light pole bases / foundations question

[Electron_Sam78]

I'm going to be installing 5 light pole bases which will be a first for me. The specs say 5' in the ground with rebar cage but that's about it. How do you guys make the rebar cage? Sections tied together to make a square then several of those tied to vertical sections to make a 3D rectangle? I saw one post where the horizontals were bent in circles with verticle bars tied to it to make it a cylinder. I guess you would do that with a torch? Also I planned on putting my sono tube all the way down into the ground the 5 feet but I saw an older post where some disagreed with that. Also can fiber reinforced concrete take the place of rebar? I can make the decision even though the specs say rebar. The specs are borrowed from another contractor that put poles on this property previously.

 

[sameguy]

If spec is rebar use rebar, round square, no matter tie pole base bolts to rebar; tube in or out of ground no matter.
Just get the crete in befor it rains.
No spec or drawing of what is required? follow what the other guy put in.
How tall are the lights? 5' deep should be ~20' pole.

 

[cowboyjwc]

If spec is rebar use rebar, round square, no matter tie pole base bolts to rebar; tube in or out of ground no matter.
Just get the crete in befor it rains.
No spec or drawing of what is required? follow what the other guy put in.
How tall are the lights? 5' deep should be ~20' pole.

Be careful what you install, here we require an engineers stamp on light pole bases.

Jobs like this is where I lose all of my sympathy for EC's screaming about guys doing electrical work. Leave the concrete work to the concrete contractors.

 

[sandking]

Typically there is or has been a structural design for the pole base. It depends on hieght, weight and style of the pole in addition to the wind rating of the location its in. I have done tons of light poles and the concrete contractor will build the specified rebar and install into the sono-tube that they install as well. The sono-tube is usually recessed in the ground just far enough to where you wont see the end of it. No need to have it all the way down. Once the sono-tube and rebar is installed, then you install your conduit then they pour the concrete. I just stub the conduit out of the area then tie it in after concrete is done. The diameter and length of anchor bolts are to be specified and supplied by the light pole manufacturer.

 

[weressl]

I'm going to be installing 5 light pole bases which will be a first for me. The specs say 5' in the ground with rebar cage but that's about it. How do you guys make the rebar cage? Sections tied together to make a square then several of those tied to vertical sections to make a 3D rectangle? I saw one post where the horizontals were bent in circles with verticle bars tied to it to make it a cylinder. I guess you would do that with a torch? Also I planned on putting my sono tube all the way down into the ground the 5 feet but I saw an older post where some disagreed with that. Also can fiber reinforced concrete take the place of rebar? I can make the decision even though the specs say rebar. The specs are borrowed from another contractor that put poles on this property previously.

It is a good practice to embed the anchor bolts into the base and have standoff nuts to keep the base of the metal pole from sitting on the concrete, leaving a 1-2" air-gap. It avoids corrosion of the base and the pole to fall over.

 

[iwire]

It is a good practice to embed the anchor bolts into the base and have standoff nuts to keep the base of the metal pole from sitting on the concrete, leaving a 1-2" air-gap. It avoids corrosion of the base and the pole to fall over.

It is also a bitch to level the pole if you don't use double nuts ......... but of course I have never seen anyone try to just crank a site pole tight to the concrete, that would be dumb.

Typical spec is double nuts, level the pole and grout under the pole leaving a nice chamfer to let the water run off.

 

[ptonsparky]

If you can find someone to do the bases have them do it. We have done it in the past but have seen a few put together. None have fallen yet so they must be good, right? What will work in good undisturbed soil won't be worth diddly in the sand just a few miles South of here.

We helped set a small wind gen a few weeks ago and the persons responsible for that base used fiber instead of a large rebar cage. They still had a small cage around the base bolts.

Google light pole bases or something similar.

 

[stevenje]

Jobs like this is where I lose all of my sympathy for EC's screaming about guys doing electrical work. Leave the concrete work to the concrete contractors.

I couldn't agree with you more. They have the tools, the technique and the knowledge. Do what you do best and sub the rest.

 

[Electron_Sam78]

The specs I have are for 30' poles. I'm putting in 20'. Like I said in the first post I'm borrowing the specs from another contractor since he just put some poles on nearly this exact site. We have no inspection authority we have to answer to we just need them not to be blown over. I figure if I use specs for the 30' poles I should be good. I will have help from people that have installed these before I just want to have an idea of what I'm doing beforehand. So what I have so far is:

Dig hole with auger,
build rebar frame,
use plywood pattern to position anchor bolts,
attach anchor bolts to rebar,
install rebar frame in hole (use something to keep it off the bottom of hole),
install conduit stub-ups and tape or cap,
install section of sono-tube above ground with reinforcing wood frame/stakes to keep it in place,
pour concrete,
keep anchot bolts level,
wait for curing,
remove sono tube, plywood,
install pole & wire

 

[sandking]

Dig hole with auger,
build rebar frame,
use plywood pattern to position anchor bolts,
attach anchor bolts to rebar,
install rebar frame in hole (use something to keep it off the bottom of hole),
install conduit stub-ups and tape or cap,
install section of sono-tube above ground with reinforcing wood frame/stakes to keep it in place,
pour concrete,
keep anchot bolts level,
wait for curing,
remove sono tube, plywood,
install pole & wire

Dig hole
set sono-tube staked off with 2x4's
build rebar and drop in tube
hang rebar cage from top of tube via steel stake bridge and tie wire
install conduit stubs
build plywood template for anchor bolts and assemble with 4" of exposed bolts
pour concrete
install anchor bolts into wet concrete and square off
pull wire before you set the pole

This is the norm here in CA, may be different in other places, but I have never seen the anchor bolts attached to the rebar, instead they are at least 24" long with a "L" on the end buried in the high strength concrete.
Here is a generic sample....

 

[ksmith846]

VE IDEA

VE IDEA

You would be better off $$ wise to quote 5 concrete light poles.
They are cheaper to buy than the typical metal pole and base setup. Also they come with wind load calculations and are less $$ to set.

I would get a quote for 5 concrete poles and offer 60% of the savings to the owner as a deduct keeping the other 40% and get my poles done in 1/2 the time.

just my 2 cents.....

 

[Hv&Lv]

There are places around that will make a base for you. Your time is more valuable somewhere else than waiting for concrete to dry...
How much do you stand to lose if one base is wrong and has to be redone?
I would suggest looking into some premanufactured bases. We pour our own light bases, but we do 50-100 a year.
A steel yard bends our rebar to the correct circumference, and it is aggravating making sure the steel stays where it is supposed to. Once it lays against the sonotube, the whole structure is ruined. Will it be hidden under the dirt? Sure, but wrong is wrong. We use chairs to hold the steel in the right place, and remove them once the concrete is at the top of the steel and wont move. Of course, there is also the problem of anchor bolts, Do you preset them? or float them in? I have done some both ways...

http://www.darnallconcrete.com/light pole main.htm

http://www.concretebuildingsupply.com/index.php?page_id=159

 

[sameguy]

errr umm ground rod and wire, We buy prefabs and pour our own too. Depends on site conditions and qty.. Normally we have a spec. to work off of.
In parking lots you will need reveal and the sono tube is all the way into the hole not just for the above ground part.
Do not let the sono tube get too wet or it will blow out (rain).
You can pull wire before the pour; also its no big deal to pour concrete use a vibrator, make chamfer, trowel.

 

[hillbilly1]

Be careful what you install, here we require an engineers stamp on light pole bases.

Jobs like this is where I lose all of my sympathy for EC's screaming about guys doing electrical work. Leave the concrete work to the concrete contractors.

I had one plan review department kick back the engineered prints, they wanted straight anchor bolts instead of the traditional "L" type, they claimed they were stronger, and would not pull out like the "L" type. Don't know if it was true, but the engineers re-drawed the prints. The supply house had to order them custom, as nobody stocked them. 40' poles, two head.

 

[weressl]

It is also a bitch to level the pole if you don't use double nuts ......... but of course I have never seen anyone try to just crank a site pole tight to the concrete, that would be dumb.

Typical spec is double nuts, level the pole and grout under the pole leaving a nice chamfer to let the water run off.

Right you are, good comment.

 

[Electron_Sam78]

Thanks for the replies. Sounds like there are a few different ways of doing the same job but all seem to work.

 

[Fulthrotl]

I'm going to be installing 5 light pole bases which will be a first for me. The specs say 5' in the ground with rebar cage but that's about it. How do you guys make the rebar cage? Sections tied together to make a square then several of those tied to vertical sections to make a 3D rectangle? I saw one post where the horizontals were bent in circles with verticle bars tied to it to make it a cylinder. I guess you would do that with a torch? Also I planned on putting my sono tube all the way down into the ground the 5 feet but I saw an older post where some disagreed with that. Also can fiber reinforced concrete take the place of rebar? I can make the decision even though the specs say rebar. The specs are borrowed from another contractor that put poles on this property previously.

well, the pole manufacturer may have a "standard" base for a specific
pole and light head combo drawn up, but as was mentioned, there
probably better be an engineers stamp somewhere on this before you
dig the hole....

once you have a drawing, and holes dug, and a rebar cage built and sitting
on chairs in the hole, and a sonotube stuck in there and plumbed and set
to correct height.... then you can put in your part.. the j bolts, pipe, etc.

i've done a lot of these over the years, and here's how i do it.... most
guys drill a piece of plywood with the bolt pattern... i get the pole
makers cut sheet, and go to my little sheetmetal shop a mile up the
road from my house.... and have them shear some 14 guage or 12 guage
mild steel, and punch the holes in the correct places to fit the bolts.

then i grease the threads on the j bolts, and using the correct galvanized
nuts, put the first nut on all the way down, and back it off a turn.... then
i put the bolts in the template, and run the other nut down tight, putting
the j hooks facing each other.... put a couple stakes across the sonotube
and sit the template on them.... put pipe up the center, out the top, and
stubbed thru the side of the sonotube deep enough to meet correct depth
required below finished grade....

and i MAKE SURE that the bolts are oriented so the heads on the poles
line up in whatever pattern the drawings show.... putting a straightege
on the bolts and sighting at the next base in the row works well...

i did mazda's design center in calif, and set the poles.. the bases were
done by someone else... and after the poles were set, mazda took
aerial photos of the lot, and circled the ones where the light heads
were not perfectly straight, and said.... "fix these..." after the job was done.

i've been told metal templates are a waste of money, but one base with
with one bolt off, so you can't set the pole cancels that out, in my book.

 

[BullsnPyrs]

PreCast Bases

PreCast Bases

We used to do a lot of poles and pouring your own base was always the last choice. Fiberglass or concrete poles were the fastest and easiest to install but aren't always acceptable cosmetically. If a direct burial pole couldn't be used a pre-cast base was the preffered solution. Then would be haveing a contracor build the base on site and have electricians build a base as a last resort. There are many factors to consider besides the direct cost of the base. Scheduling for one. We did a lot of multi-site, muti-location projects. Having our bases ready to go in the ground and set the pole when our auger truck showed up was more important than having the truck there to dig a hole then come back to set the pole. Pre-cast products all come with a stamped drawing to cover the engineering liability. The drawing in post#10 was from a pre-cast base supplier.

 

[220/221]

Dig the hole

Drop in the cage, install conduit.

Set sonotube. 2x4 form is about 6" above bottom of tube.

Pour concrete, ( tamp, set bolts)

Tamp top with a "potato masher" (drywall mud mixing tool).
Beat around the sonotube several times with a baseball bat.

Set the templated bolts, landing the bottom nuts on top of the concrete. Finish the top with a round edging tool and a 6" putty knife. Peel the from and finish the sides with a sponge float while its still workable. This can be anywhere from 45 minutes to 2 hours depending on weather and how wet/dry the mix is.

I typcally set the bases at about 30" high. The cage wil land 3" below the top. We have the cages fanricated. Three rings at the top, 2" apart, then every 12" Leave anout 6" legs at the bottom then slip PVC over them to keep them out of the soil.

Barricade and go home

I've done better finishes but it was like 150 degrees that day.

 

[Electron_Sam78]

*

*

Dig the hole

Drop in the cage, install conduit.

Set sonotube. 2x4 form is about 6" above bottom of tube.

Pour concrete, ( tamp, set bolts)

Tamp top with a "potato masher" (drywall mud mixing tool).
Beat around the sonotube several times with a baseball bat.

Set the templated bolts, landing the bottom nuts on top of the concrete. Finish the top with a round edging tool and a 6" putty knife. Peel the from and finish the sides with a sponge float while its still workable. This can be anywhere from 45 minutes to 2 hours depending on weather and how wet/dry the mix is.

I typcally set the bases at about 30" high. The cage wil land 3" below the top. We have the cages fanricated. Three rings at the top, 2" apart, then every 12" Leave anout 6" legs at the bottom then slip PVC over them to keep them out of the soil.

Barricade and go home

I've done better finishes but it was like 150 degrees that day.

So you push the bolts into the concrete? Are they 3/4"x30"? Is it hardto push them in?