The Case for the H-Brace

I have been doing a lot of reading about fencing design. I checked out about a dozen books on fencing from the library, but found them all to be inadequate in their treatment of non-decorative, practical fencing for livestock. So, the “Interweb” (as Kirk likes to call it) helped me a lot. These nice folks at Gateway Farm Alpacas have the best advice, by far, that I have found for installing field fencing, which is the  type I chose to use. I also found good help on the websites of fencing manufacturers, with installation instructions for their own products.

It occurs to me that perhaps the most important component of any fence under tension is the end-bracing. Granted, I’m not doing a high-tensile fence, but field fencing still takes plenty of stretching to make it strong and non-saggy. I have come to realize that there isn’t a lot of good advice out there about designing end-braces, or the “why” behind the design. And as I drive through our county, I see many more examples of failed end-braces than successful ones. So, after a lot of reading, studying other people’s mistakes, and thinking, here is what I’ve concluded on the end-brace debate. Now, I’m no mechanical or civil engineer, I’m of the electrical bent; but I did have to take a few ME and CE courses in college, enough that I grasp the basics of statics & dynamics, and physics. So, here is my stab at explaining what happens to end-braces, why they are prone to failure, and how to best ensure their strength and longevity.

The first step is to think about what is happening to the end post on which multiple horizontal wires are pulling. The most concerning point is near the top of the post, due to torque (think of a long lever…), the force on the post is greatest here. The post, especially if you didn’t bury it really deep, is going to want to “flip” sideways out of its hole. This is because the bottom isn’t going to experience enough resistance from the soil to counteract all that force on the top of the “lever.” The soil is going to “give in” and erupt vertically, allowing the post to migrate and eventually lean, which allows the fencing to become slack at the top. This will mostly likely happen very slowly over years; though I have heard of it happening to people the instant they tensioned the fence, if they did an especially poor job of brace design! Here is a picture of what this lever action looks like:

Additionally, the post is also going to want to bend, because its tensile strength is being challenged. This part is easier to address by using very thick (usually 6″x6″) posts with no flaws, which offer greater tensile strength. So, that just leaves the leaning tendency to fix. There are many solutions people offer to address this problem. But I feel the most practical and wisest solution is the “H-brace.” The idea is to transfer most of this load to a second post, and allow that post transfer the load back to the bottom of the first post, offering a counter-force. So, first let’s focus on transferring the load to the second post:

 

By putting a horizontal beam in between the end post and second post, it’s easy to see that much of the load on the first post will now be pushing on the top of the second post. But, this, by itself, is no help; because of course the second post is now going to want to “flip” in a clockwise direction too. What’s needed is a diagonal wire wrapped around both posts, tied back down to the bottom of the first post, and then tensioned, to transfer the load back down to the bottom end of the “lever.”

Above, you can see how the diagonal wire is going to pull on the bottom of the end post as a reaction to the cross-piece pushing on the second post. Physics 101 teaches you how to break down a diagonal force vector into is horizontal and vertical components (F1 and F2 in the diagram). You can do this mathematically using trigonometry, but here I’m just going to show it intuitively, the precise math isn’t as important as the general concept.

The goal is to create a “long” triangle as above, where the wire is pulling more in the horizontal direction (F1) than the vertical (F2). The vertical component of force (F2) is actually undesirable, because it’s going to encourage the post to pull up out of the soil, so we want that to be as small as we can manage. What we want is more F1 force, which will counteract the lever action happening at the top of the post, pulling it at the bottom to make it stay standing up straight.

The mistake many people make is creating too narrow of an H-brace, so that their diagonal wire has a very steep angle, instead of a very flat angle. This means there is more upward (F2) force than sideways (F1) force, so over time, the end post could possibly pop out of the ground from the vertical strain. The rule of thumb I’ve read is that you want angle no bigger than 45° from the ground, and preferably less. So make your H at least twice as wide as your fence is tall, though 2.5 times as wide is better.

The reason H-braces are the most popular method is that they are the easiest and cheapest to install. Merely:
1. drill holes for, and then pound in brace pins (foot-long rebar works well) to secure the cross-beam (you can notch the posts too, but it’s extra work, and doesn’t gain much),
2. use a heavy gauge wire for the diagonal, securing it with staples top and bottom (or you can hook it over a sticking-out brace pin at the top),
3. then tension the wire by twisting a “twitch” stick in the middle of it (or use a new-fangled, store-bought tensioner device) until its firm.

One alternative method to the H-brace is an “N” shaped brace. It involves making a diagonal out of another beam, that travels from the top of the end post down to the bottom of the second post, so that as the end post wants to “flip”, it’s pushing against a diagonal brace that resists this motion. The theory is good, but I think this method is less practical because first, you have to buy an expensive, long post to make that diagonal (a 10- or 12-footer for a 4′ high fence), rather than letting inexpensive wire be the long component. And, it’s more challenging to truly secure that diagonal to the end points, so that things won’t just “scoot” around, or cause nails to pop, when forces are applied. You need to do a fancier job of notching and securing, which is often inconvenient when you are way out in a pasture without power and your whole tool box. Wire is a lot easier to secure than an angled junction between to beams, especially for laymen.

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I’ve often seen examples of braces where someone put the diagonal wire in the wrong direction. This actually has zero affect long-term, because as the end post starts to lean, it’ll slacken the tension on the diagonal wire, such that it starts to do absolutely nothing. But when first built, the moment the diagonal wire is tensioned, it’s actually going to put more force on the top of the end post, causing it to want to lean more than ever! In this case, the only saving grace of the “H” is that the load is still shared between the two posts, which is better than nothing at all; but it’ll probably still fail over time.

Another mistake I’ve seen is people putting diagonal wires in both directions, and then tying them together by twisting the twitch stick in the middle of both. If you feel you must do two diagonals (which makes sense on an H-brace that’s mid-run on a long fence line, or if you have a gate pulling on an end post in the opposite direction of the fence tension), they must be independent of each other, so they can each counteract their own forces. If they are tied together, you are crippling the one that’s experiencing the most load, and transferring loads to places where you don’t want them. As you can see from the diagram below, there are 14 different force vectors to worry about, that are all influencing each other- way too complicated to get it right!

 Connected diagonals in an H-brace

Here is how one of my H-braces turned out; I used 8’x6″x6″ treated timbers here for the posts, buried about 3′ deep; and a 8’x4″x4″ as the cross-beam, tilted slightly so water will run off it. The fence in this case is running off to the left. This brace is enduring quite a slope change; sometime maybe I’ll go back and cut off the second post a little shorter for aesthetic purposes to make it match! These seem to be holding strong, so far, under the tension of the newly-strung fence, knock on wood!

 

0 thoughts on “The Case for the H-Brace

  1. Roger Gehring says:

    I don’t see why you cannot purchase pre-built brace and end posts and then install on your property. I agree that it is so important and difficult to find someone to do it, if you need to have it done. Any ideas on this?

  2. workingcollies says:

    Roger, that’s a good question. I have not seen pre-built braces available in my area; but maybe they are out there. The only challenge I can see with installing them pre-built is that then you have to carefully dig the holes, like for a gate opening, to make sure they are spot-on both front-to-back and side-to-side. Hand-building your H braces, you can fudge a little bit on the side-to-side measurement, and then cut the cross-beam to fit. But, they are time consuming for sure, if there is a quicker way to make them, I’d love to know about it!

    I will soon be trying out the Wedge-Loc braces on a small piece of fencing I’m going to build, I’ll report on how those go. I found a local feed store that carries them, and the owner said they work well for short sections of fencing, and that he sells a lot of them.

  3. Clay Nash says:

    I would have to disagree with you. I own and operate my own fence company and have and never will build an H brace. My Grandpa ran cattle in the mountains of colorado on about 18,000 acres and he built about 250 miles of fence in his lifetime. That is comparable to 600 or 700 miles in the flatlands. I started building fence when I was 12. I am now 28, needless to say I have built hundreds of N braces. I guarantee my corners to never move for the life of the wood, and they do not.

    The H brace relies on a wire to hold the fence, this does not work. There is too much pressure and stretch to stop the posts from moving. You have to get all the stretch out of the wire in order to use it for brace wire. I use old oil rig drill stems in 11 foot sections for my brace, so the weight or pull of the fence is being supported by the drill stem. There is no stretch or give in that.

    The issue of too much money for a long brace or being able to secure the brace properly does not hold water. I have much better technology then my grandpa did, but the braces he built in the 50’s and 60’s are still there, and he had a ax, handsaw, and hammer. As far as the money goes my drill stem or a big 16′ pole is dollars more expensive than a short brace, but will last years longer.

    I was taught how to build fence from my Dad, Uncle, and Grandpa and between the three of them they have more than 150 years of knowledge. I have hundreds of miles of fence throughout Colorado as proof that N braces work better, some built in the 40’s, some built yesterday. Feel free to visit my website at http://www.nashbrothersfence.com. By the way, I enjoyed reading your article.

  4. workingcollies says:

    Hi Clay, thanks for the comments. I usually don’t allow business advertising on my blog; but I let your comments go through because I think you have some helpful info on your website even if someone didn’t hire you to install their fence.

    I am inclinded to agree with you that the N brace, the way you do it, is probably the best and most long-lasting design, especially in dryer climates. I can’t see from the photos on your site how you are attaching the diagonals to the posts, but it sounds like you notch them. I think this is the critical piece of information, is that the joint has to be really good to prevent the diagonal from slipping over time. I’ve seen very few attempts at N braces in my region, but the few I’ve seen, they tried to use nails, or very shallow notching, and I would be concerned that the diagonal would just “pop” in time.

    My only comment was that I think these braces are harder for laymen to do, and also more costly, thus the reason most people choose the H instead.

    I agree that the wire stretch is an issue with the H brace (though it looks like you still also use wire in your design to snug the verticals together opposite the wood diagonal?). That’s the job of the twitch, though, is to allow you to tighten it periodically if it starts to slacken. And, the wire will definitely not last as long as a wood diagonal. I considered the N brace for these reasons, but decided that in our region, where it’s SO wet, that probably the first thing to fail on the fence would be the wood posts rotting anyway. So, the cost savings and ease of installation won out for me.

    I wonder, too, if fencing design doesn’t have regional styles or fads? Almost everything in my area is an H-brace, or botched attempts at H-braces. I’d be curious to see if that’s true in other parts of the country, however.

    Interesting discussion, I definitely wish there was more written about this subject!

    Michelle

  5. MMP says:

    This conversation occured a while in the past so you may have moved on to other things. But I am going to put in my vote for a modified N system. I haven’t put up a lot of fence like Clay, but I have formed an opinion.

    I have goats and use a 5 wire fence to keep them in backed up with a fence charger. It works pretty good with the exeption of young kids small enough to slip under the bottom wire. And I am putting up an 8 wire deer fence for our new garden away from the house.

    My corneres consist of the corner post, a brace post, a diagonal and a horizontal. I knotch them to hold and pin with 1/2 rebar pins. Compared to an H brace, it does use more wood. But a fence that falls down costs more than posts. And I don’t like using a wire for tension.

    Anyway, I just got done posting about doing the corner posts for our deer fence.

    -mmp

    • workingcollies says:

      MMP, I think you have a good point-comments always welcome, because I never stop thinking about fencing and noting how others have done theirs everywhere I go! I think N braces are very strong, as long as they are properly installed and it sounds like you do them very well. I may still consider doing them that way in some spots, I’m tempted by the idea, and it might be fun to see how they perform compared to the H-braces.

      It’s interesting, I’m not sure that I’ve seen any N-braces in my region (almost everybody here uses H-braces, and about half of them installed backwards!), so I wonder if it’s a regional style thing? I think too, where I am in the rainy northwest, probably the first thing to fail is the posts rotting, so I bet we never get more than 15-20 years out of a fence anyway! :-{
      Michelle

  6. Scott says:

    I’d love to find a source for oil rig drill stems here in the Pacific NorthWet! I wonder what a truckload would cost, or where to stop by with my trailer the next time we’re on vacation?

    I started fencing here (about an hour East of Seattle) about 15 years ago using the H-post system, and am starting to see rotted posts (treated 4x4s set in concrete). Sometimes the water level here on the side of a hill is about 2″ below ground. Also the wires fail from time to time; initially I was using too small of wire.

    I’m looking into concrete fence posts, especially for the end posts. While looking for concrete fence-post plans, ran across a Google book “Farm Concrete”, (c) 1917, free for download. It has a chapter on concrete fence posts, including large end-posts with ‘legs’ which would replace H-braces, plus sections on cisterns, silos, etc. etc. Well worth a read!
    http://books.google.com/books?id=ikdDAAAAIAAJ&printsec=frontcover&dq=farm+concrete&ei=STcfSp7PI4KszgSwsd2uDw#PPP1,M1.

    I’m thinking about line posts 5″ x 5″ at bottom, 3″ x 3″ or 3″ x 5″ at top, with ‘keyed’ replaceable(?) wood nailing strips cast in. Per the book, 1/4″ rebar seems the best reinforcement. Hopefully concrete’s gotten better since 1917, so the curing time won’t need to be as long as specified in the book. Plastic sheet on the plywood form bottom to keep moisture in, possibly a metal form instead. Not sure what to use for separators between posts when casting them. Maybe just strips of plywood or OSB, wrap it in plastic-wrap to ensure separation? Suggestions, anyone?

    Best regards,
    Scott

    • workingcollies says:

      Farm Concrete- I love it! It seems you could make a lot of useful homemade things for cheap using concrete! I wonder how much tensile strength a concrete post has compared to wood? And how heavy they would be? The 6x6x8 treated posts are about all I can handle, especially when I find I drilled the hole crooked, have to do hand-digging, and lift the post in and out several times before I get it right. They are especially hard for me if they are newly treated and still soaked with moisture–oof, they are back-breaking! Thus I was slipping in some 4x6x8 posts on shorter lines; they worked ok, but a couple of them slid a bit- the extra couple of inches must make a difference in both strength and difficulty moving through the dirt!
      Michelle

  7. Nick says:

    i am in the process of building a small braided wire fence pasture (100′ by 50′). I have put 8′ by 4″ wood posts every twenty feet and a metal T post between every wood post. As far as corner bracing, I am unsure what to do. Are h braces the way to go for such a small pasture? If so, is there any reason i can’t use a T post as a brace post so long as i can find a way to securely attach the crossbeam? I am trying to minimize the amount of holes i have to dig for wood posts because i dig all of my holes by hand. Thanks!
    -Nick

    • workingcollies says:

      Hi Nick
      I think you do have to do some kind of corner bracing, because if you stretch the wire at all (or if animals even push on it or ever run into it) there will be tension on the corner post that will try to pull it out/over. But, for such a small run, I’m sure you can come up with something less massive than the 4×4/6×6 wood post method. I bet Wedge-Loc brackets would work for you, to make your corner braces entirely out of T-posts. I am planning on trying these for a small area I need to fence around our drainfield- I think it looks like a good invention. I have used the Wedge-Loc brackets for making little shelters, and they work pretty cool. I don’t think they are any cheaper of an option than wood, but definitely less effort and you can take them apart easily if you ever change your mind (or if you decide later you want to put in wood braces in their place). I ordered some of the Internet, but then figured out later that several farming supply stores around me carry them – I’d just never noticed them before! I asked the owner of one store, and he says he sells quite a few of them, that a lot of his clients have had success with them.

      Good luck! Michelle

  8. Chris Young says:

    I have my own ranch now and I need to redo all of my fences so I decided to see if things are done differently these days so that how I found this web sight.
    I cowboyed for 3 years in North Eastern Nevada (Elko County) and the old Cowboys taught me to use H and N braces together for long stretches of barb wire fences and always used railroad ties.
    Some of the old H and N braces still had the narrow gauge rail road spikes and tie plates still in the ties from the old Eureka-Palisade railroad line that ran through the ranch more then 100 years ago. The tension wire I think was the old one party phone line that serviced all the ranches way back then. Still tight and sturdy. Most of the barb wire has been replaced but lots of it is still has the old diamond shaped barbs on the wire from the late 1800’s.
    Chris

    • workingcollies says:

      Chris, that’s a great illustration! What led you to choose a combo of an H and N brace, versus doing a double H or a double N brace? Do you think the wire on the N brace is necessary? It seems to me that since it’s strung in the same direction as the load on that brace, that initially, it will slightly counteract the intent of the N brace, but then over time, would “lose” the battle against the wood bracing and would just go slack and not add value?
      Michelle

  9. Gage Edgar says:

    I am a boy scout working on an eagle scout project. For my project I am going to be installing a four foot tall woven wire fence at a state park in South-East Wisconsin. I found a product called quik braces that will allow me to install N braces without having to notch the posts.

    I read this article and found that the ideal H brace length is 2.5 times the height of the fence. I’m wondering what is the ideal length of an N brace compared to the fence . Would it be 2.5 times the height of the fence, or would the distance between the end and brace post be 2.5 times the height of the fence? In the first case
    case it appears that I will need to use the pathagorean theorem to find the distance between the posts before I mark the posts.

    • workingcollies says:

      Hi Gage! So I think you are right, that the same rule of thumb applies, that the width of the brace should be at least 2.5 times the fence height. The same principle applies whether it’s an H- or a N-brace, that the “middle stuff” is meant to transfer some of the load horizontally onto the 2nd post; so if that “middle stuff” is more vertical than horizontal, it’s not transferring enough of the forces in the desired sideways direction. And yes again, the Pythagorean Theorem would guide you on how long to make the diagonal post. So for a four foot fence, you’re likely stuck buying a 12′ diagonal beam. You could maybe cheat and use a 10′ diagonal, it would be close to the rule of thumb and would save some money. But in theory, the wider the better for braces that need to last a long time.

      I recommend not cutting the diagonal until you get the verticals up. Get your Quick Brace brackets on, then measure and mark the diagonal and cut it to fit. I have found that it’s really hard to get the vertical posts placed exactly where you planned, so it works better to cut the middle members afterwards so they fit perfectly. I checked out those Quick Brace brackets, they are pretty cool, I’ve never seen them before! Thanks for sharing and good luck with your project!
      Michelle

  10. Steve Hawkins says:

    I’ve built a number of fences doing ranch work in the summer, and your information is spot on with a good explanation of the physics. I don’t think we made out cross beam 2.5 times the height of the fence, but then we usually set our posts at 3 feet deep and tamped them well. Tamping the post right, especially the bottom half, is crucial to having solid H braces. I would not argue with Clay about N braces. His experience obviously validates their use. But I would agree with the other posts that in the Northwest the wood will probably rot and fail before the wire on a good H brace. If the diagonal wire is put on as tightly as possible before twisting it, you can get a good tight wire that will stretch very little. Doing additional tightening after the rest of the fence is built is a bit tricky, but possible.

    I would add that on a very long run, we often put in a double H brace to add strength. Also, any significant rise or drop meant a double H brace at the top of the rise or the bottom of the draw and any change in fence direction, even like a 10 or 15 degree turn required a double H brace. It meant more work, but the fence would then be pulling straight against the brace posts and not sideways against the metal T posts.

    I think for the average person, the H brace is easier, but for someone with lots of experience, the N brace might be a possible alternative.

    • Michelle Canfield says:

      Gene, I don’t know very much about locust because we don’t see it sold here much, but I think I’ve heard it’s a good wood for fencing? 12 food wide for the brace is definitely good for a fence that’s 4′ high. But were you thinking of using a 2″x6″ board for the cross piece? I know I tried that once on a very short section of fence and it didn’t work well- the board is willing to bend, so it just bows under the tension between the posts. I had to compensate by putting another post underneath the middle of the cross-piece, and tying those together to make it be stiff. So I think it’s best to use a beam as the cross piece- either a 4″x4″ post, or a 4″ round post. Hope that helps!

      • Gene Mack says:

        Michelle
        Thank you for your reply I should of told you the runs I am making using the 2×6 are not more then 70 feet.I will use 4×4 now after taking to you with the longer runs. Bought wire today want to get some fencing done before the cows start freshing and the snow gets to deep. Will let you know how the 2×6 worked or I have to do it over.
        Gene

  11. Michelle Canfield says:

    Gene I think I might not be envisioning right what you are doing- are you using a 2×6 board for the “middle” part of the H brace, or for something else? Did you notice if it bowed when you put it under tension stringing the wire and tightening the diagonal wire? Let me know how it turns out!

    • Michelle Canfield says:

      Matt, it has worked well so far- I only used them in places where there was a very short section of fence, so there isn’t a huge amount of tension on them. But they have held up for 2+ years.

      • Matt Stonecipher says:

        Thank you for your reply. The Wedge-Loc components that I ordered from Kencove Fence Supply arrived Monday and will be installed Friday and Saturday. The area I am fencing is slightly less than 1 acre in the shape of a square so I do not believe there will be any length of fence longerthen 200 ft. or so. Many folks have had positive comments on the system but there has also been a few less than impressed in my search as well. Time will tell for me.
        Thanks again.

        • Michelle Canfield says:

          Matt, I’ll be interested to see how they work for you on that long of a span. Are you just using the Wedge-Loc brackets and a t-post for a diagonal, or for the whole H-brace? My guess would be t-posts for an entire H-brace won’t be strong enough for that long of a run. I would at least make sure you use as long of a t-post as you can get, and make sure the runs are perfectly straight, so there is only one direction of tension on the brace. I suspect they’ll have a tendency to twist and buckle if there is a lot of tension, and it’s not perfectly parallel to the alignment of the brace.

          I’ve only used them for really tiny sections- maybe 20′ wide at the most. I have some weird fields sections with curved corners, so that’s where I’ve used them, to brace a short section between two wood H-braces. For longer runs, I’ve discovered that even 4×6″ posts tend to move in the soil more than 6×6″ posts, so I’m guessing a t-post will just “give in” to the tension completely. This may not be critical though, I think a sagging fence is mostly an aesthetic problem, not a functional one, as it still keeps in cows and sheep…

          • Matt says:

            I will be maing “N” braces as corners rather than “H” braces. I have used the “N” brace in the past with great luck using wood posts. I will be using 8′ t-posts in the corners and the literature I have suggests alternating the direction in which I wrap the wire around the corner post to prevent it from twisting the post along with starting with the bottom strand first rather than the top strand like I have done with wood posts. I will report back on the installation over the weekend.

  12. yahoo says:

    Michelle
    After reading your thoughts on H braces,I took down the 2x6s and put in 4x4s treated with the pins through the post which I am glad I did. For if I wouldn’t have the 2x6s would have surely broke under tension.
    Thank You!

  13. Michelle Canfield says:

    Cool, Matt, would love to hear back how they work for you, especially over time. It sure seems easier than wrestling with wood posts, if the longevity was there, I’d be into that!

  14. Clyde Wray - owner Aspen Fence says:

    There is an excellent video available from Keystone Steel & Wire, manufacturer of Red Brand Wire Products for installing “H” Bracing. http://www.redbrand.com http://redbrand.com/InstallationVideos/Default.aspx I am a Fence Contractor located in Haymarket, VA. My primary business was residential fencing. However, I began to receive calls for Farm Fencing. I decided to investigate the different types & styles of fencing utilized in my area. There is a lot of Paddock Fencing as well as Wire fences in my area. I did my research as I wanted to make sure I was delivering a quality product that would last years. I contacted Red Brand and had lenghty discussions with Ken Edwards at Keystone. He is a wealth of knowledge and their site offers great videos for proper installation of fencing and the importance of proper bracing including “H” bracing. Just wanted to pass this information along as it has helped me become a premier Farm Fence contractor in my area. The videos are well produced and easy to follow even for a DIY.

  15. Dieseldan says:

    I have put up several high tension 6 wire barbed wire fences and and have found the “H” System to be the best. What most people fail to understand is that you are trying to prevent the corner post from pulling up or leaning over. The “N” system tends to pull the corner post out of the ground. Just think about it. The brace acts as a lever creating an arc which will pull the corner post up in an arc. The next brace which is not a true “H” brace is with the brace at the top. Basically with the brace at the top the forces are equal on both of the two posts. Both posts will eventually lean over parallel to one another and then fail.
    What I have found to work the best is a true “H” brace. The brace should be parallel with the ground about as high as you can step. About midway to the top fence wire. The “H” is tensioned together with wire across the post in a diagonal opposite the way the “N” post brace works. From the bottom of the corner post to the top of the brace post. Using the barbed wire or other high strength wire I wrap the wire around the top brace post one time and nail on. The wire is then ran to the bottom of the corner post and nailed and back to the top of the brace post. I run it around twice. The wire is then wrapped around the brace post twice and nailed and cut.
    The cross wire is then tensioned. What I found works best is 1/2″ galvanized pipe (does not rust and extreme pressure can be applied.). I drill one small hole in the end for a galvanized nail. The end of the pipe is just barely put between the wires somewhere in the middle and the wires twisted. This will basically double the tension on the corner post. The brace posts acts as a lever since it is in the middle. Once tightened to maximum tension lock off the pipe against the center brace and put the nail in the pipe to hold it in place.
    I have actually seen some of my brace posts bend over the years from the pressure exerted and the corner post is still straight up and down.
    I never notch or drill the posts. That weakens them. The cross “H” brace post is notched in a “V” which wraps around the two main posts.
    The cross brace has so much tension on it that no nails or post notches are needed.

  16. Michelle Canfield says:

    Dieseldan- it’s an interesting concept, putting the horizontal brace halfway down the post instead of near the top. It would definitely change the the angle of the diagonal wire, reducing the upward “lift” force on the end post. But it also seems to add a new fulcrum point in the middle of the end post, which intuitively seems undesirable to me- that it creates a new lever action that encourages the post to pull out of the ground again? I’m not sure what the net effect of the two changes together would be to the overall design, I think someone would have to do the math to figure it out for sure.

    I think the biggest key with any of these braces is the width dimension- if people make an H or N brace too narrow, then the diagonal wire/brace will be putting too much upward force on the end post, encouraging it to pull out of the ground. The wider the whole brace is, the more that diagonal angle is flattened, thus reducing the upward force.

    Probably soil type and whether or not concrete is used as a footing on the post impacts the need for a wider H brace. We have pretty dense, mucky soils here, and often rocky as well. So I think people in our region get by with a lot of mistakes in brace design, and the soil still holds the post and doesn’t allow it to pull out. But I’m imagining that people in places with dry, sandy soil need to worry more about the post migrating upward as it leans. Then it would be critical to make sure the brace is as wide as possible.

    • Chris Young says:

      To get around the point of the horizontal being to low or to high this is what the old cowboys taught me.

      On making H braces I always make the vertical post 2 1/2 times wider then the height of the horizontal post. example: If the horizontal post is going to be 4′ off the ground I space the vertical post 10′ or more.

      My H-braces are made of Railroad ties with the vertical being 5″-6″ round pressure treated post. When I was making a living as a Cowboy in NE Nevada 12 years ago, the ranch still had H-braces made out of the narrow gage railroad ties that ran through the ranch 100+ years ago. Some of the H-braces still has the narrow gage tie plates and spike still on them.

  17. Scott says:

    Using high tensile wire for your diagonals when constructing H braces will eliminate the possibility of stretching if your fence corners are far out in the field and not in an area that can be periodically adjusted. Otherwise, like most things, fences need maintenance and H braces which are properly constructed and maintained can be self installed without you having to be professional fence builder who does this every day.

  18. Jen M says:

    Updates on the WedgeLocs? I have a bag full, waiting to be implemented. One set for dog yard, and one set for a 152′ run of ‘horse fence’. Anxious!!

    • Michelle Canfield says:

      Jen, I like them fine, the braces I’ve made out of them are still standing straight 3+ years later. I had made a shelter out of them and t-posts too, and that actually did fall prey to a weakness- somebody dinged one of the posts with a mower. The shelter cannot handle any twisting kinds of forces like that, so it torqued it and made it fall down. Which wouldn’t happen with a wood post structure so easily. But I do think they are fine for braces.

  19. Rob says:

    I prefer the H over the N brace. The N is harder to build correctly. People tend to cut the N braces notches too deep. The N brace tension wire then serves to break the 2nd post in the brace just above the ground. Additionally, securing N Brace the diagonal brace posts is harder than the H Brace. If the N brace moves, the diagonal will jack the end post out of the ground.

    • Michelle Canfield says:

      Rob, I agree, I think this is one reason why the H brace is the most popular, it’s just more straightforward to construct.

  20. Bryan Phillips-Petersen says:

    Hi Michelle,
    Thanks for your informative page, it has certainly made my fencing alot easier. Here is a question for you. What do you do when applying the H brace where the corner and brace post are not level, as the fenceline runs up or down a hill? To get the crossmember level on some of these H braces I need to build, will mean it reaches the corner and brace posts at different heights. What are your thoughts here on what is more critical – getting the crossmember level, or making sure it attaches to the corner and brace posts at the same height?
    Thanks Bryan

  21. Michelle Canfield says:

    Bryan, that is an interesting question, I had to think about it for a while. I think, when you think about the forces of the fence pulling on the brace, the pull is going to be parallel with the ground. So, conceivably, you could make the cross-member also parallel with the ground, though that makes for some tricky angle cuts which may not be convenient to do in a field. I think it would also be OK to make the cross-member level (to the world), knowing that it’ll be set low on whichever post is downhill from the other.

    When you think about a brace- say the case where the corner is on the top of a hill-the fence is going to be pulling it at an angle, which can be split into a horizontal force, and a downward force. So the horizontal pull is less than if the fence is not on a hill, and the H brace isn’t under as much strain, nor is the corner post as tempted to “flip” since the fencing is also pulling it downward. So it’s probably ok if the horizontal piece is lower on the corner post, as it doesn’t need to transfer as much load from the top as a straight fence does.

    In the case where the corner as at the bottom of a hill, the fence will pull at an angle which can be split into a horizontal force, and an upward force. Here I think it’s also ok to have the horizontal hit a lower portion of the 2nd post of the brace, because there is less horizontal pull, and not that much load on the 2nd post. The interesting thing about this scenario is that the corner post has two forces pulling it upward: the fence itself, and also the diagonal wire coming from the 2nd post. So, depending on how steep the hillside is, it may be worth doing something extra to discourage the corner post from popping out of the ground- like a good concrete footing, or a flared post that’s wider at the bottom.

  22. Karsten says:

    Thank you for sharing your thoughts on fencing. I live in Norway an am about to install an electric high tensile fence. The ground is rolling and rocky thus making bracing difficult. I wonder if you have any experince with or toughts on anchoring. Generally I do not see much information on anchoring the posts. Products like gripple ground anchor look easy to use and I think it sounds smart to string a wire from the top of a corner post to a ground anchor.

    Karsten

    • Michelle Canfield says:

      Karsten I don’t know much about those, but I recall reading about this scenario, so I think others have found solutions to this. IKencove fencing supply in the US has a lot of articles and solutions. I couldn’t find one on their various “earth anchor” products, but maybe you could email them and ask, or do a little more searching on that topic. I think in a way, once you get something successfully driven into the soil, the rockiness is a help, as it really deters movement, compared to soft soils. So the effort may be greater to install, but I bet it lasts a long time!

  23. james Bratcher says:

    Has any one ever heard of a flat rock support that a old feller told me years ago that they used a lot in the south west or sandy places, lets say its a 8 foor end post and you notch it say about 6 inches below the top , and then take lets say another 8 foot by say 4 inch and fix it so that it fits into the notch you made on the end post, and put a flat rock on the ground so that the other end of the 4 inch post lays on the flat rock, then you takle some high tensil wire or # 9 wire and wrap it around both post about 6 inches off the ground, and then after you tie the wires together , you twist them until they are tight, and as the fence sages, if it does you can twist the wire and by doing this, the post on the flat rock will slide on the rock as you twist the wires and push against the top of the end post, hope this is clear enough? Have a good day all, I just thought this was very impressive when the old feller told me about this.

    • Michelle Canfield says:

      James, yes, I have seen this type of brace described somewhere too. I searched for a diagram of one, and found one here:
      http://www.farmshow.com/a_article.php?aid=4494

      I’m trying to think if there are any downsides to it, it seems like it uses the same principles of physics and should work just as well. The drawbacks might be that the diagonal post needs to be long, so more expensive. And I think you’d have to make sure that the diagonal was in line with the pull of the fence. If it slips off to the side, it may fail. So I wonder if it would be worth adding something to make a “channel” so that the rock “slider” is constrained to only slide in the direction of the fence? Other than that, it seems like if you make them correctly, they should work. I wonder why this design hasn’t caught on more? Maybe just convention, everyone just does what seems to work for their neighbor…

  24. Fred LaChance says:

    Thank you for explaining WHY the diagonal wire goes bottom to to top, and which way is correct. I have searched and searched. Yours is the only good explanation I have ever found. I am hangin 12 gates, and now know HOW to properly accomplish the bracing. Again, well done and thanks.
    Fred from Oregon

  25. Edward Thatcher says:

    I have been in a debate about how to use a H brace. Does the wire attache to the H brace on both posts and is stretched in opposite directions in a manner that the wire is pulling against the other one?

    • Michelle Canfield says:

      Hi Edward, I’m not sure I understand what you are describing. The way I’ve done it, the wire is made into one continuous loop, that loops around both posts. Staple to the outside/top of one post, and the outside/bottom of the other post, to keep it from sliding vertically. Then it is tightened, so that it’s under tension. Either with a “twitch” type stick in the middle that you can twist; or with a ratchet-style tensioner. This way, as the end post wants to try to “flip” out of the ground, yielding to the tension of the long fenceline, the bottom of that post is pulling against the H-brace wire, which is pulling at the top of the 2nd post in. But the top of that post is pushing back through the horizontal beam, balancing out the tensions and encouraging that end post to stay in place.

      I’ve seen some people not use a loop, but rather staple a single strand to the outside of the posts. I don’t think this is as good, as it’ll probably encourage the posts to twist and get misaligned over time. It’s best to keep the lines of tension as straight in line with the whole fenceline as possible.

  26. Dan says:

    Is it possible to build an H brace that’s shorter and not as wide as the prior section? I’m building a short grape trellis (~15ft x 2 sections) and I’d like the end braces to not take up so much space. The tension on the trellis could still be significant. I see pictures all over the internet of trellises built without any real end bracing (or a single brace wire) and I feel that this just wont hold up in the long run, especially with vertical weight on the wire. Could I have a 5 ft high trellis, with a 2ft high h-brace on each end?
    I think I might still have to run the h-brace wire from the top of the last post, around both sides of the horizontal post (to eliminate any outward force) and to the bottom of the bracing post, so that the lever is still as complete is possible.
    Is there any way to build a structurally solid end brace that doesn’t take up as much space on either end of the trellis?

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