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Installing a very nice custom fence and would like the new cca posts
to last. Instead of just backfilling with existing soil, a brown
loamy stuff with little or no sand, I plan to set them in gravel
approx. 4″ wide around the post and at base. The guy who sold me
the gravel thought this would be an invitation for water to fill-up
around the post, defeating the purpose. Also have heard some swear
posts last longer set in concrete, although I never do except if
posts are hanging a door or gate.
Any veteran post/fence people out there?
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Gravel will certainly invite water into each hole similar in how gravel around drain tile works. Gravel would be the path of least resistance for the water. Do not use gravel!
Use cement. you don't even have to mix it first. fill the hole, after the post is in it, about 1/3 way with water. Then slowly pour in dry quickcretet to near the top. If you work with the water to dry ratio, you will find a point that keeps all the extra cementious water from flowing over the top of the hole and all over the grass. The concrete mix will be right everytime as the excess water will simply be forced to the top and the concrete will settle down and be damp enough to givce a nice strong cure. If you like, you can only fill solid to within 3 inches of grade and finsh off with soil after the cement dries.
This process is actually so easy, you'll never mind cementing posts again...you may even look forward to it.
BTW, quick-crete now sells bags of concrete just for this purpose (pouring dry into hole of water) but I've been doing it this way long before they came out with this new idea and it has always worked beautifully for me. There's a good chance they're now just selling the same stuff in a different bag with a larger price.
Pete
*http://webx.taunton.com/WebX?128@@.eef99c7
*Noel, i put up about three hundred feet of fence with 4" square posts in concrete three years ago. I mounded up the concrete slightly around the posts so water would run away, just as the ground around a house is graded. These are still solid as can be. Last year i put five hundred feet of the same fence in with no concrete and i've already had to go back, excavate, and fill around many of the posts. These were all sunk two feet in the ground on a five foot fence.If you have many posts to do and don't want to hand mix a lot of mud, you can get a concrete truck to deliver, even drive along the line if it's accessible, and dump some in each hole, or you can wheelbarrow it to place. I hand-mixed for the first fence, at least a 90# bag per post--lots of work! I also overdug my holes and put 6" of sewer rock in the hole before the post went in. The next time i fence, i won't hesitate to do it right and do it once.
*I wonder if the posts movement was related to the shallow posts. Two foot posts and five feet of leverage seems like asking for movement. I will bet that even the concreted posts will loosen in time from wind pushing on the fence. Tom the Tree Guy
*Excellent point about the depth, Tom. In my case, i was putting chain link on the wood posts, so not much wind, but Noel's "very nice custom fence" probably means he has something with a lot more wind resistance that my fences.
*We don't even bother to put in water, just fill in the post-hole with Sacrete (locally available brand - about 1/2 the price of "Rapid Post"). I usually turn the mix over a few times in the wheel-barrow to make sure it's mixed, and sometimes add some small aggregate if the soil's soft. If it's in a wet area, we sometimes pour about 250ml of acrylic binder over the top, mix it in a little with a small trowel, and smooth up the top surface. Water from the surounding soil will migrate into the mix and harden it. - here's hoping I get enough work this summer that I don't have to build fences this year.
*The gravel attracting water theory is a problem solely based on the soil. In dry soil it wouldn't make much difference. 2' depth doesn't seem adequate, I usually go down 3 and up 5 max. Gravels cheaper than concrete, and easier to work with. Setting posts with a transit truck becomes a mad rush, with gravel you work at your own pace. Dumping redi-mix in the hole and adding water after is (in my opinion) wrong. Wood posts can shrink and loosen in concrete, at least with gravel you can tighten them up again. Gravel gets my vote.
*I've always used dry gravel mix concrete. It will set up eventually just from ground moisture. Get the post to grade first and approximately vertical. Pour in the gravel mix and don't let any get under the post. Put a level on the post and tap with a hammer to vertical. If water is convenient you can then pour a gallon or so around the post. Letting concrete get under the post will form a seal and expedite decay.
*Gosh, didn't we just talk about this about two weeks ago? Anyway, I'm in the gravel boat; I think it does a much better job at draining water down and away then anything else and is easy to use. And I have pulled rather "young" posts out that were set in dry concrete; always, always find powder, and I've also seen some yellowish crap on the PT posts where it's in contact with the powdered concrete. Tell you what, you guys do it your way, I'll do it mine; it would seem that either seems to have served all of us for years.
*A thaought comes to me. If you set a post in gravel only, will this not become dirt and gravel after a little time of water draining into the hole and carrying silt with it?Time and time again, concrete is the proven better way to go when done properly.Pete
*Pete,Does weeping tile fill up with silt?
*Tile has an outlet for the silt to go to. AA hole on the ground does not.Setting a post in a hole of gravel is the same as sticking your posts into a series of french drains. Doesn't make much sense when you think about it that way, eh?Pete
*Pete,Where does the silt go after it leaves the tile? My point is, if silt was a major problem we'd all have plugged weeping tile. Besides, post holes are at grade, tile's 4'down.
*Gravel is the way to go. Concrete and wood are not a good pair . Even on a dry day, concrete is moist. Gravel is only wet for a short period when water table is high or it is raining. Concrete cures away form the post, in a few days you can see gaps around the out side of the posts. great spot for water to drain into and never leave. If you go 3' deep and damp pea gravel they will be solid. Water will drain quickly away.
*Posted by Noel G.My original question was my first foray into "breaktime"and thanks for all the info and experience.This is awesome to just to hear you guys debate this stuff.Ron Rosa- thank you. I agree that overall gravel shouldkeep the posts drier, the "old" posts (a recent repair)that I pulled out had some rot in them, and they had beenset in concrete, even keeping in mind the guy did a lousy job,In my case( a flat lot ) I don't see why the holes willcollect much water anyway, and should drain/dry quickly.
*Noel, you have two issues to deal with: rot and stability. If you use treated posts, rot shouldn't be an issue, but to be on the safe side for your really nice fence, get the .6 treated posts spec'd for all-weather wood foundations--supposed to last fifty years below grade, or so i read.Stability is still best addressed with concrete, as the surrounding dirt will enter the gravel unless filter fabric is involved, which was not mentioned in comparing the French drain apples to the fence post oranges. I sure wish i'd done my second fence like the first...i wouldn't be straightening and concreting more posts in this spring.
*Noel,The CCA posts you said you plan to use are what Splintergroupie is reffering to as "all-weather wood foundation" lumber.
*Most CCA 4" x 4" posts are .40 (rated for ground contact). Splintergroupie was refering to the .60 posts, rated for IN GROUND use. These are the same type of posts used on all wood foundations, boat piers, and any other projects requiring the post to be buried.Another problem I see is locality. Here, our water table is so incredibly high that you don't need to do a percolation test in SOME places. You do not have to add any water and wait for it to drain out. All you have to do is dig the hole, and water will automatically fill it up. In this area, .60 posts, buried in concrete are the only way to go. Gravel will only give you temporary stability. In fact, the U.S. Post Office requirements for mail boxes here is that they be buried minimum of 24" in the ground, IN CONCRETE. No gravel is allowed. Evidently in the past, mailboxes had a tendency to fall over when buried in gravel only.Just a thought...James
*How about half and half on the gravel-concrete debate issue?Bottom half of gravel with a concrete cap to reduce infiltration and add stability...Best - Don
*Another great way to do this, it will cost more but what the hey. They sell a product called POST IT. It is made to pound in the ground and then slip in the post and screw through the provided holes. I have never used this . My thought was to sit these in wet concrete let dry then install the posts. What you boys think? The concrete cap Idea sounds pretty good provided you use at least 6 " of fiber mesh concrete and make the hole at least a 1' circle. The 4" around the base you first mentioned would not be effective with any of these installations.
*Ron,Are you refering to the brackets that have a spike on the bottom that you bury in concrete and the post sits in the square cup on top that is about 3 or 4 inches deep? If so, that would not work for posts of a fence as it lends no lateral stability. those are intended as bases for posts on decks where the deck structure gives the posts lateral stability.Pete
*We dig a hole 1' deeper than the set depth, fill the bottom foot with gravel, set the post on the gravel bed, and then tamp road pack around the post.I don't know if road pack is easy to get everywhere, though. We live a few miles from a limestone rock quarry, they call it C6 road pack, and it's basically unwashed gravel. When the stone is crushed it goes straight to the pile without siftng or washing all the fine powdery crush away.The crush fills in all the voids between the gravel and it sets up almost like concrete. Any water that drains into the hole drains right out again thru the loose gravel base under the post. Just be sure you like the post where you put it, they're a bitch to get out!
*I would guess that's a lot like Metpost System-2, which is a drive-in spike about 30" long with a 4x4 clamping box at the top. Metpost also make concrete-in and bolt down versions. They also make a repair "spur", which drives into a post stump set in concrete so that you can put a new post on top. I've only seen a couple of drive-in installations, and they looked okay; but, they had firmly set in concrete corner posts and were short runs.
*
Installing a very nice custom fence and would like the new cca posts
to last. Instead of just backfilling with existing soil, a brown
loamy stuff with little or no sand, I plan to set them in gravel
approx. 4" wide around the post and at base. The guy who sold me
the gravel thought this would be an invitation for water to fill-up
around the post, defeating the purpose. Also have heard some swear
posts last longer set in concrete, although I never do except if
posts are hanging a door or gate.
Any veteran post/fence people out there?