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wiring over roof

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Joined: Mar 24 2003

I will be adding various wiring (120v ac, speaker, ethernet, and coax for tv...this is strictly a question of where and how as the decision has been made). Anyway, I believe that building code dictates that 120v must reside within appropriate conduit (hopefully there is flat conduit...). Because of this, I would likely be required to contract an electrician.

Things are less certain with respect to speaker, ethernet, and coax or other similar low current/voltage wiring. The plan is to get a roof replacement and so would like to install as much cabling as possible (within reason of course) and was wondering what methods have previously been employed? The idea is to install as much as possible to account for future additions and not have to penetrate the new roof. Such items include sound systems for each room, network access, telephone wiring, etc. Does anyone have any thoughts or experiences?


Joined: Mar 21 2003

Check with you local building and safety department.

We live in Sunnyvale and last year we remodeled our kitchen. The remodel included new 115v AC wiring on the roof to move some circuits and add more lights. They allowed the new wiring to be run like the old: Secured to the decking then covered with secured galvanized metal angle.

Your jurisdiction may be different.

By the way, we found the Sunnyvale Building and Safety people to be very easy to deal with and the only issues we had with inspections were clearly our own in-experience and/or oversights. (We acted as our own contractor and did our own carpentry, electrical and plumbing.)

Joined: Jan 4 2004

Hello Fred,
We have done many roof retrofits in Eichlers; as complex as adding 78 recessed lights, 20 surface mounted fixtures, A/V; low voltage cabling (phones and coax), plumbing, radiant heat supply lines and skylights, to simpler projects, such as adding surface mounted fixtures in bedrooms and exhaust fans in bathrooms, and about every degree in between.
If you are going to re-roof, that is the opportune time to address any or all of these issues; we have done all of the things mentioned above without impacting the appearance of the roof with protrusions and bumps; from the outside it appears to be a "normal" Eichler roof.
It is important to know that this type of project is very linear on time, sequencing subs, inspections, etc. and is a bit tricky in terms of project management. It is very do able, as we have done about 8 without any trouble.
Also, unfortunately, any work of this sort has to involve opening of some walls down below, and requires careful planning on the part of every trade involved. The result is never having to deal with the electrical conduit rotting in the dirt, as so many Eichler owners have experienced
due to the wiring methods used in the period of original construction.
If you want to Email me directly, I'd be happy to give you more info on this subject, as there are many details that I could post here that don't apply to your situation. Unfortuately, I can't offer my services in Walnut Creek :( (the logistics are bad running a project requiring this level of attention from where we are located), but I'm always happy to give advice, and you may call me as well (my ad is in this site: Renaissance Man Construction) Also, there is a simple way run conduit for future construction as well. Good luck!


Joined: Mar 2 2004

Protecting the live electrical wiring is required. The idea is to prevent a nail, drill bit etc. from contacting or damaging the 110 or 220 volt wiring. This is done by securing angle metal of the appropriate thickness over the wiring. It's hard to find the metal that matches the original. After many inquiries from owners, electricians and contractors, we finally had some made and currently have about 1,000 feet of the shallow U-channel type, if you need it. I don't think you are required to protect co-ax, alarm, phone, computer, door-bell, intercom wiring etc.
It's great to bury the wiring. The sun takes a real toll on exposed wiring. When we install a foam roof, we usually aren't required to remove the old tar-papers (just clean and secure it). After the surface is cleaned, we have found some good methods to secure the wiring so you get a good looking roof.

Joined: Jan 4 2004

Randy is correct, you are not required to protect coax, phone lines, CAT 5,
Speaker Wire, Alarm wiring, or any conductor carrying 60VDC/AC or less;
However it is a good idea to install these in some sort of raceway or conduit to:
A. prevent damage (it'd be nice if it works after you install it)
B. allow for upgrading to any new updates in tech-such as new conductors for any type of transmission of data (remember dial-up modems-
now cable modems and DSL are around, who knows what will be the standard in 10 years before it is time to re-roof)
C. Allow for any other changes such as adding A/V processors etc.

As far as wiring methods and the installation of romex or (NM) type conductors, while the NEC does not specifically disallow its' use on top of the tongue and groove roof planks, every building inspector that I have discussed this topic maintains (and correctly so) that it must have some protection to prevent damage. Because I and my employess can run conduit about as fast as protected NM conductors, we generally run conduit. However, the channel Randy was talking about is a pretty cool idea as well. Also, the holes for the ceiling boxes are 3"-3 1/4" and we use 1/1/2" round mud rings for 4" square metal boxes. I hope some of this info was helpful.


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