Hello,

I want to run some conduit in the attic space of my new workshop to carry low voltage lines (coax and Cat6a). I was hoping to use schedule 40 pvc for its cost and ease of use, but I keep finding contradictory info on if it's safe/allowed.

Any information or advise would be greatly appreciated.

Thank you.

"Smurf" (blue PVC) is acceptable, as is PVC schedule 40.

It is not for plenum use. (but you are very unlikely to run it in any plenum area in a home.)

PVC conduit has thinner walls than pipe (thus cheaper) and is usually gray in color.

I don't know what the code is in Oregon but if you get up there and your electrical isn't in a conduit(Pvc or metal) then I think you're ok with using it.

I found this which mentions pvc schedule 40 and non-metallic conduit:http://www.oregon.gov/bcd/licensing/Documents/md-study-guides/mdisc-studyguide-chapter6.pdf

I imagine you could go to any electrical supply store (not HD) and they could tell you for sure.

ETA: This link: http://www.oregon.gov/bcd/laws...rs/305_Table_1-E.pdf
mentions schedule 80 but has removed the reference to crawl spaces. It also mentions "where necessary". And does not distinguish high voltage fro low voltage wiring.

Check out page 9.

When we run those cables here most of the time we don't use any conduit so I don't know why any conduit if wanted would be a problem.

when in doubt, call your AHJ. I typically don't put any of that stuff in conduit in my house, either, but not sure if that's up to code or not.

Thank you all for the replies so far. I want to use the conduit in case I ever need to add, replace or upgrade any cables. The ceiling is 18.5' high and will have no access opening.

The attic is not a plenum space.

My concern after reading the various sites was temperature. The attic is vented along the full 70' of ridge, but has no fans. Even in the PNW, we do get occasional summer tips over 100 degrees, so I wouldn't be surprised if the attic got over 120.

I trust in the people of SigForum, and if you all think I am good to go with the PVC, then I got some conduit to run.

Thank you again.

quote:

I want to use the conduit in case I ever need to add, replace or upgrade any cables

In this case, I highly advise leaving a pull string i the conduit, tied off at both ends. Flexible conduit would be preferred... no 90 degree turns to negotiate.

Those temps won't hurt your cables, they're spec'd for higher than that.

You are fine with PVC. Temps in your attic will not affect the pipe unless you have a fire.

AFAIK coax and Cat cable can be run any way you want in a home. So putting them in PVC pipe should not be an issue.

The flexible stuff is a lot easier to work with than Sched. 40. Definitely go with a pull string, it is easy to suck one through an empty conduit with a vacuum cleaner, not so much once it is full of cables, although a cable can become a pull cord in a pinch.

I had planned to include a pull string in each conduit for future use, but thank you for the reminder.

So you think 1" Smurf tube would be better than 1" sch 40?

Schedule 40 is schedule 40, whether it is grey (conduit) or white (water pipe). The advantage of the white is that it comes in 20’ lengths, while the grey conduit is typically only seen in 10’ lengths. The disadvantage of the white is that it really sucks when you go back years later and cut open what you think is a water line and cut a bunch of wires that you really didn’t intend to cut. I don’t believe that cat6 or coax are subject to the electrical code, so there is likely not a code problem to using whatever you want.

I ran some 2” “hose” conduit on the ranch for phone and camera lines. I forget what type of plastic it was. It was hard, similar to the yellow gas lines they put in, and it was magic as it came in 1000’ rolls, so it involved a lot less coupling.

From past experience, I will say that if you have a relatively inaccessible area, I’d put a lot more conduits in than you think you’ll ever need. It is orders of magnitude easier to pull another cable in an empty conduit than it is to add another cable in a conduit with existing wires in it, even with a pull rope, wire, or tape. The problem is that things seem to get all wrapped up as they pull through the conduit.

Another thing, 2500# pull tape is magic stuff. Unlike a lot of contractors that use it as a consumable item, I use it as a tool. I typically blow a pull string in using an air compressor and leave that there (consumable) until it is time to pull wire. Then I pull the tape in with the string (no tension so the string won’t cut the pipe) and use the tape to pull the wire. When done, I roll the tape back up for reuse.

Last thing: If you’re gluing pipe, you’ll be happier if you only put glue on the pipe, not in the bell. That way any excess glue will end up outside, not inside where you are going to want to pull wires.

This message has been edited. Last edited by: slosig,

I planned to run 1 or 2 extra empty pipes between my main boxes.

I'm hoping I've over done the wiring so I won't need much more in the next 20 years.

Thank you for the tip on glue.

Can't figure out why you would need conduit for low voltage and coax but if that's what you want to do then just about anything will do.

quote:

Originally posted by Blume9mm:
Can't figure out why you would need conduit for low voltage and coax but if that's what you want to do then just about anything will do.

Winner!

Makes zero sense to run it in conduit. Can't think of any reason to do it. Actually I thought of one reason, physical protection, if you are storing stuff up there, it wouldn't be a bad idea. Why do you think you should do it in this manner?

If you are worried about expansion in the future run smurf tube to most likely points, but the ones where you are running wires to now, just used standard construction methods.

I have 3 wall enclosures in the building for various equipment. The conduit is to be installed between them so I can run new/ additional wires if needed in the future.

Most of the wire is installed more traditionally, without conduit. I just wanted easier runs between these points if needed down the road.

quote:

Originally posted by Blume9mm:
Can't figure out why you would need conduit for low voltage and coax but if that's what you want to do then just about anything will do.

I may have misunderstood the description, but a valid reason for conduit may be access. If you have good access to the space while building, but no access at all later, having unused conduits could be very useful.

You are correct. Right now everything is accessible, but once the insulation and Drywall is installed, the only way to run a new wire would be to cut holes in both the ceiling drywall and insulation.

Just trying to look towards the future.

quote:

Originally posted by silverspyder1996:
You are correct. Right now everything is accessible, but once the insulation and Drywall is installed, the only way to run a new wire would be to cut holes in both the ceiling drywall and insulation.

Just trying to look towards the future.

Don't use conduit for stuff that is accessible now. Add a conduit for future with a pull string if you are planning to close it up. Insulating at attic isn't 'closed up', IMO. If you can walk in the attic, it will be easier to run wire than pull through conduit. If you can't access the attic, run a couple extra CAT6 lines - there's not much you can't do with CAT6 if you try hard enough.
Full conduit is damn near useless for adding, unless you pull all the old wiring out to pull the new.

Conduit won't protect from ambient temperature. Wire insulation is usually rated at 90-105 CELSIUS. If your attic gets over 170*F, you have more problems than coax failing.