how would I make a base for this lantern post?

[BTL-A4]

I have a light on a post next to my grill that rotted and fell over. It was just a metal tube set in the dirt. Time to do it right, with a base set in a proper foundation.

I was going to use this to replace it.: https://www.homedepot.com/p/SOLUS-6-ft-Black-Surface-Mount-Aluminum-Lamp-Post-with-Cast-Aluminum-Base-and-Decorative-Cover-Hardware-Included-SM6-NCASTV-BK/314941228?MERCH=REC-_-rv_homepage_rr-_-NA-_-314941228-_-N&

How deep and how wide do I need to make a concrete base for the bolts? I'm assuming just a little deeper than the length of the bolts (allowing for some to stick up to allow attaching, of course). I'm guessing about 2" or 3" bigger than the base piece? I was planning on setting the bolts in the wet concrete.

I live in an area of SoCal that gets hot in the summer and occasionally freezes in the winter, so I want to make sure the concrete will be less likely to crack.

Thoughts and comments?

Thanks!

 

[Walkers]

Rule of thumb for posts is 1/3 in the ground, so 2 feet deep. For all that is, I would grab a post hole digger and run it down 16” or so, widen it up as needed and make a small form for the top and cast the concrete. then drill and anchor with tap cons after the concrete has set up a few days.

 

[joe49]

I have a light on a post next to my grill that rotted and fell over. It was just a metal tube set in the dirt. Time to do it right, with a base set in a proper foundation.

I was going to use this to replace it.: https://www.homedepot.com/p/SOLUS-6-ft-Black-Surface-Mount-Aluminum-Lamp-Post-with-Cast-Aluminum-Base-and-Decorative-Cover-Hardware-Included-SM6-NCASTV-BK/314941228?MERCH=REC-_-rv_homepage_rr-_-NA-_-314941228-_-N&

How deep and how wide do I need to make a concrete base for the bolts? I'm assuming just a little deeper than the length of the bolts (allowing for some to stick up to allow attaching, of course). I'm guessing about 2" or 3" bigger than the base piece? I was planning on setting the bolts in the wet concrete.

I live in an area of SoCal that gets hot in the summer and occasionally freezes in the winter, so I want to make sure the concrete will be less likely to crack.

Thoughts and comments?

Thanks!

Just me maybe but at 1/10th the cost, you can afford a can of black paint if you want, and just direct bury it.
https://www.homedepot.com/p/YARDGAR...d-Metal-Fence-Corner-Post-328944DPT/100322502

 

[lkjk]

I have 2 50 lb bags of concrete for my mailbox, with about 1 foot of dirt on top of that. Attached to that are stainless wedge anchor bolts that hold down a metal bracket to a 4x4 cedar post, that attaches to a metal bracket that my mailbox sits on. I've yanked on it a ton, doesn't move at all. I'm sure it would support 500lbs, not joking.

Yours isn't a mailbox i know, but same thing.

 

[Retroman]

Depending on the bolt length, you need a minimum 3" of concrete cover on the bottom of the bolts. So if there 12" long go at least 15" deep. I think for that application an 18" x 18" foundation would be good. There may be some engineering that comes with the post.

 

[mike93lx]

An aluminum lamp post will last nearly forever, even steel with paint will last a long, long time. There is nothing wrong with just burying it, especially on something that doesn't have any stress on it

If you really want to do concrete, I would grab a 2' piece of sonotube, probably 8". That is more than enough for a post.

Bag of gravel in the hole for drainage and to adjust the height of the tube.

 

[rlitman]

An aluminum lamp post will last nearly forever...

That's what I thought, until my wife pointed out how mine was cracked. Funny how the crack was at exactly the height of where the lawnmower wheel would hit it.

 

[mike93lx]

That's what I thought, until my wife pointed out how mine was cracked. Funny how the crack was at exactly the height of where the lawnmower wheel would hit it.

And who does the mowing?

 

[joe49]

That's what I thought, until my wife pointed out how mine was cracked. Funny how the crack was at exactly the height of where the lawnmower wheel would hit it.

Funny how that happens.

 

[rlitman]

And who does the mowing?

Exactly. Mostly her. Even though my nose is much bigger than hers, strangely I don't have the same blindspot right under it.

 

[mike93lx]

Exactly. Mostly her. Even though my nose is much bigger than hers, strangely I don't have the same blindspot right under it.

So it's your fault then. Got it

 

[no704]

This almost sounds like what the expanded foam post setting stuff was made for.

 

[Dig Doug]

I would go 15-18 inches deep make a wood square form for the top or buy a hunk of round sono tube ( concrete form - depot ) about $15 bucks. Make a template for the anchor bolts and wet set them or drill in wedge anchors after it cures.

make sure to run the electrical in a PVC conduit and make sure it’s grounded, keep the pvc conduit about an inch or 2 above the concrete surface to keep water out

 

[Retroman]

The post comes with the AB template.

 

[BTL-A4]

Thanks everyone!

The bolts look like they are about 6-8" long, so that means a 9-12" deep hole. This is only holding up a lamp, so it doesn't need to be overly strong.

Here are pictures of the site:


The ground is really hard; I have to use a jack hammer and digging bar. I'm not sure how deep the conduit goes, but I'm pretty sure it goes into the BBQ to the left, so maybe 20" or so. I can look inside the BBQ and see.

You can see the rotted old post in the photo. It's aluminum. The conduit sticks up almost 4 feet.

The expanded foam is an intriguing idea. I'd like the top of the base to look somewhat nice and it does need to be flat to mount the base (if I go that route) and I know I can make concrete smooth. The foam may or may not expand enough, but I think I can shave it down/shape it with a surform. I may just bury it below the surface; depends on how deep I need to make the hole and whether I use a base or just place the post in the concrete.

I can't believe how expensive the post/base all-in-ones are!

 

[Jim_No_Garage]

FYI - the expanding foam needs an "enclosed" area to contain it as it expands. I had a \_/ shaped hole for my mailbox post and the foam expanded up and out, away from the post. I quickly chipped it off and got 2 bags of quick-crete and it's been in place ever since.

I would use it again in the right circumstance.

Cheers

Jim

 

[willy3486]

I found a vintage street lamp in the stuff my inlaws had as I was going through their stuff after they passed. My wife wanted it on our backyard patio when we had concrete poured. The light fixture frame was in good shape but it was missing the post and globe. I had some steel tubing that was a perfect fit to the base of the lamp fixture so I used that and bought a new globe. I dig a hole down beside the concrete about 2 feet or so and cut the steel pipe so it would be about 2 feet in the ground and 8 feet above. I then wired it and put the lamp up. I back filled with dirt, no concrete. We have never had issues with it and it has been up about 4 years now. This picture was right after we got the patio poured and light up.