concrete for fence posts

[Eric_Phillips]

I am putting up vinyl fencing from Ramm fencing. they want concrete in each hole. I was at Lowes and they have fast setting concrete that says it can be used dry in a post hole. Then there is the standard concrete. The quick set is almost twice as much as the normal stuff. Can I put the normal setting stuff in dry or do I need to mix it. I am looking at 69 posts and the 80lb bag of the normal stuff says about 2.5 bags per hole. That is 172 bags or 13800lb of concrete. Any tips on doing this myself? Should I rent a portable mixer and so it all wet?

 

[Egon]

My back aches just thinking of that many bags of cement.

Is it possible to get a small ready mix truck out and have a drive by the hole filling??

The regular stuff can go in dry and then add water later. It will set up.

 

[J_J]

I am putting up vinyl fencing from Ramm fencing. they want concrete in each hole. I was at Lowes and they have fast setting concrete that says it can be used dry in a post hole. Then there is the standard concrete. The quick set is almost twice as much as the normal stuff. Can I put the normal setting stuff in dry or do I need to mix it. I am looking at 69 posts and the 80lb bag of the normal stuff says about 2.5 bags per hole. That is 172 bags or lb of concrete. Any tips on doing this myself? Should I rent a portable mixer and so it all wet?

Just pour the dry stuff, straighten up the post, pack a little. The ground moisture will cause it to set up. Add a gal of water to the hole if you want. A little rain wouldn't hurt at all. It is much easier to put the bag on the ground and slice the top, and pour in the hole. Lot less work.

2 1/2 bags @ 80 lbs sounds a bit much.

 

[bpattie]

I have seen an awful lot of vinyl fences go up without concrete, at least here in Colorado. they just tamp the hole. I have put up several miles of wooden post fences and have only used concrete in the corner and periodic h brace.

 

[pickngrin]

I agree that 2.5 80lb bags per hole seems like a lot. As I recall 4x4 posts 24" deep into 8-9 inch holes required 1.5 - 2 60lb bags.

I do like the fast setting concrete and have had good results with it, but it is expensive. JJ's idea of pouring in the dry stuff and letting it set up with ground moisture is intriguing. If you've got 69 holes to do why not try a couple using this method and see if you're satisfied with how they set up? This would save a lot of labor and $$.

 

[Duffster]

Use the normal stuff and pour it dry. Unless you have EXTREMELY dry soil you will have plenty of moisture in the soil for the concrete to set.

 

[J_J]

Has anybody had extra cement laying around? I put 4 bags under some wood with a tarp over it, and later when I wanted to use some of it guess what, it was solid. I learned later to put the bags of cement in plastic bags and duct tape closed.

 

[Therios Pendragon]

I never thought that regular cement would set up... but I have had those stupid bags that were solid after little time here in the Oregon humidity...

So now for the stupid question of the day... what is the difference between the two types. I always wondered about the pour and then wet kind and how it physically differed.

So I can't help but to wonder if there were any issues with regular concrete curing with very little moisture... I know those bags that I find aren't very solid... certainly even with a little rain, those bags are NOT as solid as properly mixed cement.

 

[Mike120]

With vinyl posts you do not want to rely on rain/ground water to set the concrete. Pour water in the hole before and after the concrete and "poke it with a stick" to make sure. Otherwise, when you thread your rails in the posts will crawl all over the place. Also, you may want to set your posts about an inch deeper than where you want the tops. After you've got the concrete in the hole, lift them slightly to get some concrete under the post. This will keep them from sinking later on.

After they've set overnight you can go through and adjust them up to level. You can only go up....down is not an option. If you lift one, pour a cup or so of dry concrete into the post with a bit of water. That will put something under the posts to keep them level. Concrete does not bind to the vinyl...that's why it is very important to put it in the hole...it's about making a stable hole. 80# is a good amount. Don't bother with the expensive quick set....in fact find a lumber yard...usually any place is cheaper than Lowes.

I've got over a mile of vinyl fence. If you do it right it will last a lifetime, if you do it wrong you'll spend a lifetime messing with it. Call Lee over at Triple S Vinyl Triple S Vinyl Sales, Inc. and get his marking cable, a notching tool, and a pair of rail removers. It will make the job a lot easier. By the way.....Ramm Fence has good products, but you can get vinyl a lot cheaper elsewhere.

 

[Eric_Phillips]

Thanks for he suggestions. I will use the normal stuff and add a little water. Mike I liked your suggestion to put the concrete in the hole and them pull the posts up to level but my posts have a square hole about 6-12" from the bottom. I am afraid the concrete will get in the hole and create a key not letting me raise the post. I am going to try to get them the correct hight to start with

Now for another question. I drilled some holes and some of them are just caving in. The soil is so sandy and rocky that is just doesn't hold together. Once I get the hole deep enough it will probably be 3-4 feet across. Could I just drop a sonotube, not sure of the spelling, in the hole then pack dirt around that and pour the concrete inside with the post?