crown on driveway

[stmiller2]

The Progressive Farmer web page has a snippet from an article that gives advice on roadway gravel size and depth.

 

[Kent]

Helpful road building links

I am sure I found all of these resources in this forum, but here they are together in one place:

USDA Manual
Army Field Manual
British Columbia guide
Backwoods Home article
Drainage Problems
Materials Calcuator

There are many product/implement-specific tip sheets as well, but they tend to favor one way of doing things, so I didn't include these. For example, installation sheets from conduit (e.g. Contech ) and geotextile vendors, or instruction sheets from implement mfgrs (e.g. Terrabond ). I remember a really informative tutorial from a heavy-duty truck-mounted landscape rake mfgr, but I can't seem to find it right now (I noticed last year a gravel road crew in NH using this implement with great success churning up 4" of gravel, but my 3-pt hitch rake is only heavy enough for a light smoothing).

 

[gerard]

I'm with soundguy - If you're putting down clean gravel I wouldn't worry about crowning for his stated reasons. Once you top with running crush that has some fines, then worry about crowning since then, even while still somewhat porous to water, in a medium to hard rain, the surface won't absorb the water as fast as it's coming down and you'll have surface runnoff. That's when you'll want the crown to prevent the water running lengthwise down the roadbed in the tire rutts. Kind of pricy for a 1000 foot road but if you REALLY want to do it right lay down some geotextile fabric FIRST, then put your base on that. It'll prevent your base from migrating down over time. (15 foot x 300' roll is about $150 if memory serves.)

 

[John_Mc]

</font><font color="blue" class="small">( That would be great on a hard surface road that is shedding water.. gravel is so porous that water will be traveling beneath the substraight... it will be like an aquifer... I'd go flat.. besides.. it'l crown on its own with traffic.. and he'll have to blade that out as well.)</font>

Actually, JMIII's formula (1/2" per foot) is standard operating procedure around here. In addition to reducing erosion from running water, it helps prevent standing water on the roadbed. Standing water is a road killer, since the puddle area softens up over time and turns into a pothole. That becomes a vicious circle, since the pothole now holds more water, which softens up a larger and deeper area. Maybe this doesn't happen in Florida, with the type of dirt/gravel you have down there, but it's a major concern up here.

John Mc

 

[gsganzer]

That's the scenario I've found on my driveway. The last time I graded, I crowned and sloped to prevent standing water. Like you said, a puddle leads to a self-perpetuating downward spiral.

 

[Soundguy]

I think you are missing the point I am making. I didn't argue against the 1/2" per foot.. etc.. I said that on a roadbed made of large gravels.. it wouldnt make a difference. If he has a surface course of gravel fines, silt, clay, or limerock that will hold/shed water.. then yes.. crown it by all means. If he has a 3-6" deep gravel like 57 stone... water is not going to puddle on top of it.. it will run thru it like a seive.

I'm familiar with potholes.. florida is virtually all carst topography due to our aquifer.. besides.. I've already had pothole 101 in college ( civil eng. )

Soundguy

 

[oldmisterbill]

This is an interesting topic - I have been dealing with Oklahomas torrential rain latley. (origionally from Pepperell Massachusetts) Which I am not used to.I did custom tractor work in MA. I never had a box blade but used a scraper blade & a york rake (stone rake is what it is called in this area) the thing that amazes me is there are very few rakes in this area and most seem to rely on a box blade only. In my opinion I would atke a rake over a box blade if I had a choice of only one tool. Why? because after it is roughed out with a box blade a rake will finish it almost perfectly, When it needs repair or refinishing,a rake will move only enough material to level and fill the holes or ruts. This in my opinion leaves the hard packed material untouched still packed and only the small amount moved needs to repack. I did a lot of this in MA ,and felt I was doing people a favor. Then when I moved down here 13 years ago I was surprised to see box blades every where. I used one for the first time last year -it was great,but I spread two truckloads over a washed out drive and still liked the rake better for a better surface and grade. I used the box for some narrow excaviting & spreading next to a foundation and loved it.

I think this is a good subject for disucssion and to be critizied as a means of improving our skills.