20' aluminum light pole what size Sono tube

Hello all
I have to install a 20' aluminum light pole. What size Sono tube would I need. The pole is square. I will have one fixture on top. I know you are suppose to have this engineered out but I was hoping to get a rough idea on what I'm looking at for size. I was thinking maybe a 18" tube 6' long. 4' in the ground and two above. Maybe it needs to be longer? Any help would be great.
thanks
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Using your guesstimate, I would make one change: 6' tube, 5'​ in the ground.

Don't forget to make a hole in the tube for the PVC stub-out. ;)
 

nickelec

Senior Member
Location
US
By the precast footings , I have a friend doing alot of these on a job right now the precast are easy to install and sometimes cheaper

Sent from my SM-G965U using Tapatalk
 

Cow

Senior Member
Location
Eastern Oregon
Hello all
I have to install a 20' aluminum light pole. What size Sono tube would I need. The pole is square. I will have one fixture on top. I know you are suppose to have this engineered out but I was hoping to get a rough idea on what I'm looking at for size. I was thinking maybe a 18" tube 6' long. 4' in the ground and two above. Maybe it needs to be longer? Any help would be great.
thanks
I'm doing a job with 25' poles. Base is 24" diameter, 30" above ground, 48" below ground.

For what it's worth.
 

GoldDigger

Moderator
Staff member
Although you can possibly come up with a general conservative answer, I would have to say that the engineered answer will depend on the characteristics of the soil or other substrate and the likely wind loading on the pole.
 

Fulthrotl

~~Please excuse the mess. Sig under construction~~
Hello all
I have to install a 20' aluminum light pole. What size Sono tube would I need. The pole is square. I will have one fixture on top. I know you are suppose to have this engineered out but I was hoping to get a rough idea on what I'm looking at for size. I was thinking maybe a 18" tube 6' long. 4' in the ground and two above. Maybe it needs to be longer? Any help would be great.
thanks
permitted? how you gonna get this signed off without a stamped drawing?

last poles i did required a certified inspector for the pour, and a concrete sample
he took with him. all working off a stamped approved drawing.

YMMV.
 

dkidd

Senior Member
Location
here
Occupation
e
You need information on the E.P.A. of the fixture(s) and the design wind speed.
 

sameguy

Senior Member
Location
New York
Maybe throw some rebar in.
At the last lighting job we did it became obvious prefab is now the way to go. No drilling use a backhoe, no pour, no base bolt problems, base was smooth,...
 

kwired

Electron manager
Location
NE Nebraska
Although you can possibly come up with a general conservative answer, I would have to say that the engineered answer will depend on the characteristics of the soil or other substrate and the likely wind loading on the pole.
:thumbsup:

By the precast footings , I have a friend doing alot of these on a job right now the precast are easy to install and sometimes cheaper

Sent from my SM-G965U using Tapatalk
Seems to me a poured in place footing fills all the voids. Precast would mean you need to compact soil around it, as well as under it if you excavated too deep, or you have more risk of movement later. Not really any different than setting wood poles in direct contact with soil. Not saying it won't work, but probably has advantages as well as disadvantages.
 
Wow
Thanks for all the suggestions. I do have a permit for this. The city does not require a stamped set of prints for this pole. I had not thought about a precast base. I will have to look into that. To be safe though I'm getting a engineer to figure out what we need for sure. I agree that it depends on the soil and that part I'm not really sure what we are going to need. I will reply back with the answer from the engineer to see what he says. thanks for all the great suggestion.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Many pole manufucturer's have "per-engineered" base designs in their technical literature. Of course they are based on a specific set of conditions that may or may not apply to your installation.
 

MNSparky

Senior Member
Location
Minneapolis, MN
I just did my first job with direct buried poles. They were 5” round aluminum, 20’ above grade and 4’ below, with a double bullhorn and two 300w flood lights for a sports field. The pole supplier did all the calcs for the soil type, I just needed backfill with coarse gravel or concrete. I went concrete. They went really well, I was impressed. A lot cheaper than getting footings poured as well.
 

kwired

Electron manager
Location
NE Nebraska
I just did my first job with direct buried poles. They were 5” round aluminum, 20’ above grade and 4’ below, with a double bullhorn and two 300w flood lights for a sports field. The pole supplier did all the calcs for the soil type, I just needed backfill with coarse gravel or concrete. I went concrete. They went really well, I was impressed. A lot cheaper than getting footings poured as well.
What is the significant difference if you filled the hole with concrete anyway? Only 20' pole (above grade) doesn't need anything too special of a footing if it just has a couple luminaires on it.
 

MNSparky

Senior Member
Location
Minneapolis, MN
The difference in my eyes is big cost savings. In the past, I’ve hired a concrete guy to make the rebar cages, pour the footings and then hired a crane to set the poles. In this case, we dug a hole 4’ deep, was able to set the poles by hand with three guys fairly easily since they are aluminum and we are just dropping them in a hole, not up on bolts (no crane) and we mixed 5 bags of concrete for each pole ourselves in a wheelbarrow (no concrete contractor, the concrete just needs to be heavy, not any particular strength). It was a little extra work for us, but we saved I’m guessing $3500 in subs.

The reason I went this direction in the first place is we needed to put these poles out in a field with no road access. We couldn’t have cranes or concrete trucks drive on the sports fields as they’d destroy them. The poles were light enough for two guys to easily carry them the several hundred feet to the locations.
 

kwired

Electron manager
Location
NE Nebraska
The difference in my eyes is big cost savings. In the past, I’ve hired a concrete guy to make the rebar cages, pour the footings and then hired a crane to set the poles. In this case, we dug a hole 4’ deep, was able to set the poles by hand with three guys fairly easily since they are aluminum and we are just dropping them in a hole, not up on bolts (no crane) and we mixed 5 bags of concrete for each pole ourselves in a wheelbarrow (no concrete contractor, the concrete just needs to be heavy, not any particular strength). It was a little extra work for us, but we saved I’m guessing $3500 in subs.

The reason I went this direction in the first place is we needed to put these poles out in a field with no road access. We couldn’t have cranes or concrete trucks drive on the sports fields as they’d destroy them. The poles were light enough for two guys to easily carry them the several hundred feet to the locations.
I see what you are getting at now. It doesn't have a concrete base, just concrete fill around it. Really good job of tamping soil could be just as good.
 
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