Any Excavation Professionals Feel Like Giving Advice?

[The-AJ88]

I am in the process of talking to a few local excavation companies in regards to a project. It's a simple project (they all have said this), but each has their own method of completing the project. I've been wanting to get this project done for a while now, and life keeps on getting in the way so I will be hiring this one out to a professional.

The project is a 30' x 30' gravel parking pad. The area where it will be installed is currently grass and soil. The area slopes approximately 1.5' right to left over the 30' area and 1' front to back over the 30' area.

My question is: is there truly a "right" way to do this?

One guy said he would strip the soil down to clay, use #1 and #2 limestone as a base, then top dress with #57 limestone

One guy said he would strip the soil down to clay, use geo-textile fabric, use #1 and #2 as a base, then top dress with #57

One guy said he would NOT strip any soil, use asphalt chunks and grindings as a base, the top dress with #57 lime stone

They all claim that their way is the "best" way.

So, I am seeking an outsider's opinion which method seems the most logical to go about this project.

Thanks

 

[ddbackhoe]

level pad? Are they sloping the low sides or how is the 1.5 foot slope accounted for? Any of them happen to mention anything about compaction rates? Haul away of spoils or spread on-site?
Material price is area dependent. I can place millings for 100/load double grind for 200, #2 is almost 1000/load, #57 is almost 1200/load

Without seeing the site - I would remove grass/organics and level, compact, millings (compacted), top dress with double grind and compact

 

[crashz]

The second guy has the best option.

#1 an #2 stone is heavy course stone. I would expect the contractor to strip the sod and organics, proof roll, place the geotextile and place the heavy stone on top. No real need to roll/compact the 1s and 2s, but you could. When the #57 is placed on top, this should be well compacted not just for smoothing the surface but to interlock the smaller #57 stone and fines into the base layer. Once compacted and saturated (rain or a hose), the parking area will be solid.

We built a truck access road in Ohio last year with the same method through a low area adjacent to wetlands. Due to the pumping nature of the saturated clay subgrade, we placed a 18" thick layer of the 1s and 2s with 1ft of #57 with geotextile at the bottom and geogrid between the layers. The road handled flooding conditions and many thousands of truck loads without any maintenance. Not even a single rut or depression. Was so solid that the owners wanted to keep it for future access.

 

[LS Tractor Owner]

Agree, contractor #2 has the better method. The geotextile will prevent the rock from sinking.

 

[Snobdds]

You need to get the top layer of organic material off, otherwise it will turn into a mud pit when wet. That is basic and the 3rd guy has no idea.

The fabric will keep your rock above the clay.

#2 would get my money...

 

[Omega Woods]

Not an expert but even I know the third guy isn't the right person for the job.

I would go with #2 myself based on the info you've provided.

 

[CADplans]

When they cut my timber,,
the loggers built a road, 1/8 mile long.
They stripped the topsoil, and left a SLIGHT side to side grade.
Next the soil was covered with railroad ballast.
Then, after running in the RR ballast with a D6 CAT, the road was top-dressed with 57's

The ran 160 loaded 18-wheelers over the road during the wettest spring we have seen in over 40 years.
The trucks all had overload permits, they were not allowed on the interstate due to excess weight,
so, they must have been significantly over 80,000 pounds.
The road is still perfect, 7 years later.

 

[Rockbadchild]

Definitely strip the organic matter this will decompose and cause the area to settle unevenly overtime. Geo-textile fabric is a good investment to save on material in the long run.

As far as material goes there is different name depending on area and to make sure we are talking about the same thing;

What is #1 lime stone and what is #2 lime stone ?

The most cost effective would be to used type 2 sand (screen pit run) to fill the low spot first that's the cheapest material and it provide good drainage and compaction, then 4 inch of 3'' minus and thin layer (1'' or so) of A gravel (1'' minus) on top.

Grinded asphalt mix with gravel do add compaction to gravel... but I am not sure if I would want that on my property, they uses it on roads shoulders all the time, its a good recycling method and it as benefit... but I would personally pass

and of course everything need to be watered and compacted properly.

 

[crashz]

Ohio DOT sizing is:
#1 stone is 3.5 - 2.5"
#2 stone is 2.5 - 1.5" stone

 

[Rockbadchild]

I wouldn't want to used pure stone as a base, I want any material to go down to dust in order to provide compaction. Pure stone doesn't provide any compaction.

 

[paulsharvey]

I dont like #57 stone for a parking area. It never really firms up, and is an added expense. Only way #57 really firms up, is to be pushed into finer material.

Material vary a Lot area to area, but I would strip organics/top soil; add clean fill to about 6" below final grade; you choice/$$$ of asphalt millings, crushed roadbase, or crushed concrete (not gravel, from fines upto rocks, so that the diffent aggregate grades lock together). If it's an erosion prone area, prime with asphalt prime and spread granite screens. Boom, done for 15 years. Crushed concrete is and will always be dusty, but water doesn't bother it. Limerock road base gets a nice 'seal' on the top, but fines will get muddy, and/or erode. Millings aren't very dusty, resist water/erosion well, and does somewhat lock together. Don't belive the myth that the summer heat will melt it back into asphalt, that doesn't happen.

Parking Pad implies wheel turning, and a pure 57 stone will get loosened up by all that turn.

An cheap option would be 6" of sand-clay, topped with less finish material, maybe 3".

Edit: ball field clay, not a fat gumbo with a bit of sand...

Geofabric increases the time to see problems with the subgrade, but it doesn't actually prevent it. Better to address the root cause, unless it's bottomless muck.

 

[Rockbadchild]

It sound like these contractor only want to use different size of pure stone, this will result in a never ending grading mess, it will create tire tracks each time something heavy drive on it or even over time by driving in the same tracks it will push the stone away and spreading it away (It wont stay in place).

 

[paulsharvey]

With material pieces right now; compare your 3 quotes to what 6" of concrete would cost. Quick math says concrete would be 16.667 CY; at $135/yard; plus excavation cost, and pour/finish. If your getting quotes of, say, $4k for just dirt work and base, consider what your really getting.

I might even go 5" thick, as long as your soils are good; and I personally belive in WWF over fiber, but thats just me...

Regardless, you'll want to strip the top soil and organics.

 

[MapleLeafFarmer]

I see there is no mention of what the areas drainage is like.
Personally whenever I can I am fond of subsurface drainage systems (field tile/weeping tile) under gravel parking.
Should be cheap in your area and maybe something to consider?

 

[dodge man]

I agree #2 would be best. Depending on conditions #1 might be fine also, you don‘t always need fabric.

 

[Rockbadchild]

I agree #2 would be best. Depending on conditions #1 might be fine also, you don‘t always need fabric.

You would be fine with making the whole base with only pure stone ?

 

[ovrszd]

I've never heard of leveling a 1.5ft slope in 30ft with rock.

Remove sod. Add 2 dump truck loads of clay to level pad. Use removed top soil for off pad slope on low side. Add gravel to taste.

You need 42 cu yds of material to just level the pad. A dumper will hold somewhere around 20 cu yds of compacted clay. Why would you want to do that with gravel?

 

[Streetcar]

I dont like #57 stone for a parking area. It never really firms up, and is an added expense. Only way #57 really firms up, is to be pushed into finer material.

Material vary a Lot area to area, but I would strip organics/top soil; add clean fill to about 6" below final grade; you choice/$$$ of asphalt millings, crushed roadbase, or crushed concrete (not gravel, from fines upto rocks, so that the diffent aggregate grades lock together). If it's an erosion prone area, prime with asphalt prime and spread granite screens. Boom, done for 15 years. Crushed concrete is and will always be dusty, but water doesn't bother it. Limerock road base gets a nice 'seal' on the top, but fines will get muddy, and/or erode. Millings aren't very dusty, resist water/erosion well, and does somewhat lock together. Don't belive the myth that the summer heat will melt it back into asphalt, that doesn't happen.

Parking Pad implies wheel turning, and a pure 57 stone will get loosened up by all that turn.

An cheap option would be 6" of sand-clay, topped with less finish material, maybe 3".

Edit: ball field clay, not a fat gumbo with a bit of sand...

Geofabric increases the time to see problems with the subgrade, but it doesn't actually prevent it. Better to address the root cause, unless it's bottomless muck.

Ohio does not use granite screening, trucking is too expensive

 

[Streetcar]

57s are not good top coat for parking, 304 is better option.

 

[3Ts]

For those of us that don't work in the excavation or road building fields, what is #57s and what is 304? (The #1 and #2 stone is defined in post #9.) I've heard of "3/4 minus" being used for "road base" which I've found out there is a particular percentage of sizes from 3/4" down to "fines" and that there are 3 or 4 different screen sizes involved.