type of conduit for string lights

Questions on how we spend our money and our time - consumer goods and services, home and vehicle, leisure and recreational activities
Post Reply
Mjar
Posts: 47
Joined: Wed May 23, 2018 5:18 pm

type of conduit for string lights

Post by Mjar » Mon Jun 18, 2018 2:03 pm

I have put up string lights that zig zags across on my deck by affixing conduit pipe vertically to act as the support posts. I have used 2 half inch (1/2”) pipes at 4ft in length combined together with a coupler to make the post just about 8ft tall. I did this because the big box store does not sell 8 footers. And I have the option of buying the 10 footers but I don’t want to cut it down to 8ft nor do I want the post to be up 10 feet above the deck floor. I installed the post like I described and when I put the string lights up the top 4ft of the post angled in because of the pulling force to make it as tight of a line on the string line as possible as slack would allow someone to bump their heads on the lights if they were 6feet or tall in some areas (near the posts it’s at 8 feet so no worries there).

My question is it looks secure with the angled but I was wondering if 10 conduit will be better to prevent the angling of the pipe. I am going to reconfigure the lights so instead of zig zagging I will go around the perimeter where having slack won’t be an issue because no one can walk under it so the pressure won’t be as much on each post angling it less. Since I am going to reconfigure I have to take the lights down, so I thought if I am going to take the lights down that would be my chance to replace the 2 four footers coupled to one long 10foot conduit. I just want the coupler to snap or the top 4 feet to come off the coupler as it is already angling. The couple and the conduit is threaded so it’s on tight. Also should I then go wit the 3/4" instead of the 1/2" diameter conduit if I go 10ft to make it more rigid?

Thanks in advance!

User avatar
Pajamas
Posts: 5777
Joined: Sun Jun 03, 2012 6:32 pm

Re: type of conduit for string lights

Post by Pajamas » Mon Jun 18, 2018 2:17 pm

The 10 foot pipe sounds like a good idea. The lights will also look better if they have more slack and you want the lights well above anyone's head as it is disturbing to walk under them if they are within say 6 or 8 inches from the head, especially for visitors who aren't used to them. You didn't say why you didn't want the pipes to be 10 feet above the deck floor and I did question if there is a particular reason for it.

The 3/4 inch pipe should be much more rigid than the 1/2 inch pipe and should more than offset the effect of the additional length on rigidity.

tev9876
Posts: 99
Joined: Thu Sep 14, 2017 9:12 am

Re: type of conduit for string lights

Post by tev9876 » Mon Jun 18, 2018 2:24 pm

What are you actually mounting the conduit to? Is the conduit bending or is the entire length remaining straight but angled? It sounds like you are using rigid metal conduit based on the threading. That should be rather strong as it is not designed to be bent like EMT conduit, but if you are not securing a good portion of the height against something solid the slightest amount of horizontal force at the end of an eight foot lever is going to put considerable stress on it. A good bump might rip it out of the deck if you are only securing it at the bottom.

Mjar
Posts: 47
Joined: Wed May 23, 2018 5:18 pm

Re: type of conduit for string lights

Post by Mjar » Mon Jun 18, 2018 2:58 pm

The bottom 4 foot is connected to the 4x4 post with the conduit hangers and that is rock solid, it is angling just at the coupler. The hangers are at the bottom and the top of the 4x4 so that bottom 4t is plumb

I don't want the 10ftrs initially because i hate cutting any metal for some reason I can never do it cleanly and felt the 10ft length would be too tall, but now I am re-thinking it and just still put the lights at 8ft or so and have the additional 2 feet just rise above. I know it will angle somewhat but I feel its a bit much, its about 4-5 inches from plumb from the coupler to the top of the top 4ft section. The top 4ft section is only mounted at the coupler to the bottom section. So the pipe is still straight but angled from the coupler. The reason I went to 1/2" instead of 3/4 was cost.

The angling I can get less when I go to the perimeter layout instead of the zig zag layout since at each post the string is pulling in the same general direction to the house vs in the perimeter layout the inbound string will pull in a completely different angle than the outbound string. Right now the angle between the inbound and the outbound string at each pole is about 40 or so degrees, in the new layout it be 90 degrees or so.

User avatar
Pajamas
Posts: 5777
Joined: Sun Jun 03, 2012 6:32 pm

Re: type of conduit for string lights

Post by Pajamas » Mon Jun 18, 2018 3:08 pm

I would be concerned about enough weight and tension in electrical wires to pull a four foot section of 1/2 inch pipe at an 8 or 10 degree angle even though you didn't state the distance between the pipes. The tension in the wires would still be an issue with single 3/4 inch pipes. Might be a problem if there is high wind and especially with branches or other debris in high wind. There will also be sagging over time. You might consider using cabling and attaching the light strings to them, winding the strings around the cabling, etc.

I'm certainly not recommending this site as a store but for the information on it. You can also click through to see an example of cable suspension hardware.

http://www.lightsforalloccasions.com/p- ... ights.aspx

Mjar
Posts: 47
Joined: Wed May 23, 2018 5:18 pm

Re: type of conduit for string lights

Post by Mjar » Mon Jun 18, 2018 3:21 pm

Pajamas wrote:
Mon Jun 18, 2018 3:08 pm
I would be concerned about enough weight and tension in electrical wires to pull a four foot section of 1/2 inch pipe at an 8 or 10 degree angle even though you didn't state the distance between the pipes. The tension in the wires would still be an issue with single 3/4 inch pipes. Might be a problem if there is high wind and especially with branches or other debris in high wind. There will also be sagging over time. You might consider using cabling and attaching the light strings to them, winding the strings around the cabling, etc.

I'm certainly not recommending this site as a store but for the information on it. You can also click through to see an example of cable suspension hardware.

http://www.lightsforalloccasions.com/p- ... ights.aspx
I have suspension wires made for string lights so the string lights are not under any real pressure or stress, it is all on the suspension wires. Distance between each "turn" or connection point is about 16 feet.

User avatar
Pajamas
Posts: 5777
Joined: Sun Jun 03, 2012 6:32 pm

Re: type of conduit for string lights

Post by Pajamas » Mon Jun 18, 2018 3:23 pm

Then if you use 3/4 inch ten foot pipes securely anchored at the base and at four feet or so from the base it should be fine.

neilpilot
Posts: 1702
Joined: Fri Dec 04, 2015 1:46 pm
Location: Memphis area

Re: type of conduit for string lights

Post by neilpilot » Mon Jun 18, 2018 3:31 pm

I just looked at this thread, and everyone is talking about "pipe". Just to be clear, isn't the OP using conduit or pipe? I ask this because from my perspective conduit, weather metal plastic or fiber, is tubing. Pipe is much more rigid.

So OP are you using pipe?

sixty40
Posts: 184
Joined: Sat Dec 06, 2014 11:53 am

Re: type of conduit for string lights

Post by sixty40 » Tue Jun 19, 2018 2:19 am

People use the conduit term genetically, but most likely you are using EMT (electrical metallic tubing) which is just thin wall conduit. They do not have threaded couplings or connectors, only compression or set screw, and both will bend at the joint. If you really have threaded fittings then you have either rigid steel conduit or IMC, which is thicker wall. Conduit is not meant for that type of tension, but if you can, you should use 3/4 or 1” or larger so you can pull it tight, especially if you are using EMT. Also the conduit can get electrified if there is nick in the wire or something, do make sure everything is grounded properly.

Mjar
Posts: 47
Joined: Wed May 23, 2018 5:18 pm

Re: type of conduit for string lights

Post by Mjar » Tue Jun 19, 2018 4:47 pm

I am using pipe, 1/2" threaded, its is thicker than the conduit, its rigid. I was using them interchangeably when I should not have.

Post Reply