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Process for Building a Fence

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#22 ·
hdrider_chgo said:
In my experience, wood posts will last longer if you don't set them in concrete.

I'm replacing a wood fence now at my house that was put in about 15 years ago, not by me. Cedar posts set in concrete, all of them rotted.

You don't need concrete to get posts solid.
Click to expand...
Yeah, cedar post set right into concrete is not a good idea, but the pressure treated posts will last longer. PT with a little gravel in the bottom of the hole set in concrete I bet will last you 30 years.
 
#23 · (Edited)
I'm not sure why concrete is considered necessary nowadays. I grew up on a farm and probably set hundreds of fence posts solid without concrete.

In any case, here is a photo of my solution to rotten posts. It's my own fence and only about 30' long, so budget isn't a big issue.

The steel was coated with cold galvanizing compound, then painted before setting in the concrete. Bolts run between the steel within the concrete. The new cedar post will replace the spacers, and be held up off the concrete.

As soon as the posts are set, I'll replace the rest of the fence.
 

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#27 ·
Ways I have seen posts set:

2' deep -4' deep.

Bottom material:Nothing in the bottom of hole first; gravel bottom; crushed rock bottom

Fill: Gravel fill; Sand fill; Concrete fill

Cap: No cap; concrete or mortar cap (begins on grade, and looks like a mushroom top - supposed to shed water away from the post / gravel)

Easiest way to deal with getting concrete in holes is to use something like Quikrete4000, and follow their directions for setting posts - no mixing, just pour water, dump in concrete, pour more water, etc. Costs more per bag, but goes really fast.

One unique feature of using sand to fill the hole is if it is moist, you can usually wiggle the pole after it has been set, and pull it out of the hole, and reset it in the same hole. Convenient of you have to replace a pole, but not generally something I'd use for a 6' almost solid fence without going down 4' in many soils. By then, you may not be able to wiggle it back out and replace it without having to re-dig the hole. Nice way to go for shorter fences and more open fence designs.

Most of the load on a fence (ignoring gates) will be wind load. Solid fence has the highest. Even the little 1/4 - 3/8 " gaps in a board fence helps a lot to keep the wind load down. Wider gaps help even more. Depending on the soil and wind, most places I could go 3' down, put gravel or crushed rock in the bottom, set my post, then back fill with sand and tamp and water it in to make sure it is tight. Top it off with a concrete cap. Besides shedding water away from the sand you just put in, the concrete cap will provide a little support against the pole being pushed over. If it gets too much load, the cap breaks, the pole leans over some in the sand, and the wind load is decreased. Straightening it back up and replacing the cap is easy.

What you need to do really depends on your soil and winds.
 
#28 ·
hdrider_chgo said:
I'm not sure why concrete is considered necessary nowadays. I grew up on a farm and probably set hundreds of fence posts solid without concrete.

In any case, here is a photo of my solution to rotten posts. It's my own fence and only about 30' long, so budget isn't a big issue.

The steel was coated with cold galvanizing compound, then painted before setting in the concrete. Bolts run between the steel within the concrete. The new cedar post will replace the spacers, and be held up off the concrete.

As soon as the posts are set, I'll replace the rest of the fence.
Click to expand...
Looks like a good solution. Wire or 3 board fences never need concrete, and I've set a bunch of the skip board fences with no concrete in 3' holes. I never used 6X6 - if I think I need added resistance to movement perpendicular to the fence face I"ll use 4X6.
 
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