Concrete to set a post question

[blinn]

I'm setting a few 4x4 treated posts. The second one might have been a bit wet and little longer to set up. I thought that I read somewhere that if the concrete was slower to cure that the concrete would be stronger but I might be misremembering Anyway, I set it yesterday and we're supposed to get a couple days of rain, should I leave it to get rained on or should I try to cover it with a tarp?
Thanks

 

[Walkers]

It’s fine, leave it.

 

[rayra]

You remebered correctly. Wetter longer results in stronger.

 

[Leaflessshadetree]

Extending cure time due to having extra water in the mix isn't the same as slowing the cure by keeping the surface wet. Rain a day or two after pouring shouldn't hurt anything.

 

[rayra]

No, that's correct, you don't want a sloppy wet mix, that's bad for strength. Re-wetting or keeping it damp for a protracted period AFTER the pour will yield better strength.

 

[PCustoms]

The concrete will be fine, assuming it has started to set.

But don't set wood posts directly into concrete, it's really not a good way.

 

[MarcSeattle]

If not in concrete, what's the best way to set wood posts?

I've been thinking about that too. I want to create a combination fence and plant arbor. Fence will be the standard 6' but at one end there will be about 25 feet of length that will extend up another 3' for a total of 9' high with an arbor. (I'm hiding the view of my neighbor's garage.) That height would look spindly with 4x4 posts so I'm going to use 6x6. What is the best method these days? I'm in Seattle so frost heave isn't an issue. The soil is sandy glacial till. Easy to dig, drains well.

 

[rancherbill]

......that will extend up another 3' for a total of 9' high with an arbor. (I'm hiding the view of my neighbor's garage.) ....

Have you applicable bylaws. A 9 foot fence is a monster. Here, 6 feet is the max.

 

[mike93lx]

If not in concrete, what's the best way to set wood posts?

I've been thinking about that too. I want to create a combination fence and plant arbor. Fence will be the standard 6' but at one end there will be about 25 feet of length that will extend up another 3' for a total of 9' high with an arbor. (I'm hiding the view of my neighbor's garage.) That height would look spindly with 4x4 posts so I'm going to use 6x6. What is the best method these days? I'm in Seattle so frost heave isn't an issue. The soil is sandy glacial till. Easy to dig, drains well.

Metal brackets.

No wood in concrete for my either. PT or not, it will rot out at ground kevel from water sitting there

 

[TurnipTruck]

We do have significant frost heave up here, so with thirty years experience of installing and maintaining horse fence (and lately, this orchard fence), we’ve learned what works and what gets pushed out.
I use a 6” auger on my post hole digger sunk four feet (to below frost depth here) or at least 30”, drop the post onto a flat rock in the hole, and good compactible driveway gravel compacted with a tamping bar every two shovelfuls until its slightly proud of the ground. This allows the PT post to dry as the gravel drains better than native soil. Far too often I have seen the inevitable cone of concrete squeezed out of the ground by frost.

I’m pulling the deer fencing taut with straps here. You can see the mounding at the bottom of the post.



that fence is nine feet out of the ground and uses 4x4s. I don’t think you need 6x6 unless it’s purely an aesthetic.

 

[FL Guy]

If not in concrete, what's the best way to set wood posts?

I've been thinking about that too. I want to create a combination fence and plant arbor. Fence will be the standard 6' but at one end there will be about 25 feet of length that will extend up another 3' for a total of 9' high with an arbor. (I'm hiding the view of my neighbor's garage.) That height would look spindly with 4x4 posts so I'm going to use 6x6. What is the best method these days? I'm in Seattle so frost heave isn't an issue. The soil is sandy glacial till. Easy to dig, drains well.

Here’s my 7’6” wood fence with a 2’ lattice on top.

 

[PCustoms]

If not in concrete, what's the best way to set wood posts?

We do have significant frost heave up here, so with thirty years experience of installing and maintaining horse fence (and lately, this orchard fence), we’ve learned what works and what gets pushed out.
I use a 6” auger on my post hole digger sunk four feet (to below frost depth here) or at least 30”, drop the post onto a flat rock in the hole, and good compactible driveway gravel compacted with a tamping bar every two shovelfuls until its slightly proud of the ground. This allows the PT post to dry as the gravel drains better than native soil. Far too often I have seen the inevitable cone of concrete squeezed out of the ground by frost.

I’m pulling the deer fencing taut with straps here. You can see the mounding at the bottom of the post.



that fence is nine feet out of the ground and uses 4x4s. I don’t think you need 6x6 unless it’s purely an aesthetic.

The gravel is the best answer I've found so far.

 

[Renegade1LI]

This is how I set them, I have wood posts 25 years old with no rot. Dig the hole, usually 8" for a 4x4 and back fill with dry concrete mix. Level the post, tamp the mix and add a little water. I do widen the bottom of the hole a little, prevents uplift.

https://www.lowes.com/n/how-to/setting-a-post-with-concrete#:~:text=Set%20the%20post%20into%20the%20form%20and%20make%20sure%20it's%20straight.&text=Pour%20the%20dry%20concrete%20mix,wide%20and%202%20feet%20deep.&text=Make%20sure%20the%20post%20is,allowing%20the%20concrete%20to%20set.

 

[Youngandfree]

This is how I set them, I have wood posts 25 years old with no rot. Dig the hole, usually 8" for a 4x4 and back fill with dry concrete mix. Level the post, tamp the mix and add a little water. I do widen the bottom of the hole a little, prevents uplift.

https://www.lowes.com/n/how-to/setting-a-post-with-concrete#:~:text=Set%20the%20post%20into%20the%20form%20and%20make%20sure%20it's%20straight.&text=Pour%20the%20dry%20concrete%20mix,wide%20and%202%20feet%20deep.&text=Make%20sure%20the%20post%20is,allowing%20the%20concrete%20to%20set.

Wood isn't the same quality as it was 25 years ago.

 

[PCustoms]

Wood isn't the same quality as it was 25 years ago.

I'm digging out cutoffs from under a deck built in 1985. Wash the dirt off and other then they are dark they look brand new.

 

[Youngandfree]

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[mbunimog]

Our 8 ft high deer fence used post driver to ram in the post with no concrete used

 

[swsman]

Here is what neighbor and I did yesterday.
Used PVC sleaves.
3' hole, 6" or so of gravel on the bottom.
Then 3 buckets of concrete per post.
Rest will be filled in with dirt we dug up from the holes.

Any issues with rotting of the wood posts, yank them out and replace as needed.

 

[MarcSeattle]

Have you applicable bylaws. A 9 foot fence is a monster. Here, 6 feet is the max.

The neighbor's garage backs onto the property line and is 10" tall. The fence will be 6' except the sections with the 9' arbor will be only the part of the fence in front of the two-car garage. So it's OK.

 

[bluedog225]

Gravel is the answer. I’ve used coarse sand as well but it may stay wetter. Concrete cracks, separates, and holds water next to the often wet wood.

 

[whateg01]

The neighbor's garage... is 10" tall.

Seems short!

 

[bdbecker]

...drop the post onto a flat rock in the hole, and good compactible driveway gravel compacted with a tamping bar every two shovelfuls until its slightly proud of the ground...

What size gravel are you using?

 

[Spareparts]

Back in the mid 70's worked for a Line Builder we were building a Hi-line across the Flint Hills of Ks. a lot of the fences were
built with rock posts, usually about 8" square. They would put a steel post in sometimes a 1/2 mile between them to ground
wire from Lightning Strikes. Was back out their in the early 90's and most of them were gone, replaced with T posts. They
were piles of the rock posts along the roads. Seen a Documentery on how the pioneers would find a ledge of rock and take
a star drill and hammer to drill holes into the rock, fill with water and let the freeze/thaw cycle break them off the ledge. Can
you think of sitting for day's hammering on a rock to get a fence post. Oh by the way they never rotted.

 

[TurnipTruck]

What size gravel are you using?

Driveways. _________________________ Postholes.

 

[MarcSeattle]

The neighbor's garage backs onto the property line and is 10" tall.

Seems short!

100 years old. Flat roof. Model Ts weren't very tall.

 

[SBAG]

I'm digging out cutoffs from under a deck built in 1985. Wash the dirt off and other then they are dark they look brand new.

Yeah, now they are missing one of the Cs and the A in CCA. Chromium and Arsenic have been gone for 20 years. Just copper left and that doesn’t cut it.

 

[racecougar]

The neighbor's garage backs onto the property line and is 10" tall.


100 years old. Flat roof. Model Ts weren't very tall.

How the heck do you get a Model T to fit in a 10" tall garage? Are we talking about a scale model of a Model T?

 

[dougf]

Yeah, now they are missing one of the Cs and the A in CCA. Chromium and Arsenic have been gone for 20 years. Just copper left and that doesn’t cut it.

Any recommendations for treatment? About to do a fence myself and I've been saving my used diesel motor oil and thought about soaking the bottom of the posts for a week prior to installation.

 

[whateg01]

How the heck do you get a Model T to fit in a 10" tall garage? Are we talking about a scale model of a Model T?

I thought maybe he was actually from Lilliput

 

[rancherbill]

The neighbor's garage backs onto the property line and is 10" tall. The fence will be 6' except the sections with the 9' arbor will be only the part of the fence in front of the two-car garage. So it's OK.

Good, but just remember just because the cool kids do something doesn't make it right. There's always the chance that your local govt will crackdown on scofflaws.