concrete for fence posts

[ToadHill]

I just put up a fence just like you are doing about 3 weeks ago. I mixed the concrete and was told by the manufacturer that the hole is the level for the cement to go up to. Don't put the concrete all the way to the ground level, but put it high enough that some of it flows into the big hole and gets inside the hollow post.

I mixed up my concrete pretty wet and figured after setting 4 posts how much I used on average then went out and bought the rest of the bags I needed. If I'd not done that I would have bought almost 1/3 too much.

 

[Dargo]

I mix the concrete. The reason I do so is I've been doing fencing for forty years or so. I've found that the dry set works best when doing a repair. I can take a twelve pound sledge and hit a post that was set dry set and the concrete will split top to bottom. The damaged post pulls right out. Mixed concrete on the other hand has to be dug out because it doesn't fracture so easy.

The toughest fence to set is in river bottoms out west where you have boulders and sand. The boulders mean the holes can't be done with an auger and the sand means you have to use water to keep it from caving in. If you're digging in sandy soil you water your holes as you go down and it won't cave in. Unless of course you use to much water.

Everyone wants to take the shortcuts. It's human nature. But every shortcut has its price. It would be nice to have a fence that looks like it was done right in the first place without all that work that doing it right takes.

I did several hundred feet of 7' tall privacy fencing around my pool and, even though it was a workout, I mixed all the concrete in a wheelbarrow by hand. For a 7' tall fence all of my posts were 10' vinyl posts. Per the manufacturer, as I bought directly from them to save money, I used five 80 pound bags of concrete per post. If I remember correctly, and I may have it backwards, it took 2 bags outside the post and 3 bags inside the posts. Each post also got two half inch rebar rods inside them that were 10' in length to make the concrete posts stronger. I literally had to climb a ladder and 'spoon' trowels full of concrete inside the posts until I had them within 1" of the top.

It was a major PIA, but now I'm glad I took the time to do it right. We've had several storms with winds in excess of 70 mph and the worst I've had was one section between posts blow out. All I had to do was go fetch all the pieces and put them back together using a stiff scraper. My posts are extremely solid and will not move. As harv said, unmixed bags of concrete bust up really easily and the posts can be lifted out.

I took all of the "bad" bags Lowes had. You know, the ones they had stored outside and had hardened. All I had to do was whack the bags a few times with a dead blow hammer and they were back to a dry mix. Not once did this not work. They all felt like yellow 80 pound bricks when I picked them up but each one easily broke up into the original powder mix with little effort. I definitely didn't want my fence to be set that way.

Attached is a picture of the fencing I put up this way.

 

[Mike120]

I did several hundred feet of 7' tall privacy fencing around my pool and, even though it was a workout, I mixed all the concrete in a wheelbarrow by hand. For a 7' tall fence all of my posts were 10' vinyl posts.

Nice Fence.....beautiful work! I've got a couple of vinyl gates where I filled the posts with rebar and concrete. Unfortunately it's only a 10' gate because I was told that was the limit. I've hit it a few times hauling equipment through there and have destroyed the post on the latch side. I only bent the hinge on the side filled wth concrete. It's solid as a rock. I'm going to put in another concrete filled one and hang another gate for a 20' opening. It's amazing how strong they are when filled with concrete.

 

[Mike120]

I just put up a fence just like you are doing about 3 weeks ago. I mixed the concrete and was told by the manufacturer that the hole is the level for the cement to go up to. Don't put the concrete all the way to the ground level, but put it high enough that some of it flows into the big hole and gets inside the hollow post.

That's actually a good idea, you just need to make sure your tops are level before it sets up. It's been a little over a year since I put any in and I got it from a local distributor. Which manufacturer were you using?

 

[ScottK]

Get the 60lb bags. I would use a cement mixer too. 2 x 60 lb bags per hole should be plenty unless your holes are really large. You don't need it to come to the top of the hole.