ECN Forum
Posted By: Redsy Fence as support ? - 06/25/03 01:03 PM
Would it be acceptable to secure a PVC conduit run to the bottom of a chain link fence? Huge roots & rock would impede digging a trench.
Has anyone ever used a fence as a support structure?
Posted By: resqcapt19 Re: Fence as support ? - 06/25/03 03:24 PM
Redsy,
I've seen fences used for conduit support. It works well with metallic conduit, but the spacing of the fence posts is normally too far apart for PVC conduit where supports are required every 3' for 1" and smaller and every 5' for 1 1/4" through 2". You will also need to install expansion joints if the calculated change in lenght is over 1/4". An outside run of PVC here in Illinois that is exposed to direct sunlight will may require two expansion fittings every 100'.
Don
Posted By: GEO Re: Fence as support ? - 06/25/03 03:27 PM
have used top of chain link fence, by running conduit,this was coated to match fence(green)worked well and is still in existance. GEO
Posted By: Bill Addiss Re: Fence as support ? - 06/25/03 03:53 PM
I think strapping conduit near the bottom of a chain link fence would be putting the conduit where it could very likely be damaged by people stepping on it.

For argument's sake could pressure treated 4x4s or RR Ties be considered as support laid on the ground between posts? (the conduit would be strapped to it at appropriate intervals and to the posts) It would help protect the conduit in the spans between posts. Would that be acceptable to everyone?

Bill

[This message has been edited by Bill Addiss (edited 06-25-2003).]
Posted By: Redsy Re: Fence as support ? - 06/25/03 04:00 PM
Don, GEO thanks for your input.

The pipe would be installed at ground level, so "support" per se, is not an issue.
I'm also interested in attachment method to the fence, which would actually be used to "fasten" the conduit in order to keep it from moving.
Posted By: Redsy Re: Fence as support ? - 06/26/03 08:36 PM
Bill,
Didn't mean to slight you by omitting your name. You must have been posting while I was writing.
I am considering the PT 4x4s. I guess they would need to be anchored w/ rebar spikes.
Posted By: Bill Addiss Re: Fence as support ? - 06/26/03 09:12 PM
Redsy,

No problem here. [Linked Image] That happens to me a lot because sometimes it may take me 20 min to get a post up for whatever reason.

If the 4x4 thing sounds good maybe you could staple the chain link to them (4x4s) with Galvanized staples?

Do our Inspectors have any comment on that?

Bill

[This message has been edited by Bill Addiss (edited 06-26-2003).]
Posted By: Redsy Re: Fence as support ? - 06/27/03 11:53 AM
Our traffic lighting, and highway sign conduits are usually fastened to the main support pole with metal banding.
As far as attaching to the bottom of the fence, would UV resistant ty-raps be acceptable.
Can 110.3 be cited in either or both cases described above?
Posted By: Bjarney Re: Fence as support ? - 06/27/03 12:12 PM
Redsy — Might you be able to use Aerosol/"worm" clamps to secure the raceway? They seem fairly corrosion resistant and not too pricey.
Posted By: resqcapt19 Re: Fence as support ? - 06/28/03 09:08 PM
For the expansion joint(s) to work, whatever type of fastening that is used must allow lengthwise movement of the PVC.
Don
© ECN Electrical Forums