Planting Pole - How Much Concrete Needed?

[Davage]

This weekend I plan to plant the pole for my C-Band dish. The dish is a mesh 7.5 footer. I managed to salvage about 8 ft of pole when I took it down. I have a very good line of sight of the birds, so height isn't needed. I am planning on putting the pole 4ft in the ground and 4ft above the ground.. I saw some pre-mixed concrete, the just add water variety, at the home improvement store for around $6 / bag. I was thinking about using 2 of those bags which I estimate are 50lbs each. I was also planning on getting a bag of crushed gravel in order to pour some if to the bottom of the hole before I put the pole in. The leftover gravel I'd put at the top of the hole. I plan on selling my house within the next 3 years, so I don't want the concrete coming right to the top, because I plan to cut the pole off an inch or two below the dirt line and take the dish with me when I leave.

Does 100lbs of pre-mixed concrete sound like enough?

I've read about drilling a hole through the pole and putting a bolt through it so that the dish won't spin in the concrete afterwards, so I plan to do that.

How long should it take to set before I can put the dish on the pole? The ground here right now is (as my funny brother would say) "Dryer than a popcorn fart", because we've had very little rain in the past month. The weather forecast shows some rain for tomorrow, but not much accumulation expected.

If I plant the pole on Saturday afternoon, should it have cured enough by Monday night to put the dish up?

 

[Anole]

Until you get better advice, let me say what I've seen posted here in the past.

One bag of cement for each foot of dish diameter, suggesting 7 or 8 for your setup.
Of course, they should take into account how tall the pole is out of the ground, so I'd keep asking.
Personally, I'd use two bags just for a 3' dish...

On sale, the bags of ready mixed usually go for $3.

And I've read to wait 24 hours for the quick set before mounting your dish.
I would water down around the hole pretty well if the ground is as dry as you say, maybe add a wee bit more water to the mix, and lay a wet blanket over the exposed cement so it doesn't dry out in five minutes.

Hopefully, that'll get you thinking.
Maybe search the forum for some already-published advice.
Or maybe the more experienced will chime in.

 

[Davage]

Thanks anole.. I'll grab 4 or 5 bags at a minimum. The big box store is less than a 4 minute drive away, so if I run out, I can quickly get more. I have a major kitchen renovation project happening on Sunday, so I planned to plant the dish Saturday afternoon, and let it set until at least Sunday evening. In reality, I'll probably be totally exhausted after the kitchen renovations are done, and I will wait until Monday night. Thanks for the tips on wetting down the dirt inside the hole, and mxing it a little on the wet side.

 

[iammike]

I planted my 8 footer a couple summers ago on a 10.5 foot pole. I had a little over 3.5 feet in the ground in a hole about 18 inches in diameter. I think the rule of thumb for depth is to plant at least one third of the pole in the ground. If I remember right I used about 8 60lb bags of ready mix. I also filled the pipe up with concrete for added strength. That was probably overkill as I used schedule 80 steel, but it hasn't budge a bit in 2 years and we get a lot of wind here. I let it cure for a week before I attempted to mount the dish. I don't remember all the particulars, but it seems like in 24 hours concrete gets about half it's strength, in a week about 90%, but it doesn't fully cure for around a month or so. If it were me I'd set the pole this weekend and put the dish on it next weekend.


Here's a link with all sorts of good info on planting your BUD:

Satellite Footprints by Dish Size - Ground Pole Installation, Pad Mount Installation, Wind Loading

Good luck digging in that dirt. That's about the way mine was, and it took me a couple hours to dig the hole and several more the next day mixing concrete and planting the pole. I don't care what you're doing in the kitchen, it's going to seem easy after the work installing the pole.

 

[caddata]

...Does 100lbs of pre-mixed concrete sound like enough?...

Believe it or not, a head on wind of about 40 MPH could apply a load of approx. 13 pounds per square foot on your dish. If it were solid, the load could be as much as 60 pounds per square foot.

3.75 x 3.75 x 3.1416 x 13 = 574.3 pound wind load applied to dish

If your 4 foot pole gave the dish a 4:1 mechanical advantage then: 4 x 574.3 = 2297.2 pounds of force applied to the post. Lots more than you would imagine. You would hope that the wind load would overcome the dish's attachment at the top of the post and just rotate the dish on the post instead of bending the post.

All things considered, I'd put about 3 or 4 90 pound bags (or a like equal of 60 pound bags) in the hole. No need to try and fill the post with concrete, because it doesn't add to the post's ability to resist bending.

This is assuming that the post is 3.5" or 4" schedule 40 black pipe.

Harold

 

[iammike]

No need to try and fill the post with concrete, because it doesn't add to the post's ability to resist bending.

Harold

Harold,

I'm just going by the instructions in the link I posted, but they indicate that it will make the post stronger if you fill it with concrete at least until it gets up above ground level. It will also help reduce oxidation.

Mike

 

[Gray1]

I just set my post two weeks ago. It was for a 7 1/2 Perfect 10. The hole was
36" deep. 18" around at the top and 24" around at the base. It took 8 80lb bags of premix. I was told to wait 10 days until I sat the dish on the post. Concrete builds strength as it cures. It was a nine foot pole. Three feet went into the ground and six feet above ground. When I sat the dish, the pole remained dead plumb.
Just my 2 cents


allen

 

[Lynskyn]

I used to use about 6 80 lb. bags of concrete for a job like that. Be sure to get concrete mix that says "high quality" because some of the cheaper mixes have very little rock and not enough cement. I routinely would wait a good 24 hours before putting the dish on the pole. I would mix it very well in a wheel barrow with just enough water to make it muddy but not too watery, then poured it in the hole around the pole. Never had a problem with the pole moving or shifting when I did it that way. Other dealers would use "Quick Rock" to make the concrete set up fast and would do a one day install, putting the dish on the pole withing an hour or two of pouring. I ended up repairing many of their installs after the concrete turned to powder.

 

[GeorgeLV]

Does 100lbs of pre-mixed concrete sound like enough?

You could barely get away with that for a pole mount of a pizza dish. 400 or 500 lbs is the bare minimum. Make sure to notch the pole so it doesn't turn in the concrete. Also, if the soils in your region aren't stable, you'll have to take the appropriate remediation measures.

 

[chefwan]

I used 5 bags od quickcrete 80lb bags and it worked for me good luck

 

[truckracer]

My 7.5' sami mesh dish is on a sch 40 3.5" pipe in the ground 3 feet with rebar cross drilled in the bottom of the pipe to keep it from turning. My hole is about 12 inches in diameter and it has (7) 80 pound bags of quickrete around it. The pole is also filled with concrete to the top and the pole sticks out of the ground about 7 feet.

Never had any problems or mis alignments. We have had some pretty hard wind since I installed it.