My next project: 1000ft straight fence... But how do I make it straight?

Hey everybody!

So I have to build a fence which is 1000ft in length, straight, and a decent amount of variation between the two ends. The main question I have is: How do I use the Bosch GRL 240 laser level to make a straight fence line? I have searched and searched online and have yet to find a straight forward tutorial on how to use this pricey piece of equipment I have recently purchased. The string method did not seem viable due to the amount of distance, and the continual wind coming from the south, so I broke down and bought this level. I am scheduled to start flagging the fence line this Sunday, and could really use some help on how to make use of this level to help make it straight!

Thanks for your help in advance

Sincerely
Berns Fernand

You can do it a few simple ways such as sighting down three poles to locate the next, my favorite is I cut two really long poles and put them at the two ends and run a string high enough to be overhead for the rest of the work, 1000 ft might be two or three rolls of Mason's twine, but hey!

The old farmer method is to set the end/corner posts and then run a wire tight. Improved method is to use a transit to place poles on the hilltops to keep it straight over the hill.

Variation between two ends...

Can you see one end from the other end? In other words you have undulation, but both end points have line of sight? Or is on not visible from the other? If both are visible, then it is much easier. Mark a post at both ends. Starting at one end move a flag out 100 feet from the point of origin. Walk back to the end post and ensure, visually, that the flag is inline with the two end points. Set laser behind first flag and shoot the same angle at a flag 100 feet further. Ensure visually alignment with the end points and flags. Repeat 7 more times. Now you have a 2 end posts with 9 flags spaced 100 feet apart.

If you can not see both ends from one another, this will be a longer process. Instead of lining up the two end points, take a compass bearing. Then follow the same process to make a straight line out 100 feet along that compass bearing. Repeat until the second end point comes into sight. If the tangent angle of your fence is off the mark (but a straight line), then adjust the flags to match the angle of error. Repeat the process to confirm. Continue refining the error (angle of declination), until you are satified the fence is straight and runs post to post.

Having never used a laser level, I can not give you exact instructions, but do have something to add. The legs of your tripod has 3 points. Using a compus shoot an azimuth (compass bearing) from each leg through the other 2 legs. Much easier if you set up two leg in a line that follows magnetic north (or east, west, south.) Make sure everytime you move the laser level, the feet align to these same 6 angles. That will give you continuity. Now make sure your laser head does not move from the angle in relationship to the legs (should have a 360 degree dial for reference under the laser). This way the line created by the laser will consistently align with the legs. The legs will be the same each time. This is triangulation. But instead of triangulating on a fixed point to determine exact location, you will triangulate the 3 consistent angles between the legs as your position changes. The more accurate your compass, the straighter your line will be.

Don't be afraid to do this as many times as it takes, making small adjustments, until you are perfectly happy with the fence plot. Once you are comfortable with the 100' flags, shoot a line between each flag and mark your post locations. Take your time. You will have to look at that fence for a long time.

Just for fun, here is a little ditty to add some humor to your task:

Thanks so much for the quick replies!

As far as seeing from one end to the other, no, there is to much grade variation to see straight across. That's the part that I am clueless about getting around! Maybe use my rifle scope and I might be able to sight it that way... Im just not sure how I would point the laser level on that exact marker in order to get the straight line where I need it. Again I have never used a transit level before and the videos Ive seen certainly do not answer my questions! (Which is why Ive come here)

As far as using the compass to find true north, is there simple video you would direct me to where I could learn to do that? I have never used a compass before (grew up in the city with google maps on my phone) so I don't know the first thing about using a compass.

I bought the laser level so I could avoid the toil that comes with the string and wire method (even though I used the string method on the 500ft fence) given the length of the fence I need to construct. With the model of laser level I bought, and being that it is a rotational, could I still use it to set a straight line?

Thanks for the correspondence!

Berns Fernand wrote:... and being that it is a rotational, could I still use it to set a straight line?

You could; but it is making it more complicated than it needs to be. I looked at some videos of the particular level you have. Being rotational, its strength is not a setting a straight line to a fixed distant point; although you could use it for that, I suppose. Your simplest solution is to do find the direction of travel of the property line on a map. Using that angle between the property line and magnetic north, use a compass to duplicate that angle from an end post. Then use the compass to sight along that angle as far as line of sight allows. For that you could use a standard laser pointer of fixed laser. Then move to the last point and take a line of sight along that angle, repeating until you hit your far end post.

As far as how to use a compass for this. Here is a very simple 60 instruction. There are more complicated videos, but it does not need to be any harder than this. The big trick will be to find the angle of the property line to magnetic north. Do you have a platt map or survey of the property? Does you County have GIS data on their website? Can you post a link to a google map image, so we can help?


Start at 50 seconds into the video.

Berns,
Without seeing the place it is hard to imagine what you are dealing with. Do you have a picture of the fence line?

So if you used a rifle scope you would be able to see the other end of the 1000 ft fence line?

Do you have a post at the other end that you could see through the scope?

Are there lots of trees in the line of site ?

Do you have someone else who can help with the project or are you alone ?

I was thinking that you could put some sort of strong light/lantern on top of the far post and set up the laser at your end. After the sun goes down you might be able to see the light and aim the lazer at it to get a pretty close line? Then mark a few points between.

If you have two people one can stand behind the laser, looking down the line at the light, and the other could walk down the line . You could have them go right or left to stay in the line and pound a couple of markers along the line.

Then next day you would be able to finish the line?

I'd go with Chads method . Is was good enough for the romans over two thousand years ago and man did they build straight roads

Wow! Great advice guys! I attached the survey of the plot.

- The line of sight was covered by trees but I have removed them and cleared the line. With my scope I should be able to sight it fine.

- The compass video was great! I will go buy one and use the line method when placing my tripod legs and positioning the level.

- I will have a buddy helping me out and could use him. However I am still unclear about how to make the laser level I bought point in one direction. I guess it will be a trail and error type of deal.

If there is any more videos on using and understanding the compass that you would recommend, I would certainly appreciate it. (Literally never used a compass as sad as that is)

I will take some pictures for you guys when I go out there on Sunday so you can see my travail.

Thanks for the guidance!

Berns Fernand

Could you use your phone(with gps) to set temporary intermediate posts that are close and use the compass and laser to refine the positions?

Rotary laser levels like the one you have are typically used to determine grade, not set straight lines. However, if it functions on it's side, and could somehow be mounted sideways, and it's "self-leveling" feature didn't get in the way, it might be made to work. The product description does say "horizontal and vertical," but I'm not sure what they mean by vertical (unless it works on it's side). Edit: Or maybe there's a way to stop it from rotating?

Okay. The map is perfect. It has all you need on it.

From the chart in the left margin you know the fence line, L49, runs from South to East at an angle of 59 degrees on your compass dial. Depending on how precise your instrument is, it further breaks the degrees down to minutes and seconds (fractions of a degree.) 31 minutes 44 seconds. Your compass will not be that accurate, but perhaps a gps would be? Survey's equipment is obviously very precise.

So standing by the country road 479, look North towards the gravel drive and the other end of the fence line. (the two ponds should be on your left.) Looking down at the flat compass in front of you, point the d.o.g. or direction of go from the video, at the far end of your line. Rotate the dial until the floating needle is inside the red 'dog house' on the base plate. The dial or bezel on the compass should read 59 degrees (+/- 2 degrees.) The compass will get you close, but even a small rate of error over 1000 feet will put you off your line. I would place flags along a line you establish with the compass.

Using your scope (safety first - open the bolt/breach/chamber) sight in the far post. Have your friend move the first flag left/right until the flag is inline with the scope and the far post as you look through the view finder. Simple hand signals will tell him which way you want him to move. Move to the next flag and repeat. Quickly the ragged line of flags will come into a very narrow line in the scope as he works further out.

Clearing those trees so you have line of sight will be worth the extra work. You will be able to get an accurate fence line with line of sight and magnification.

My curiosity got the better of me and I had to look it up because I work with a level similar to yours quite frequently.

It does work on it's side! (Or I guess technically, it's back.) That's how you get vertical functions, which should also work for shooting a straight line. Perhaps even better, it has a "line" function and a "point" function, so you should be golden. There are more details in the manual, which is available at homedepot.com among other places.

What type of fence are you building? Wood? Wire?

The guy who said to set the corners then stretch a tight wire between them was right. When I would do it, I'd stretch the wire with a tractor if need be to tension it enough, but was using a heavy gauge barbed wire or Number 9 smooth wire. Lift it and drop the taught wire a few times and it will work itself dead straight. A tight wire isn't going to bubble, sag or move around on you like string would. Tension it up straight and set your line posts touching it. If you can't connect the wire the entire way, and you have 1,000 feet between your corners, a set of brace posts halfway is only 500 feet apart. Tension your wire to those. Before you go farther than setting your line posts, go back and sight down them. If any one of them is the least bit out of line, move it. Shouldn't be if you set each post next to your tight wire. Also sight down them to make sure the top of each line post is set to the same depth. The only thing worse than a fence that isn't dead straight is one that jogs up and down. Ground varies, but the tops of the posts should not, except to make a very gentle sweep to follow the contour. There is a vinyl fence I drive by every day and they didn't do this. They set each post exactly the same depth, such that the top of the fence bounces up and down and it looks hideous.

Also, before you build this fence, you may want to inform your neighbor and get him involved to help you lay it out. You don't want him coming around after the fact telling you it is in the wrong place. Fence laws vary, but in some places, tradition has it that two neighbors are to share the cost of building a fence and in maintaining it. As you stand on your property and view the fence, your half is on the right. But don't take that as gospel......traditions vary. And don't assume he will pay for half the cost, even though he benefits from it as much as you do. Some neighbors are like that.

Edited to include this: Building a property line fence is not something you rush into. Location matters. Imagine if the fence bubbles onto your property 5 or 10 feet, or on to his. If on his you are claiming and using his property as your own. If on you, you are doing the same for him. In most jurisdictions, there are not well understood laws regarding claims of ownership over boundary disputes and putting fences in the wrong place is often the cause of the dispute. Take the time to get it right!

David Spohn wrote:My curiosity got the better of me and I had to look it up because I work with a level similar to yours quite frequently.

It does work on it's side! (Or I guess technically, it's back.) That's how you get vertical functions, which should also work for shooting a straight line. Perhaps even better, it has a "line" function and a "point" function, so you should be golden. There are more details in the manual, which is available at homedepot.com among other places.

Hey David! Its my first time working with a laser level like this and it is a bit intimidating to say the least. I think the laser is over kill for this job after considering all the great advice I got on the matter. I may send it back that is unless you could fill me in on some other permaculture projects it may come in handy for (also building projects such as a mid sized home in the future)

I read the manual and the rotating head can be made to sit still, but when in the point mode the receiver does not work and therefor you are left with out an accuracy indicator. So that was a big disappointment to me as I was messing with it last night. I look forward to possible justifications of keeping it so fill me on because as I said, Ive never used, nor known anyone who knew how to use this piece of equipment.

Thanks!

Eugene Howard wrote:What type of fence are you building? Wood? Wire?

The guy who said to set the corners then stretch a tight wire between them was right. When I would do it, I'd stretch the wire with a tractor if need be to tension it enough, but was using a heavy gauge barbed wire or Number 9 smooth wire. Lift it and drop the taught wire a few times and it will work itself dead straight. A tight wire isn't going to bubble, sag or move around on you like string would. Tension it up straight and set your line posts touching it. If you can't connect the wire the entire way, and you have 1,000 feet between your corners, a set of brace posts halfway is only 500 feet apart. Tension your wire to those. Before you go farther than setting your line posts, go back and sight down them. If any one of them is the least bit out of line, move it. Shouldn't be if you set each post next to your tight wire. Also sight down them to make sure the top of each line post is set to the same depth. The only thing worse than a fence that isn't dead straight is one that jogs up and down. Ground varies, but the tops of the posts should not, except to make a very gentle sweep to follow the contour. There is a vinyl fence I drive by every day and they didn't do this. They set each post exactly the same depth, such that the top of the fence bounces up and down and it looks hideous.

Also, before you build this fence, you may want to inform your neighbor and get him involved to help you lay it out. You don't want him coming around after the fact telling you it is in the wrong place. Fence laws vary, but in some places, tradition has it that two neighbors are to share the cost of building a fence and in maintaining it. As you stand on your property and view the fence, your half is on the right. But don't take that as gospel......traditions vary. And don't assume he will pay for half the cost, even though he benefits from it as much as you do. Some neighbors are like that.

Edited to include this: Building a property line fence is not something you rush into. Location matters. Imagine if the fence bubbles onto your property 5 or 10 feet, or on to his. If on his you are claiming and using his property as your own. If on you, you are doing the same for him. In most jurisdictions, there are not well understood laws regarding claims of ownership over boundary disputes and putting fences in the wrong place is often the cause of the dispute. Take the time to get it right!

Hey Eugene,

Thanks for the advice! My neighbor and I are working together on this fence and sharing the cost as well. As far as the using the string of wire, I thought about it, but the distance kind of turned me off to this method. Plus I spent 400 bucks on a laser so I am hoping I can use that for this project... if not I will be sending it back. I will do my best to make the 47" woven horse fence as ascetically pleasing as possible while still keeping it effective in what it is supposed to do. Ill keep you guys posted with some picks after my Sunday session out there to let you know what progress I made with what method.

Thanks again for chiming in!

Jack Edmondson wrote:Okay. The map is perfect. It has all you need on it.

From the chart in the left margin you know the fence line, L49, runs from South to East at an angle of 59 degrees on your compass dial. Depending on how precise your instrument is, it further breaks the degrees down to minutes and seconds (fractions of a degree.) 31 minutes 44 seconds. Your compass will not be that accurate, but perhaps a gps would be? Survey's equipment is obviously very precise.

So standing by the country road 479, look North towards the gravel drive and the other end of the fence line. (the two ponds should be on your left.) Looking down at the flat compass in front of you, point the d.o.g. or direction of go from the video, at the far end of your line. Rotate the dial until the floating needle is inside the red 'dog house' on the base plate. The dial or bezel on the compass should read 59 degrees (+/- 2 degrees.) The compass will get you close, but even a small rate of error over 1000 feet will put you off your line. I would place flags along a line you establish with the compass.

Brilliant Mr Edmondson! I am still little unclear on the degree bit. Are you saying if I keep with the same degree and direction of travel, that I should be able to establish a straight line walking in the DOG and flagging off every so often? I also forgot to tell you, technically the L50 line is my side of the property, but Im not sure that makes it any different...

In short I think I understand the concept your conveying but am not fully confident as of yet that I understand the application of the concept for the purpose of making the straight line. (Forgive me for the ignorance that was passed down to me by my unknowing parents!)

Im sure you can clarify, and appreciate the info you have given thus far! (very practical)

when in the point mode the receiver does not work

Ah, that's a bummer. Good to know though. How about using it on it's back, just sitting on something flat rather than the tripod? Can the receiver mount be adjusted so it sits horizontally on the rod? I can't play with ours right now because it's in my partner's garage.

We use ours almost exclusively for shooting grade in landscape projects (paver installations, retaining walls, etc.) and they really are great tools for that, even though there is always an "analogue" way to get it done. It replaced an older-style transit, which was a 2 person job. I can imagine a few other things it would come it handy for, like building a foundation or a floor, but in general I'd say it's more about efficiency than necessity. Were I building a mid-size home (maybe someday) I'd keep it around, but I guess I'm a bit of a tool hound. Hope that helps.

Berns Fernand wrote: I look forward to possible justifications of keeping it so fill me on because as I said, Ive never used, nor known anyone who knew how to use this piece of equipment.

If you were looking to put in swales in the future; or do any keyline plowing, it would be helpful for that. Here is a brief explanation of how that is done with a laser level.

Berns Fernand wrote: Are you saying if I keep with the same degree and direction of travel, that I should be able to establish a straight line walking in the DOG and flagging off every so often?

Yes, exactly. Find the angle of 59 degrees on the dial of the compass. With the D.O.G. arrow pointing straight ahead (pointed at the far end post of the fence), walk a straight line towards the post. Place a flag at whatever spacing your fence posts will be at. Technically, you don't even need the compass, since you have line of sight. You could have someone walk the L50 line and place a flag, as you stood behind the corner post and lined him up visually. But just walking along the 59 degree compass bearing is easier.

Berns Fernand wrote: I also forgot to tell you, technically the L50 line is my side of the property, but Im not sure that makes it any different...

L49 and L50 are identical. But if you start at the other end of the fence line, use the reading of 239 degrees and walk south. (180 + 59 degress = 239.)

Hi There, I'm in the UK. I love the permies site. I worked as a fencer for many years and my fences are straighter than a laser.
YOU CANNOT use a laser to build a fence (daylight) What kind of fence do you want to build and would you like the TOP of the fence to also rifle in asa well as the line?

Ben bluebird ben@tractionsound.com

Hello everyone, I just wanted to touch base with you guys and share some updated photos of the first part on the fence project that has been completed. I used all three methods that were proposed in the above Forum posts Including the laser level, the string method, and the compass method. The laser level got me very close While using the compass to guide the aiming of the straight laser line. The string was used as A quality control check since I was a first time laser level user for that kind of project. I got my neighbor out there once I determined the path for the T posts and H braces and we both agreed upon the placement. I'll be going back out again in a few days to complete a section or two and will be sure to update you with more pictures as a project comes along further. Thanks again for all the support you guys have provided on this awesome forum!

That's a fine looking fence - nice work!

Bravo Berns !

Great thread! Are there laser levels that come fitted with a compass to help point the vertical beam it in the right direction - or did you have to use a separate handheld compass?