ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
New tool
by JoeTestingEngr - 10/22/20 12:58 AM
Where is Everyone?
by Bill Addiss - 10/17/20 07:04 PM
Beyond Belief
by gfretwell - 09/27/20 12:03 AM
Questioning the electrical norms
by LongRunner - 09/23/20 06:38 AM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 13 guests, and 16 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Tree Light #77504 06/18/01 06:23 AM
Joined: Oct 2000
Posts: 5,389
sparky Offline OP
How can a light be properly installed on a tree, assuming it is still growing?


[Linked Image]

2017 / 2014 NEC & Related Books and Study Guides
Re: Tree Light #77505 06/18/01 07:27 AM
Joined: Mar 2001
Posts: 2,056
Redsy Offline
Are you using low-voltage lighting? If so, either Hadco or Seagull(I don't remember which, maybe both)make an accessory to mount their tree lights. It's like a bracket with a stretchable strap that wraps around the tree. I guess as the tree grows(a slow process anyway), the strap stretches.
As far as line voltage, maybe stainless steel screws. A marine supply store probably has them. If not, McMaster-Carr does.

Re: Tree Light #77506 06/18/01 08:56 AM
Joined: May 2001
Posts: 176
WARREN1 Offline
There appears to be two factors to be considered here. One is the upward growth of the tree, and second is the outward or ring growth of the tree.
The upward growth can be accounted for by allowing an unstapled loop in the cable, which would allow the cable to "stretch" in an upward fashion as the tree grows taller.
The increasing diameter of the tree can be allowed for by installing the conduit riser several inches from the tree trunk as trees grow very slowly in diameter. Refer to 300-5 (a) and (d).
Anyway, a new owner will probably have you take it all out and install something else in its place.

Re: Tree Light #77507 06/18/01 10:27 AM
Joined: Oct 2000
Posts: 3,961
Bill Addiss Offline

I thought that trees only grow from the top, so the loop would be unnecessary. I've always sleeved UF in Pvc conduit strapped to the tree with a piece of flexible at the top that goes to the box. I'd usually try to run the conduit up the back side of the tree (to be unseen) and come around the front with the flex to the fixture.


Re: Tree Light #77508 06/18/01 06:13 PM
Joined: Oct 2000
Posts: 5,389
sparky Offline OP
I usually will shy away from a 'live-vegetaion' install, but you know how it is, the customer is king!!!
I will probably run UF( only due to line V) and provide a few expansion joints. Will the avearge oak outgrow a few joints in my carear??

[Linked Image]

Re: Tree Light #77509 06/18/01 10:36 PM
Joined: Oct 2000
Posts: 3,961
Bill Addiss Offline

I don't think the tree grows "up" so you don't have to worry about that. You haven't seen any tree swings up in the stratosphere have you? [Linked Image] The UF inside the PVC will have a little flexibility because the cable itself is not fastened to the tree. Some slack up near the fixture would be good though. It's likely that the tree would grow aroung anything that's fastened to it over time.


Re: Tree Light #77510 06/19/01 05:10 PM
>I thought that trees only grow from the top
Tree trunks do not stretch vertically. You are correct that they gain height by growing new growth out the top.

Re: Tree Light #77511 01/28/06 11:36 PM
Joined: Aug 2005
Posts: 214
Elviscat Offline
I like the idea of the expansion joints in the PVC, I've never installed a tree light but I did see one where the electrician came up the "back" (side facing neighbor's property) of the tree with PVC then wrapped around the tree to the light. There was a good 2" between the box and conduit where the tree's growth had snapped the TA in the light box right off.

Re: Tree Light #77512 01/29/06 03:54 PM
Joined: Oct 2004
Posts: 132
mhulbert Offline
I did a tree install last year. I had PVC underground, used a 2' piece of flex at the base of the tree, emerging from the ground, and then coupled that to 15' of Rigid going up the tree. This went into a WP box. I used #10x 1 1/2" Stainless "Sheet Metal" screws. fasten the rigid. I did not fully tighten them to the tree, and informed the ownere that they would probably have to loosen the screws every couple of years, or the pipe would soon dissapear. I painted everything flat black, so you can't see it unless you're within 5' of it.

The only crummy part was trying to bend a 15' length of rigid to match the subtle bends of the tree trunk.


Re: Tree Light #77513 02/09/06 05:21 PM
Joined: Sep 2004
Posts: 6
Mills Offline
New Member
The “loosen the screws every coupla years” approach is probably the best compromise. I had to fix a bunch of these where the tree growth had destroyed the original installation. I used long SS lags and stood off the PVC a couple of inches from the trunk. I’ll go back and sell the owner some maintenance during a slow period.

I was careful to seal all openings, because the worst part was that the fixtures were full of ants that bite or sting when disturbed. [Ouch!]


2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Nicholson Ga
Posts: 34
Joined: June 2006
Show All Member Profiles 
Top Posters(30 Days)
BigB 3
Popular Topics(Views)
270,722 Are you busy
204,962 Re: Forum
193,068 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3