I am doing an arena fence, with 4x4’s on 8’ centers, with a top rail, foot rail, and middle rail. The rails will be 2x6’s.
I will hire a post hole digger, who wants me to mark the spots for the post holes. I can make him a nice line of marks on 8’ centers, but what if I am a little off? I want to buy my rails in 16’ lengths, and how accurate do my posts need to be?
Would it be better to space the post holes a little closer than 8’ centers, and plan on cutting the rail boards to size?
Personally I’d go with the 8’ centers. Most 16’ boards have up to an inch extra on them. If you need to you can always alternate an 8’ section of you have one set off kilter a bit. If they’re driving the posts then they will be off here and there anyhow. Not much you can do if you hit rock. If it’s an issue you could potentially go with sawmill lumber cut to your preferred lengths. Some can finish and kiln dry for you. Or just set your posts a couple inches closer. A lot will depend on your ground conditions and how the posts are set
I’m in the process of installing posts and am making all of mine spaced at 7’ 6" +/- 3" depending on the total run length. This will make it so I have to cut each board but there is no way the post holes will always be exactly 8’ apart and all your posts exactly level. You need some wiggle room.
Keith
Around here, using 16’ rough oak boards, I think most folks set posts at 7’10" on center. Chainsaw is part of the basic equipment.
And the boards are offset on the posts. Top board and bottom board begin on one post, middle board begins on the next one so only two ends are on any one post. This stabilizes the posts and makes the fence stronger. (Yes, you end up with a half-board somewhere, usually at a corner.)
Thanks all. It’s an arena, so I’ll run my string line. Then, cut a 7’9" length of wood, and use it as a template to mark my post holes for the digger.
This comes down to how much extra money you want to spend. In the mid-Atlantic area oak board fencing pretty much rules. The standard 6X16 ft oak fence boards are at least 1+ inches over 16. Right now they are selling for a bit over $10 each. Up $4 since my last fencing project a few years ago.
Just about all fencing in the area is nailed to 4X6 pressure treated pine posts. At present my fencing supplier is selling those for $14.30 each. At least 10% is knocked off for large orders.
4X4 work but they only have 3 1/2 inches of nailing face to work with. 1 3/4 to each side. Verses 2 3/4 on a 4X6. Makes a big difference and gives you 1 more inch of wiggle room. Also because there is more nailing room to use a 3-4 “box or V” nailing pattern. Holds the boards much better than can be had on a 4X4 and the boards tend to warp a lot less.
4X4 can and do snap a lot easier if a horse runs into the fence line. 4X4 require a LOT more tamping to get them held fast and not shift over time.
If the ring is 200X100 that is 600 feet of fence line. Divided by 8 75 + the starter post, 76 post needed set at an 8 foot spread. If set at 7-9 you are loosing 4" at each post. If my math is correct you will need 25 extra posts.
Cutting off 4" from each board means you will need 38 extra boards. (based on a 3 board fence line)
So the additional cost will be
38 boards at say $10 per, $380
4x4 pressure treated post go for around $9 around here. X 25 posts $225
So that comes to $605 in additional material expenses. If one was fencing several acres this way they would incur a LOT of additional expense
Verses take additional time to layout your post holes accurately.
4x4 post set at 7-9 with 3 boards cost to around $2,400 for wood materials
Using 4x6 set at 8’, 3 boards comes to around $2,370
Less work, IMO a better looking fence and a more long lived and secure fence.
When laying out a fence line I use a 300+ foot reel tape like this
https://www.harborfreight.com/330-ft…ape-62413.html
I set the first post and securely tie/nail it to, run it out and pull tight along the ground and tie to an end stake. I use ground marking spray paint. It is made to spray “upside down”. Walk along the tape and mark my holes. No big deal if you spray the over the tape it’s still useful for other things, like measuring jump lines. It only cost $15-$30 anyway.
When setting the posts I check for plumb, (plumb is a vertical line, level is a horizontal line) using an inexpensive post plumb tool like this.
http://www.homedepot.com/p/Oz-Post-P…0740/202400878
I only use spiral shanked 16p nails. A lot of nailing by hand. I have nails guns which makes the job MUCH easier and faster. These can be rented and IMO worth every penny. Easy learning curve. Just don’t shoot yourself in the leg or hand. I “pinned” my hand to a board while building a house years ago. Makes for an interesting visual lol.
We just had a post and rail fence put in, and I think they made the holes as they went along, more or less. That may have been because we have lots of boulders hiding under the ground, and putting them in advance at 8 ft would have been dicey.
I am in your area. I helped a friend with her fence. By far the majority of the boards were exactly 16 feet. There were a few stray ones that were a touch longer.
She had already marked the holes and we had augered about 1/2 of them before the boards were delivered. It was an issue on some. I would confirm with the seller are the boards a true 16’ or not. Or wait until they are delived so you can measure them before digging. I wish we had dug the holes at 7’10" it would have made things so much easier. I personally would not go a true 8’. You can always shorten the board, it is much harder to make it longer. That 2" or 3" inches gives you that little bit of leeway. Yes it is potentially more work to cut them but trying to stretch boards or having them barely on the 4x4 was tougher. I know at least 2 of her 4x4 has a 2x4 splinted onto it to make it work.
What, you couldn’t find a board stretcher on Amazon?
Interesting, were you using rough sawn oak, “dedicated” fencing boards ? I’ve been buying/installing oak board fencing for years and have never bought/used board that weren’t at least 1+ inch over 16 pretty much always 2" over.
Getting ready to put up some more in the near future. I just talked to Lapp Lumber in Paradise, PA they have the best price that I have found so far. 8.96 for 16 foot oak boards and they are 2 inches over 16 foot. I also buy from Esch Fencing in Gap a few miles on Rt 10 north of Rt 30. The oak fencing boards they sell are always around 2" longer than 16. Both supply to horse farm fencing contractors that insist the fence boards run longer than 16. This “rule” has been in effect since I was a kid in Md.
Even with using the standard 16-2 boards laying out a fence line using 4X4 post can be challenging. As I said in my previous comment you only have 1 3/4 wiggle room. Verses 4x6 that gives 1 inch more wiggle room. I’ve never had to “splint” scab a nailer on a 4X6.
Other than the added expense from wasting material and the extra time and labor of cutting the boards shorter. There’s nothing wrong with setting thin post closer. If you’re not putting up a lot of fencing no big deal. But I think the numbers I posted as to how much it adds to the cost are self explanatory. And or the rule of diminishing returns with the add labor of having to cut each board to length.
I really like using oak slip board and really like the look. These are set at 10’ and 12’ boards are used. With a foot over lap there is a lot of wiggle room. But slip board is more expensive and sometime the slip board posts are hard to find.
I suppose if I were using 4X4 post and didn’t have a lot of experience with laying out posts and drilling them. I would still lay out and mark the holes at 8 foot spacing so as to have a “line” to work with. Set my first 2 posts and lay the board out for the 3rd post and drill the hole based on where the board ends. Just keep moving the tractor along and drill every "3rd hole as I go.
But I would only use 4X4s if I HAD to. Experience has taught me why, lol. To each their own on this.
Your math is off.
600 feet of fencing with 8’ spacing is 76 posts and 228 boards for 3 rail.
600 feet of fencing with 7’9" spacing is 79 posts and 237 boards for 3 rail.
Going to 7’9 spacing you need 3 extra posts and 9 extra rails.
The difference is a lot less than your original calculation. Using your price for posts ($9) and rails ($10) the cost difference between going 8’ vs 7’9" is $117, not $605.
Keith
Thanks for checking my math. I thought it sounded/looked high when thinking about it later in the day. Not sure how I came up with those numbers.
I don’t know where she bought the boards and the posts. I was only helping install. None of us had ever done board fencing. DH and I had done a lot of 2x4 no climb with and without a top board. Mostly without. Wire is much more forgiving. Therefore we had the most experience of anybody. DH is also pretty handy.
We could not drill and put in the posts as we went since the Bobcat had only been rented for 2 days. She was only putting in about a 4 acre field- sorry I don’t know linear feet on that. So it wasn’t really a huge project in some ways but it was July. It was going to take more than 2 days with the crew we had to tamp the posts let alone tamp and put up the boards at the same time. We went through a huge amount of Gatorade every weekend in July.
My personal preference would have been larger posts and have somebody drive them. Limited or no tamping required. She does not have many rocks on the property so driving could be done easily. (I used to live in Elverson where driving into the boulders that are there just doen’t work out real well).
But I wasn’t paying for the project. My guess is that the 4x4s made the project much more affordable than 4x6 or than driving bigger posts. But the fence is in. It looks decent, is sturdy and keeps the horses in. One line could be restood up straight on a numer of posts and retamped. That side of the property is really wet so I think some of the posts heaved a bit. A number of those posts in the back on that line filled with water overnight after they were drilled. We put concrete in a few since they were so wet. The posts might not be perfectly verticle but you have to stand in just the right spot to really notice. Would I do things differently if I ever put in post and board again? Yes I would. I prefer 2x4 wire with top board myself so hope I never have to do post and board again.
The 16’ rough cut treated pine fence boards you buy around here are almost all exactly 16 ft in length. I set posts 7’10" apart. Yes, I have to trim some, but it’s a lot easier and less wasteful to do that than to have to cut 8’ 2" lengths out of 16 ft boards to fill a gap that ended up a little bit too wide.
I’m not precise enough with a chainsaw so I use a battery powered circular saw to trim.
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