done by using red caulk. Because of this, I prefer to spend an extra two bucks per outlet and use a piece of 3/4" ENT ("Smurf tube"). Fire stop that thing all day long, yet you will still have a clear channel to add/remove wires from above or below. ENT is sold in 10' lengths at most home centers, so leave the excess in the attic, especially for outlets on outside walls. That way you won't have to crawl so far into the corners of the attic to get to the end. You (or a future installer) will appreciate that extra three feet sticking up through the insulation.

Always, always run an empty conduit between floors as you have planned. 3" might be overkill, but why not? An inspector will likely insist that you seal both ends with fire stopping caulk to prevent drafts. In my area, all that is expected is typical foam spray to block vertical draft.

CAT6 is overkill, but if that floats your boat and you have deep pockets, then go for it. You are only adding expense and labor for yourself by using it. If you follow the concept of using tubing/conduit to open all possible pathways in the walls, then you can rest at ease. You can pull next year's technology in with a simple trip into the attic.

My personal attitude about wiring houses for voice/data/video is to pipe them, not to wire them. Throw in some empties on as many walls as you deem practical. The extra few bucks might make you day when it comes time to move furniture.

Welcome to the forum, Briggs.

The conduit you use should be approved for electrical use. White PVC is for plumbing. You can find grey PVC that is made for electrical/ communications work.

"Low voltage boxes" is a little vague. If you are talking about something like this , note that they cannot be used in fire rated walls.

Using cat6 for voice is completely pointless. If you want cat6 for data everywhere, then that's good, but cat3 is more than adequate for any voice needs. If it were my home, I'd run one cat3, one cat6, and one RG6 (voice, data, video) to most receptacles, in 3/4" ENT.

I'd have to look at the 08 NEC to find the section(s), but I'm fairly certain that you cannot run power and communications cabling through the same stud/joist/plate holes or conduit. I'd also surmise that using CMX rated cable is not acceptable when penetrating multiple floors.

If your attic is big enough to ever be a finished attic, you may want to consider running all cable down into the basement rather than in the attic, first floor wall placement permitting.

Installing a 3" vertical conduit in a home may be tricky - I'm guessing at some point it will run through one or more 2x4" top/bottom plates, which are 3.5" wide. A 3" conduit is 3.5" wide. If the walls through which it will pass are all 2x6 or larger, then you should be okay (you'd still need nailplates by code unless the conduit is EMT). A 3" conduit to service the v/d/v needs of just the second floor of a home seems like overkill to me.

All vertical penetrations as well as those through fire rated walls need to have appropriate firestopping.

This should go without saying, but all cable runs should be homerun from the jacks to the basement.

Jack

I don't know how many runs, but a keystone patch panel could handle both the ethernet and catv connectivity.

Had I waited another 10 minutes, I could have just typed "What Ed wrote".

Jack

Good advice from Ed and Jack. I would add further comments to the coax installation. NEC Art 820 covers CATV, satellite and antenna wiring in buildings. For some reason the listings for coax are a little different than the rest of the low voltage cables. Here is the poop:

__________________________________________________________________________________________________

Summary - 1999 NEC Article 820 - Cable Requirements Within Buildings.


Notes: When the length of cable within the building does not exceed 50 feet (15.2 m) and the cable enters the building from outside and is terminated at a grounding block (inside the building), no cable requirements apply to the entry cable within the building. However, the ground block shall be located as close to the point of entry as practicable.


CATVP (Plenum)

Type CATVP, Plenum Cable shall be used in ducts, plenums and other spaces used for Environmental air.

Note: Types CATVP, CATVR or CATVX cables installed in compliance NEC Section 300-22 of the NEC.


CATVR (Riser)

Type CATVR, Riser cable shall be used in vertical shafts and from floor to floor in multistory buildings.

Note 1: In one-family and two-family buildings, CATV or CATVX cables may be used.

Note 2: In commercial and multifamily buildings, CATV or CATVX cables may be used if installed in metallic conduit or noncombustible tubing or if the vertical shaft is fireproof with fire stops between floors.


CATV (V-Rated)

Type CATV cable shall be suitable for general purpose use with the exception of Plenums and Risers.


CATVX (X-Rated)

Type CATVX cable, less than 0.375 inch in diameter shall be limited to use in residential dwellings (not commercial buildings) or where the cable is non-concealed and the internal length of the cable is less than ten feet.

__________________________________________________________________________________________________

In addition, cable can be had with a CL2 listing also, if required by the AHJ.

One problem with this is that the cable may indeed be listed as above but it's not indicated on the jacket or even on the reel. Hopefully the cable model number is and also hopefully the inspector or AHJ will accept a copy of the manufacturer's specs for that cable model number that indicates the listing. To further complicate things there is coax with absolutely nothing printed on the jacket. I would assume that such cable meets the CATVX requirements but an inspector or AHJ may disagree and say it's only for use outside or limited to 50 feet within the building.

From the above though you can see that type CATVX is acceptable for a single family residence and assuming it's printed on the jacket you are OK there.

One final word- the coax patch panel. Don't bother because it's not done that way. And don't bother terminating the cables either. Ingress and leakage are big problems these days and no cable guy is going to trust a DIY installation. He's only going to cut your handi-work off and install new fittings. So my advice is to leave your cables at each jack location and the other ends in the basement. Be sure and leave more than adequate excess at each end in case the cable gets damaged or has to be moved. That's all you should do, let the cable guy handle the rest. Blank up your jack locations if you must to pass inspection until jacks get installed.

-Hal

Well, I knew I was going to get a response but this is great! Thanks all..

So now for the clarification I need..

Fletcher: "Low voltage boxes" is a little vague. If you are talking about something like this, note that they cannot be used in fire rated walls.

That is exactly what I am using. How do I know if my wall is "fire rated"? This is a basic two story house.

Fletcher: (you'd still need nailplates by code unless the conduit is EMT).

I think the builder will charge me a fee if I were to request a change to emt. What is a nailplate? How does it work, and will it inhibit being able to run wire from top to bottom?

hbiss: Thanks for the CATV info.

The good news is that I looked again at my RG6 and it indeed is CMR, printed right on the cable. SAme with the Cat6

EV606: Talks about red caulk, and firestoping smurf tube.

Does it have to be "red", or will normal white silicon work? How exactly do you firestop smurf tube. Do you mean caulk around where the tube goes through the top plate not the actual tube? If I don't use the smurf tube, I can simply caulk where the cable goes through the top plate?

Does "great stuff" count as firestop?

My builder has indicated on the plans for 3" pvc, caulked at the floors and capped on both ends.

Will caulking the chase in that attic and basement count as firestop?

I will have to take some pics as it gets done to show what I am doing.

Firecaulking is usually red, not always. This is what you need to look for. It's available at HD in the caulk section, probably around $13 a tube.

A nailplate protects the cable/conduit from nails/screws that are installed during construction. You only need these if the cable or conduit is closer than 1.25" to the stud edge. If you are centered in the top/bottom plates and keep the cable in the middle of the stud, you won't need them. Nail plates are metal rectangles of various sizes (2x4 up to 2x12") with 4 bent- in "teeth" on the corners. Installing them is simple: hammer them into the studs/plates where (if) the cable is too close to the edge.

How do you know if a wall is fire rated? Look at the blueprints. I don't do a lot of residential work, but I would imagine that kitchen and exterior walls are fire rated on both sides, as well as the garage wall, and any wall that has a fireplace. Local building codes may also list other walls as needing to be fire rated. Those LV nail on plates only come with a 1/2" or 5/8" face, and can't legally be used in a double sheetrocked wall: the box face can't be recessed more than 1/4", and has to be flush with the finished wall if the wall surface is flammable (like wooden paneling).

I do hotel work where almost everything is fire rated, so I always use closed-back boxes. They are not much more expensive than open back ones, and are better not just for fire, but for reduced sound transmission.

The problem with 3" PVC in a 2x4 is that you have to completely cut away all the wood to get the conduit in. If the walls are not perfectly aligned, the conduit will wind up slightly outside of the stud bays, which will be a problem come drywall time. Cutting out the entire top/bottom plate is also not good from a structural standpoint, and I'd bet that it's against building code. 2 or 3 1.5" EMT conduits would present none of these problems. This is not a major change order.

The other problem with a 3" pipe is that, unless it is very full, you would need firestop sticks to seal it. Great Stuff is a draft seal and, like all polyurethane foams, is highly flammable. It is not a firestop. Here's an article on firestop.

Jack

Fire wall ratings are not an issue in a single-family residence, even on walls with an attached garage. Standard boxes, rings or whatever you want to use are fine.

Nail plates are always required, regardless of conduit or cable type if there is less than 1.25" of clearance from the stud face.

Good to hear about the firewall ratings...

So now I can use the orange boxs. Good thing b/c I allready bought them.

All of the wall the 3" will run through have been changed to 2x6 construction to accomadate for the diameter.

How do you keep a bare coax or cat6 cable at least 1.25" from the stud face? Stud face being the face of the stud the drywall is screwed to? That seams impossible when the wire is dangling from the topplate all the way to the box.

Same questions goes if I were to use the smurf tube?

To coincide with ED comment my prints don't say anything about firerating walls.