Privacy fence, my builder is only using 1/2 bag of concrete per post

[ARCHIVED THREAD] - Privacy fence, my builder is only using 1/2 bag of concrete per post

Posted: 7/20/2005 8:55:36 AM EDT

1/2 of an 80lb bag per post, is that enough? they are using 1 bag on the corners.

seems like that is not enough, but I am no expert.

Posted: 7/20/2005 8:57:06 AM EDT

[#1]

A bag is enough for 1 cubic foot of concrete, properly mixed. How deep are the posts being set? How much do you want him to use? What does your contract specify?

ETA: Please tell me they're not just pouring the dry mix into the hole, then adding water and mixing in place.

Posted: 7/20/2005 8:59:04 AM EDT

[#2]

Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.

Posted: 7/20/2005 8:59:09 AM EDT

[#3]

Quoted:
A bag is enough for 1 cubic foot of concrete, properly mixed. How deep are the posts being set? How much do you want him to use? What does your contract specify?

Contract doesnt specify the amount of concrete per post. I just figured there is a rule of thumb for a 6' fence 10' post spacing.

Posted: 7/20/2005 9:01:21 AM EDT

[#4]

Quoted:
Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.

Wrong. You actually want the fence to move with the soil. The embedment depth of the posts only needs to be enough to provide sufficient lateral restraint.

Posted: 7/20/2005 9:02:16 AM EDT

[#5]

Depends on what type of fence you're supporting. When I set my fence 2 years ago, I used 1.5 to 2 bags per post (between 2 and 3 foot deep, 12" square) and at the corners and gate posts I used 3 bags (16" square 3 foot deep).

My fence is custom between the posts and they run 8' to 10' not the typical 6' length of a prefab panel. Most of my rigidity is derived from the posts, not the panels.

I'd be cautious using that amount - but it really depends on the soil and how damp it gets. An old section of fence I haven't replaced yet is set w/o concrete. But those posts wobble excessively.

my .02 YMMV

Posted: 7/20/2005 9:04:32 AM EDT

[#6]

Quoted:
Quoted:
A bag is enough for 1 cubic foot of concrete, properly mixed. How deep are the posts being set? How much do you want him to use? What does your contract specify?

Contract doesnt specify the amount of concrete per post. I just figured there is a rule of thumb for a 6' fence 10' post spacing.

If the post hole is 8" diameter and 12" deep, there is only 0.35 cubic feet gross volume. Subtract for a 4x4 post, and there's only 0.24 cubic feet net volume. They might be using about the right amount.

Posted: 7/20/2005 9:06:36 AM EDT

[#7]

Quoted:
Depends on what type of fence you're supporting. When I set my fence 2 years ago, I used 1.5 to 2 bags per post (between 2 and 3 foot deep, 12" square) and at the corners and gate posts I used 3 bags (16" square 3 foot deep).

My fence is custom between the posts and they run 8' to 10' not the typical 6' length of a prefab panel. Most of my rigidity is derived from the posts, not the panels.

I'd be cautious using that amount - but it really depends on the soil and how damp it gets. An old section of fence I haven't replaced yet is set w/o concrete. But those posts wobble excessively.

my .02 YMMV

WOW! And I thought I overbuilt stuff! That's not a fence, that's a fortification! Good work!

Posted: 7/20/2005 9:08:56 AM EDT

[#8]

I used about 3/4 of a bag on a post and I still have a slight wobble.

NBut then again that is with me as the builder so.......

SGat1r5

Posted: 7/20/2005 9:09:09 AM EDT

[#9]

Quoted:
Quoted:
Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.
Wrong. You actually want the fence to move with the soil................

Oh, yeah. That must be how they do it in California. Couple of weeks ago I saw this California suburb and the fences were moving. So were the houses. Now that I think about it, so were the yards and trees......

Posted: 7/20/2005 9:10:26 AM EDT

[#10]

Quoted:
Quoted:
Quoted:
Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.
Wrong. You actually want the fence to move with the soil................

Oh, yeah. That must be how they do it in California. Couple of weeks ago I saw this California suburb and the fences were moving. So were the houses. Now that I think about it, so were the yards and trees......

How deep was the frost line there in California?

Posted: 7/20/2005 9:10:29 AM EDT

[#11]

i am building a privacy fence right now, and we only used one 80 lb bag per post. will used 3 on the gates to make sure they will be secure. for 8 foot posts you want 2 feet underground. 9 foot posts, 3 feet underground, etc... i rebuilt my moms fence like this after hurricane Ivan last year, and it recently survived hurricane Dennis fine. it did better than some of the "professional" jobs that were done around the neighborhood.

Posted: 7/20/2005 9:11:35 AM EDT

[#12]

I just swapped 2 posts that warped, and I used one 80# bag for each. It looks like they used less on the original install. 8 foot post, 2 feet down, 6 foot fence.

The neighbor had his fenced moved, they just put dry mix in the hole and wet it down. That's lazy.

Posted: 7/20/2005 9:13:58 AM EDT

[#13]

I should hold.. When Morton Built my shed 1985. They did not even mix it around the poles.. They dumped it in dry...
I about flipped out (big argument). The next day it was hard as a rock.. Still is to this day.. Its been threw some serious storms.

Posted: 7/20/2005 9:15:58 AM EDT

[#14]

Quoted:
I should hold.. When Morton Built my shed 1985. They did not even mix it around the poles.. They dumped it in dry...
I about flipped out (big argument). The next day it was hard as a rock.. Still is to this day.. Its been threw some serious storms.

If they had mixed it properly, it would be harder than a rock. Concrete hardness has almost nothing to do with concrete strength.

Posted: 7/20/2005 9:16:03 AM EDT

[#15]

Quoted:
I just swapped 2 posts that warped, and I used one 80# bag for each. It looks like they used less on the original install. 8 foot post, 2 feet down, 6 foot fence.

The neighbor had his fenced moved, they just put dry mix in the hole and wet it down. That's lazy.

if you use the Quickrete "fast setting" concrete mix, that is how they tell you to do it. when you have 35 posts to set, that is almost 3000 lbs of concrete to mix.

i would rather be "lazy" next time.

Posted: 7/20/2005 9:22:44 AM EDT

[#16]

Quoted:
Quoted:
Quoted:
Quoted:
Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.
Wrong. You actually want the fence to move with the soil................

Oh, yeah. That must be how they do it in California. Couple of weeks ago I saw this California suburb and the fences were moving. So were the houses. Now that I think about it, so were the yards and trees......
How deep was the frost line there in California?

What's a frostline? or are you guys burying freezers for caches again?

We doan got to cho you no steenking frostlines.

We do have timberlines though.

Posted: 7/20/2005 9:26:30 AM EDT

[#17]

Quoted:
Quoted:
Quoted:
A bag is enough for 1 cubic foot of concrete, properly mixed. How deep are the posts being set? How much do you want him to use? What does your contract specify?

Contract doesnt specify the amount of concrete per post. I just figured there is a rule of thumb for a 6' fence 10' post spacing.

If the post hole is 8" diameter and 12" deep, there is only 0.35 cubic feet gross volume. Subtract for a 4x4 post, and there's only 0.24 cubic feet net volume. They might be using about the right amount.

8" X12"??? Thats not a hole, that's a divot.

When I put my fence posts in, the holes were 3' deep and about 12" square. Put 6" of rock on the bottom and plastic sleeves on the posts (gotta keep them fence posts dry or the termite eat them right up). Each hole took about 2 1/2 60# bags of concrete.

Posted: 7/20/2005 10:18:03 AM EDT

[#18]

We usually use 1 whole or 75% of a 60lb bag... We pour it in dry and then add water.

FWIW: None of the fences my friends and I have built for each other has fallen down during the last two hurricanes.

Posted: 7/20/2005 10:20:28 AM EDT

[#19]

If he was he the low bidder, you now know why.

Posted: 7/20/2005 10:44:42 AM EDT

[#20]

I put in a board fence years ago to contain livestock. Set the 7' posts ~24", filled with dirt and some gravel here and there. Worked fine until the posts rotted out 20 years later.

Posted: 7/20/2005 11:07:23 AM EDT

[#21]

If they are 80 pound bags then it should be enough,with or Wooden or Metal post My family, Brother in Laws, and I have gotten together 4 times in the last 2 years to build my older sisters backyard privacy fences at their new houses. We used 1/2 bag each post and in retrospect we could have used a little more ,It is a good idea to use 3/4 a bag on the corners for stability

Posted: 7/20/2005 11:11:49 AM EDT

[#22]

Quoted:
Quoted:
Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.
Wrong. You actually want the fence to move with the soil. The embedment depth of the posts only needs to be enough to provide sufficient lateral restraint.

Wrong. You want the post to be deep enough and the footing to be shaped to to resist local frost-line / heaving.

And to the thread-starter - a 1/2 bag isn't enough. The contractor is skimping a whole $1.50-$2.00 per post and FUCKING you on your fence.

Posted: 7/20/2005 11:12:51 AM EDT

[#23]

Quoted:
WOW! And I thought I overbuilt stuff! That's not a fence, that's a fortification! Good work!

Gots to hold back teh zombies.

Posted: 7/20/2005 11:16:33 AM EDT

[#24]

Quoted:
Quoted:
I just swapped 2 posts that warped, and I used one 80# bag for each. It looks like they used less on the original install. 8 foot post, 2 feet down, 6 foot fence.

The neighbor had his fenced moved, they just put dry mix in the hole and wet it down. That's lazy.

if you use the Quickrete "fast setting" concrete mix, that is how they tell you to do it. when you have 35 posts to set, that is almost 3000 lbs of concrete to mix. i would rather be "lazy" next time.

+1

I've done it, but granddaddy was a bricklayer / mason and I learned the Proper Way - pouring it in and wetting it sure didn't seem Right.

Posted: 7/20/2005 11:19:13 AM EDT

[#25]

Quoted:
Depends on what type of fence you're supporting. When I set my fence 2 years ago, I used 1.5 to 2 bags per post (between 2 and 3 foot deep, 12" square) and at the corners and gate posts I used 3 bags (16" square 3 foot deep).

My fence is custom between the posts and they run 8' to 10' not the typical 6' length of a prefab panel. Most of my rigidity is derived from the posts, not the panels.

I'd be cautious using that amount - but it really depends on the soil and how damp it gets. An old section of fence I haven't replaced yet is set w/o concrete. But those posts wobble excessively.

my .02 YMMV

Building my fence in a few months. I want it like this!

Posted: 7/20/2005 11:24:58 AM EDT

[#26]

Quoted:
Quoted:
Depends on what type of fence you're supporting. When I set my fence 2 years ago, I used 1.5 to 2 bags per post (between 2 and 3 foot deep, 12" square) and at the corners and gate posts I used 3 bags (16" square 3 foot deep).
WOW! And I thought I overbuilt stuff! That's not a fence, that's a fortification! Good work!

Thanks! Actually - the one corner/gate post has already managed to crack the foundation. 6x6 post, with a double leaf 10'-0" gate hanging on it - all treated lumber. I framed the gate up in the driveway and then had to get 2 guys to help me lift it into the truck to cart around to the other side of the house. :)

Quoted:
Building my fence in a few months. I want it like this!

Be happy to share the plans - gotten many a compliment from the neighbors that it looks 1000% better than any store bought privacy unit. I'll have to dig up the pics I took...

Posted: 7/20/2005 12:16:20 PM EDT

[#27]

Quoted:
Quoted:
Just be sure he sets them below the freeze line so they won't heave during the winter, Tex.
Wrong. You actually want the fence to move with the soil. The embedment depth of the posts only needs to be enough to provide sufficient lateral restraint.

Oh yeah...tell us why you would want a fence to move with the soil (and never go back to exactly the same place) as opposed to being deep enough in the ground so that it doesn't move.

Posted: 7/20/2005 12:28:22 PM EDT

[#28]

Quoted:
Oh yeah...tell us why you would want a fence to move with the soil opposed to being deep enough in the ground so that it doesn't move.

For a privacy fence with pickets that extend to the ground, if the posts are anchored below the frost line, the soil will eventually heave up into the pickets, which will either promote deflection or rot of the pickets. If the posts, rails and pickets are all founded together with the soil, the gap between the bottom of the picket and the earth will remain constant, more or less. In areas of less-expansive soils, this becomes less of an issue, but those areas also tend to have shallow or no frost lines, so the point is moot.

Posted: 7/20/2005 12:37:51 PM EDT

[#29]

Quoted:
Quoted:
Oh yeah...tell us why you would want a fence to move with the soil opposed to being deep enough in the ground so that it doesn't move.
For a privacy fence with pickets that extend to the ground, if the posts are anchored below the frost line, the soil will eventually heave up into the pickets, which will either promote deflection or rot of the pickets. If the posts, rails and pickets are all founded together with the soil, the gap between the bottom of the picket and the earth will remain constant, more or less. In areas of less-expansive soils, this becomes less of an issue, but those areas also tend to have shallow or no frost lines, so the point is moot.

I guess everybody does things different. I'd trim the pickets a bit higher at the bottom rather than have posts pointing all over the place and stretching the rails loose after a few years.

Posted: 7/20/2005 4:29:07 PM EDT

[#30]

Quoted:
Quoted:
Quoted:
Depends on what type of fence you're supporting. When I set my fence 2 years ago, I used 1.5 to 2 bags per post (between 2 and 3 foot deep, 12" square) and at the corners and gate posts I used 3 bags (16" square 3 foot deep).
WOW! And I thought I overbuilt stuff! That's not a fence, that's a fortification! Good work!

Thanks! Actually - the one corner/gate post has already managed to crack the foundation. 6x6 post, with a double leaf 10'-0" gate hanging on it - all treated lumber. I framed the gate up in the driveway and then had to get 2 guys to help me lift it into the truck to cart around to the other side of the house. :)

Quoted:I recently put an extremely heavy metal gate up on my farm. 16 foot long galvenized. I hate a sagging gate, so I got a 12 foot 6x6 treated post dug down 4 feet with a tractor auger and put 280 pounds of concrete in the hole. I let it cure for 30 days then put my gate on. It is solid as a rock.
Building my fence in a few months. I want it like this! hr

Be happy to share the plans - gotten many a compliment from the neighbors that it looks 1000% better than any store bought privacy unit. I'll have to dig up the pics I took...

Posted: 7/20/2005 5:07:26 PM EDT

[#31]

When we built a friends fence a while back, he did a lot of research, cause he wanted it right. I cant remember the exact dimensions of the hole.... but each post was set with 1.5bags of quickcrete. The original fence built with his house was way less, and wobbly.

Posted: 7/20/2005 5:19:06 PM EDT

[#32]

Ok - here's what I built:
From the driveway of the low section which also hosues firewood storage on the backlot side:

and from the back side:

and the gate on the far side of the house - not finished in this pic - the lattice work isn't in yet and the excess of the 14' 6x4 (wrong size stated earlier - forgot it got cost engineered

) needs trimmed:

My take on the frostline issue - dealing with the grade pushing along the base of the panels is easy compared to straightening a fence that is wavier than a drunk boater because the posts heaved. I know I'm not below the max frost line with my line posts, but the end posts will hold true.

Posted: 7/20/2005 5:59:03 PM EDT

[#33]

I used to work for a fencing company. Some how I was the foremen even though i had no prior expereince. I ran split rail (horse fence) for weeks. About 300-400 feet a day. We normally used 3/4 of a bag per a whole. My boss would tell me to use a half, and i'd tell him to go fuck himself.

And yes, for fence post you put the concrete in dry. Fencing sucks, but theirs money in it. Its hard work, i was always glad i got to do the smart shit and not the labor work.

Matt

Posted: 7/20/2005 6:04:54 PM EDT

[#34]

My summer job in high school was working for a fence company. Man, what a life. Outside every day, and free beer every day at quitting time! When we set posts for privacy fences, the holes were about 18 inches deep, and always wider at the bottom than at the top. We had a large gas powered mixer mounted on the back of a gravel truck where we mixed all the gravel (two buckes of water, one 90 lb bag of concrete mix, then I shoveled grave into it until it was the right consistency). I don't know how many bags per hole it equated to, but we'd fill the holes until they were about an inch below the top of the hole. FWIW