Building a gravel road

We recently purchased land to farm organically and are in the process of trying to get a gravel road put in. The county is requiring us to put in the gravel road before we can get any building permits, so unfortunately the type of rural road Paul recently discussed in his podcast won't work for us. The road is about 800 ft long and will be 14 -18 ft wide (depending on how successful we are in convincing with the county that 14 ft is plenty wide for firetrucks because we will have turnouts) and will be going over pasture. Of course our contractor wants to use Roundup to kill the pasture that will be under the road, then laying road fabric down and then the rock. Please be assured we will NOT be using Roundup!

My research into alternatives to Roundup so far is vinegar, torching it, and/or tilling it under. I realize tilling is not a permie thing, but if it is going to be under the road I am thinking it would be ok. Would you torch it and then till it under? How about torch it and then spray it down with vinegar? If you just sprayed it down with vinegar, how much would you need and how long would you need to wait before covering it up? Any other advice/ideas?

Thanks!

if you were to burn it, then cover that area with something before the gravel went down, wouldnt that eliminate the weeds growing up? (no sunlight, no growing)

I would lean towards burning it as it leave the roots to rot, and it isnt as permanent as some of the other options.

also, if you were to till it in, the ground may need to be [re]compacted so it doesnt settle.

Glad you pointed out that burning it would leave the roots to rot - that sounds like our best approach. and I didn't think about having to compact the soil if we were to till it in. Good thing as we don't have a tractor or rototiller yet and would have to either rent one or hire it out. Thanks!

You can lay down landscaping fabric, cover with gravel, stone, etc and then with finer grit to pack. Use it and that will keep down the weeds. Grade it once a year or so if needed. Frankly, I wouldn't worry about some plant growth.

I would strongly suggest you go with 18' wide rather than 14' wide. 800' is not terribly long for doing the work but a long ways to back out a vehicle even with some turn outs. Build well now. Realize you're going to lose some of that width over time.

We have miles of roads. We build our main roads by laying down waste stone from the local stone quarries and carving sheds. On top of that we put 4" stone. Then 2.5". Then 1.5" with fines. Then sand. This builds a very good road. Some years I then add more 1.5"- to the top as needed. For our logging and field work roads we don't get as fancy.

Crown, bank, ditch, culvert and all that good stuff.

Cheers,

-Walter Jeffries
Sugar Mountain Farm
Pastured Pigs, Sheep & Kids
in the mountains of Vermont
Read about our on-farm butcher shop project:
http://SugarMtnFarm.com/butchershop

Thanks Walter! We will be using road fabric - I think it's a little heavier duty than landscape fabric, but maybe it's the same thing. The county is dictating the size of rock (1 1/4" crushed and compacted and topped with 5/8")as well as the depth, forcing us to bring in a professional engineer to argue that using 3" rock for the base course and topping with 5/8" will work better. We have some pretty soggy conditions for most of the year on a portion of the road and think the larger rock will work better.

and of course there will be a crown - after listening to paul's podcast on roads, I couldn't possibly forget that!!!

The reasons for using layers of rock of different size is to build a firm base. Small rock such as the 1 1/4" will press downward too much in the base. Thus the larger stone deeper down. I very, very strongly suspect that the county is dictating the size of the top layer, not what you choose to do for a lower road bed. Building a strong road bed now means you'll spend less time and money adding material later. The bigger stones also allow water to drain out which is good.

Have fun.

laurie branson wrote:We recently purchased land to farm organically and are in the process of trying to get a gravel road put in. The county is requiring us to put in the gravel road before we can get any building permits, so unfortunately the type of rural road Paul recently discussed in his podcast won't work for us. The road is about 800 ft long and will be 14 -18 ft wide (depending on how successful we are in convincing with the county that 14 ft is plenty wide for firetrucks because we will have turnouts) and will be going over pasture. Of course our contractor wants to use Roundup to kill the pasture that will be under the road, then laying road fabric down and then the rock. Please be assured we will NOT be using Roundup!

My research into alternatives to Roundup so far is vinegar, torching it, and/or tilling it under. I realize tilling is not a permie thing, but if it is going to be under the road I am thinking it would be ok. Would you torch it and then till it under? How about torch it and then spray it down with vinegar? If you just sprayed it down with vinegar, how much would you need and how long would you need to wait before covering it up? Any other advice/ideas?

Thanks!

I've been an operator for over 30 years. Currently I do mostly surveying and I work with a civil engineer.

I've found that using the largest dozer you can find and carefully cutting and piling any plant matter, then the layer of roots, and overex any wet zones, then mixing and compacting along your route will make the best and cheapest dirt road. I've found crowning to be a bit troublesome to install and maintain compared to a simple cross slope with swales or water bars, particuarly on roads less than 25' wide. When water bars are longer, driving over them is not really noticeable and they take little maintenance. County roads and logging roads tend to need crowning because of the width and log trucks do not want to go over the water bars. With a crown, one half the horizontal from the center so vertical fall easily built in creates a steeper cross drainage each direction with crowned roads.
Also with a crown you have to get the water across the road, meaning a culvert which is a fair expense on top of the rock. Over the years, depending on the slope and road grade, they can be a pain.

If possible pick a few areas near the roadway to be planted to spread that root bearing soil over the grasses where it will all breakdown and leave a very rich planting area.

What I've found works best is a positively drained road, but also in steep ground what is safest and works very well is a negatively drained road with a water bar that takes about a 35' long stretch and makes it positive. I get these working on dirt roads. Of course if they are driven on wet they turn into a puddle but still work if you compacted the bars well. In your case, leave grades low about 4 to 6" for the gravel and make sure the water bars have nearly 8" for about 15' where the flow crosses it. Mix some dirt into the rock to bind it together and stretch your rock. Compact it too. Each one of those outlets can be the beginning of a keyline trench that causes maimum saturation.

I do exactly as you say, 3" rock on the bottom with 1.5 and smaller on top.

I'm not sure how you will think about this, but instead of landscape fabric that I would have to purchase, I did an experiment using carpet. I have a friend with a carpet store and the old carpet he rips out goes to the landfill. So I diverted some to use as road stabilizer under sugar sand. Some carpet is made of plastic so I don't especially like adding a non biodegradable to the soil, but I had to do something to firm up the road.

The sugar sand is almost fluid when driving heavy vehicles across it, it sort of splashes to the sides of the drive. The loose sand slows and sometimes stops 2WD vehicles. It even stopped my truck in 4WD when I was pulling a 20K lb trailer.

I used my tractor to scrape off 6 inches of sand, laid the carpet down, and covered it with sand. It has been down a year and I just had the farm logged. About 120 loads of logs, with truck and loaded trailer weighing well more than 60K pounds crossed the road section with carpet. The carpeted area held up well better than the uncarpeted zones, doesn't slow or stop vehicles, and my only complaint is that in some places the edges of the carpet got pulled up.

I think the 6 inches of sand should have been about 10 or 12 inches instead, but I'm afraid that much sand will not keep the road hardness I"m looking for. I might have to crack open the wallet and get some gravel to put on the carpet before the sand goes on.

I'm also planning on digging a small pond and am going to use several layers of old carpet under the pond liner.

This thread has a spot on subject line so I'll add some a source I happened on for dirt roads. I don't know who/what the organization is but they seem to have compiled several county publications from Montana and Utah on road maintenance. There is a lot of overlap and repetition between the publications so I'll just list one that seems to cover most of the ground. Others can be found simply by visiting the main domain at

http://www.gravelroadsacademy.com.

Here's the road maintenance pub. It is aimed at county road crews and references mostly power grader methods - but has lots of general info and road theory.

http://www.gravelroadsacademy.com/media/filer_private/2012/02/14/back_to_the_basics_gravel_road_manual_ii_1.pdf

And from another site, on the subject of crowns. This fellow sells front mounted rakes, but he provides nice clear explanations as well.

http://www.ruralhometech.com/RoadDrivewayMaintenance/RoadMaintenanceArticles/GettingyourCrowninShape/tabid/100/Default.aspx

And from the above site this short article on mud, quick road repairs and geocloth.

http://www.ruralhometech.com/RoadDrivewayMaintenance/RoadMaintenanceArticles/ABucketofStone/tabid/96/Default.aspx

And again, an overview of gravel road construction with specific comments on material and how to evaluate it:

http://www.ruralhometech.com/RoadDrivewayMaintenance/ADitchInTime/tabid/79/Default.aspx


Rufus

This appears to be the original gravel road manual used as a source for some of the above publications.

www.maine.gov/dep/land/watershed/camp/road/gravel_road_manual.pdf

A very erudite compendium of road design/build info from Cornell. In plain english and completely understandable but could easily be in the "more than you ever want to know" category.

www.clrp.cornell.edu/workshops/pdf/basics_of_a_good_road-2010-web.pdf

And courtesy of the Army Corp and the state of Mass, this one has very clear explicit illustrations and details of water and erosion control:

www.mass.gov/dep/water/resources/dirtroad.pdf


There is a great deal of overlap in the these publications. In my reading at this point I have stopped seeing much "new" material so I suspect the above resources may pretty much cover current wisdom on traditional roads. More can be found regarding water crossings, geotextiles and pretty surely there's more ideas and info on permeable road surfaces. But there doesn't seem to be a whole lot of shortcuts (read cheaper for just as good) available in road building, aside from doing good design and layout before the road goes in. Building appropriately for traffic and usage seems to be the biggest consideration. The geotextiles placed under the aggregate seem to be money savers after 5 years; one publication said the they also save money under roads or paths used by many heavy animals on a daily basis. Be interesting to see what accumulated wisdom is available for foot paths and trails.

Rufus

Thanks for sharing this info Rufus!

The basic principles to bear in mind are free draining load bearing material (your “clean aggregates”, the type & condition of the soils which will have to handle the loads & their relationship to moisture (i.e. water). Any “soils” which have excess moisture (“over optimum”) are considered “unsuitable” & should either be removed or aerated to remove excess water. Typically you would initially “clear & grub” the roadway area: remove any topsoil and organic material. If the material underneath is of a sandy-silty-gravelly combination of some kind you may be able to place your aggregate on top of that. Grab a clump of the material, make a hand cast, if it stays together with out crumbling & has no excess moisture on your palm it probably has close to the proper water content. Any mucky, pumping material should be removed down to “firm & unyielding material”. If you do not want to remove any material then you must “bridge” it , typically with something like quarry rock and a geotextile fabric. Just remember you are trying to build a load supporting structure which allows the water to drain. If you hire an engineer she/he is going to first and foremost look at your soil conditions, drainage topography and road loading requirements.

I started reading deeper into roads because my inlaws have a small patch that needs about 200 yds of "drive way" to access the back of their property. They're mostly city folk (northwest of Chicago) and walking back through knee high veg in rain or cold isn't going to work for them. This is minimal use, 3-5 cars/day tops on a single lane, on very fertile loamy soil; I don't know where the water table is yet, but it's all pasture or brush with no standing water.

Since it's very light use and no dreadful water issues they may start with a brute simple approach and spread and roll 3 inches of large gravel with an inch or so topping - very low-end; they'll have to herd it back into line every year but it will tell them how much more work is needed and how quick. After locating the water table and finding out what's under the top soil the plan may get changed some. But there is no onsite or nearby road building material that I know of - it's all former farm land, ostensibly level, that nature's had its way with for the last 40 years or so. No matter what they do it'll involve bringing material on site.

I suspect the gravel may vanish downward in short order but I didn't discover any great harm in that. If it heads for China too fast then it looks like they should just put geo-cloth down and do a proper little road build; if it goes away slowly, then maybe just try a redo in three years and see if it lasts longer this time. Nothing really romantic or challenging but it was good learning about roads and it'll be fun trying to find some slope on their property. <g>

Rufus

Sounds like rich topsoil, which means little to no compaction over the years.Great for growing,bad for roadbase. With your approach try to compact the soil when it is in a semi dry state. If your folks can afford it put down some geogrid fabric then crushed aggregate, 3 to 4" in size if possible. Then your "top rock" if desired. If the pasture land easily drains water this may make a passable road for light cars and trucks. Without some seperation between rock and soil it's really iffy the road would make it through a wet winter.

Rufus Laggren wrote:I started reading deeper into roads because my inlaws have a small patch that needs about 200 yds of "drive way" to access the back of their property. They're mostly city folk (northwest of Chicago) and walking back through knee high veg in rain or cold isn't going to work for them. This is minimal use, 3-5 cars/day tops on a single lane, on very fertile loamy soil; I don't know where the water table is yet, but it's all pasture or brush with no standing water.

Since it's very light use and no dreadful water issues they may start with a brute simple approach and spread and roll 3 inches of large gravel with an inch or so topping - very low-end; they'll have to herd it back into line every year but it will tell them how much more work is needed and how quick. After locating the water table and finding out what's under the top soil the plan may get changed some. But there is no onsite or nearby road building material that I know of - it's all former farm land, ostensibly level, that nature's had its way with for the last 40 years or so. No matter what they do it'll involve bringing material on site.

I suspect the gravel may vanish downward in short order but I didn't discover any great harm in that. If it heads for China too fast then it looks like they should just put geo-cloth down and do a proper little road build; if it goes away slowly, then maybe just try a redo in three years and see if it lasts longer this time. Nothing really romantic or challenging but it was good learning about roads and it'll be fun trying to find some slope on their property. <g>

Rufus

Michael

Thanks for the comment. From what I've read, geo-textile under a 4" base rock with a topping should almost certainly work well unless the "sub soil" turns to mud in whole or part. Thinking about it, maybe they should just extend the existing parking lot 50' or so along the proposed drive with 3" of large gravel, rolled; if they drive back and forth on it a few times each day when they are using a vehicle by next spring they will have an idea of what's going to happen. A small test now might save a year or so of experimenting with the whole length. They won't get the drive in until next year anyway.

Rufus

Rufus Laggren wrote:Michael

Thanks for the comment. From what I've read, geo-textile under a 4" base rock with a topping should almost certainly work well unless the "sub soil" turns to mud in whole or part. Thinking about it, maybe they should just extend the existing parking lot 50' or so along the proposed drive with 3" of large gravel, rolled; if they drive back and forth on it a few times each day when they are using a vehicle by next spring they will have an idea of what's going to happen. A small test now might save a year or so of experimenting with the whole length. They won't get the drive in until next year anyway.

Rufus

A test section is a very good idea! Another thing which could be tried at little or no extra cost is called"proof rolling". When the first loaded dump truck arrives,prior to dumping have the driver slowly drive (a walking pace) aalong the 50 foot area. Look at the tracks, if some areas have a deeper deflection then the rest those areas will be the ones to really watch during the winter"test" driving

Michael

> proof rolling... dump truck

Thanks for that! Makes perfect sense and I _like_ getting as much out of (expensive) resources as possible. <g>


Rufus