Diameter for fence post concrete pour?

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Two swinging 6 foot gates. I'm going to use a 6x6x10' treated lumber to mount hinges on each side. It's going to be at least 3 1/2 feet deep, but unsure on the width of the pour. I was thinking 14 inches round? The auger can go 18 inches max. I'll reinforce the concrete with mesh.

Thanks,
 
Go 18" diameter 48" deep and skip the mesh. Put 6" of gravel in the hole before you put the post in
 
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I've dug and set fence posts as a side job for the past 25 yrs. For 6 x 6 posts I use 12" auger. No need for sono tubes as long as you are below grade. Use 100-120lbs cement per hole.. No gravel in bottom just kick in a little dirt once the post is in the ground and tamp dirt down with your level to keep post upright. Pour in cement until 4" from top of hole. Kick in more dirt. Plumb again and let post set for 48 hrs.
 
I built a 12' opening in a treated wood fence. I built a 6'long X 4" high 2x4 frame with one diagonal member. attached a 6' X 6' panel of fence to each side and swung each from a 4 X 4 post, braced diagonally to the next fence post. I mounted all the posts in concrete filled holes ~6-7" about 18" deep. It's been 3 years or so, and the gates are still straight and swing correctly. I dug the holes by hand, with an old Old-fashioned post hole digger, all 12 of them..

The thing is, How heavy are the gates? How strong, (dense), is the soil.?

I can do that here because this orange adobe like soil is very dense and hard as a rock , at least when dry. What is the condition of your soil? Also, do you need permits? If so, then all speculation is moot. You will build what you are allowed to build.

What dernp said will work anywhere, it would be overkill here.

Sounds like a fun project, good luck.
 
Originally Posted By: dernp
I've dug and set fence posts as a side job for the past 25 yrs. For 6 x 6 posts I use 12" auger. No need for sono tubes as long as you are below grade. Use 100-120lbs cement per hole.. No gravel in bottom just kick in a little dirt once the post is in the ground and tamp dirt down with your level to keep post upright. Pour in cement until 4" from top of hole. Kick in more dirt. Plumb again and let post set for 48 hrs.


What depth would you dig down too? Chicago area.

Can I do a 8in hole for the 4x4?
 
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Here in rainy South Florida, myself and most of my neighbors hang our driveway gates on 8x8 posts. We simply dig a 16 inch hole, 3-4 feet deep and pour concrete bags in dry. Wiggle the post true and add water, or not. Since it rains so often, the concrete hardens quite well.

I understand it's better to mix the concrete first. However for fences and gates, we have zero problems doing it this way.
 
Originally Posted By: Cujet
Here in rainy South Florida, myself and most of my neighbors hang our driveway gates on 8x8 posts. We simply dig a 16 inch hole, 3-4 feet deep and pour concrete bags in dry. Wiggle the post true and add water, or not. Since it rains so often, the concrete hardens quite well.

I understand it's better to mix the concrete first. However for fences and gates, we have zero problems doing it this way.



I've done this many times with fences. Works well.
We can't do it with decks anymore though. We have to dig a hole and form a 16"x16"x8" thick form at the bottom of the post to increase the footprint,then backfill.
It eliminates frost heave because the bottom of the post is larger than the diameter on top and increases load carrying ability due to the larger footprint.
You can buy plastic forms that the sonotube fits into,then backfill the entire form empty,pour concrete a foot lower than grade,install post,pour remaining concrete,then build the next day. It's a neat system.
 
Originally Posted By: dja4260
Originally Posted By: dernp
I've dug and set fence posts as a side job for the past 25 yrs. For 6 x 6 posts I use 12" auger. No need for sono tubes as long as you are below grade. Use 100-120lbs cement per hole.. No gravel in bottom just kick in a little dirt once the post is in the ground and tamp dirt down with your level to keep post upright. Pour in cement until 4" from top of hole. Kick in more dirt. Plumb again and let post set for 48 hrs.


What depth would you dig down too? Chicago area.

Can I do a 8in hole for the 4x4?



Wow. If that isn't a half [censored]ed way to build I can't say what is. Why do a halfway job. You've got the hole dug and a sonotube decreases concrete cost.
If I saw someone doing that on my site id hand them a shovel and tell them to dig it up and try again.


Op.
Use a sonotube. Less concrete which is a significant cost. For just regular posts you need to dig 48" to be under the frost line. If the posts are supporting a gate I like to go 6' deep to prevent the gates from sagging b
I'm an inter-provincial journeyman carpenter. If you'd like advice from an actual professional pm me and I'll happily walk you thru fence building.
And I don't pour any concrete until the fence is finished. I brace the posts solid. Build the center sections. Install them then pour once it's finished. It makes the assembly and finished product far better because you can twist the posts square to the fence sections and don't have to accomodate for inconsistencies because there aren't any.
I've easliy built 10000 lineal foot of fence. By myself. My methods and system is second to none with finished product being the most important part.
I've never once had to ask for a cheque because my customers gladly pay nor have I had to come back to make adjustments.
The only call back I've ever gotten is when the farm owner hit the gate post with his tractor and bent it,pushing the buried part of the post over 6 inches.
I had him dig it up,then we braced it straight and backfilled.
And post rot can be an issue. If you fill the post hole with crushed rock it aids water drainage extending the life of the post.
If you want to take shortcuts go ahead,but you only cheat yourself.
 
Yo Clevy -- Do you mix the concrete with water first, or do you pour the concrete into the post hole dry and then add water?
 
Originally Posted By: Merkava_4
Yo Clevy -- Do you mix the concrete with water first, or do you pour the concrete into the post hole dry and then add water?


What I do:

  • Dig hole with post hole digger app 3 ft
  • Pour in 6" of pea gravel
  • Put post in hole
  • Use clamps/screws with wood pickets/slats to level the post
  • Pour in the dry concrete/quickrete
  • Pour in water (generally 1 gallon)
 
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Originally Posted By: Clevy
Originally Posted By: dja4260
Originally Posted By: dernp
I've dug and set fence posts as a side job for the past 25 yrs. For 6 x 6 posts I use 12" auger. No need for sono tubes as long as you are below grade. Use 100-120lbs cement per hole.. No gravel in bottom just kick in a little dirt once the post is in the ground and tamp dirt down with your level to keep post upright. Pour in cement until 4" from top of hole. Kick in more dirt. Plumb again and let post set for 48 hrs.


What depth would you dig down too? Chicago area.

Can I do a 8in hole for the 4x4?



Wow. If that isn't a half [censored]ed way to build I can't say what is. Why do a halfway job. You've got the hole dug and a sonotube decreases concrete cost.
If I saw someone doing that on my site id hand them a shovel and tell them to dig it up and try again.


Op.
Use a sonotube. Less concrete which is a significant cost. For just regular posts you need to dig 48" to be under the frost line. If the posts are supporting a gate I like to go 6' deep to prevent the gates from sagging b
I'm an inter-provincial journeyman carpenter. If you'd like advice from an actual professional pm me and I'll happily walk you thru fence building.
And I don't pour any concrete until the fence is finished. I brace the posts solid. Build the center sections. Install them then pour once it's finished. It makes the assembly and finished product far better because you can twist the posts square to the fence sections and don't have to accomodate for inconsistencies because there aren't any.
I've easliy built 10000 lineal foot of fence. By myself. My methods and system is second to none with finished product being the most important part.
I've never once had to ask for a cheque because my customers gladly pay nor have I had to come back to make adjustments.
The only call back I've ever gotten is when the farm owner hit the gate post with his tractor and bent it,pushing the buried part of the post over 6 inches.
I had him dig it up,then we braced it straight and backfilled.
And post rot can be an issue. If you fill the post hole with crushed rock it aids water drainage extending the life of the post.
If you want to take shortcuts go ahead,but you only cheat yourself.


I've never seen this method used, but, whatever works.

as a young whipper, I did many of these jobs.
about 3 weeks ago, I went to a friend's place where we did a very similar job, some years back.
a 14" diameter hole, no sonotube. cost was not an issue, but the sonotube will cost more than an extra bag or so of cement, per hole.as well, there are only 2 holes involved.

about 54" deep hole, with about 6" of 3/4" clear stone. we paint waterproofing on anything below grade, especially the cut ends,the day beforethe job.this has always worked for me.
if we walk through the gate, my friend still makes comments about it's strength.he says we built it 17 years ago.proof enough that our method works well.
longevity of the job is the true test of workmanship -- regardless of your method.
have a good day, all.
 
Did it this morning. The 6x6 post are in 4ft. The 4x4 post are in 3.5-4 ft. I tweeked my back using the Auger. I ended up doing 7 post (two 6x6, five 4x4), and used 16 bags of 80lb concrete.

Please excuse me mess. It was raining in the morning.



 
Originally Posted By: Clevy
Originally Posted By: dja4260
Originally Posted By: dernp
I've dug and set fence posts as a side job for the past 25 yrs. For 6 x 6 posts I use 12" auger. No need for sono tubes as long as you are below grade. Use 100-120lbs cement per hole.. No gravel in bottom just kick in a little dirt once the post is in the ground and tamp dirt down with your level to keep post upright. Pour in cement until 4" from top of hole. Kick in more dirt. Plumb again and let post set for 48 hrs.


What depth would you dig down too? Chicago area.

Can I do a 8in hole for the 4x4?



Wow. If that isn't a half [censored]ed way to build I can't say what is. Why do a halfway job. You've got the hole dug and a sonotube decreases concrete cost.
If I saw someone doing that on my site id hand them a shovel and tell them to dig it up and try again.


Op.
Use a sonotube. Less concrete which is a significant cost. For just regular posts you need to dig 48" to be under the frost line. If the posts are supporting a gate I like to go 6' deep to prevent the gates from sagging b
I'm an inter-provincial journeyman carpenter. If you'd like advice from an actual professional pm me and I'll happily walk you thru fence building.
And I don't pour any concrete until the fence is finished. I brace the posts solid. Build the center sections. Install them then pour once it's finished. It makes the assembly and finished product far better because you can twist the posts square to the fence sections and don't have to accomodate for inconsistencies because there aren't any.
I've easliy built 10000 lineal foot of fence. By myself. My methods and system is second to none with finished product being the most important part.
I've never once had to ask for a cheque because my customers gladly pay nor have I had to come back to make adjustments.
The only call back I've ever gotten is when the farm owner hit the gate post with his tractor and bent it,pushing the buried part of the post over 6 inches.
I had him dig it up,then we braced it straight and backfilled.
And post rot can be an issue. If you fill the post hole with crushed rock it aids water drainage extending the life of the post.
If you want to take shortcuts go ahead,but you only cheat yourself.


Half assed way to do work? You got the wrong guy pal. I'm not sure who does your books but sono tube is also more costly than cement.
 
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