Estimate Question

kubotaman333

Could any one offer me an estimate on how much 6 inch rip rap I would need to do a rip rap ditch (6 feet wide, 20 inches deep V'd from the middle up and 450 feet long). Any help is appreciated thanks.

dayexco

you've got your dimensions already, rest should be simple math?

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someday, i'll be as patient as Nick.

cexcavation

70 cubic yards........If I were bidding, I would up it at least one load to 80 cubic yards. Am I the winner

tgeb

You might want to check your numbers C.

6 X 1.75 X 450 = 10.5

10.5 X 450 = 4,725

4,725 / 27 = 175

Only about 100 cubic yards off. And in reality it could be more depending on the actual profile of the 6' wide ditch.

Kubotaman, it is simple volume calculation, length X width X depth.

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Tom

www.gebcon.com

1mancrew

6' wide ditch - 20" deep
When drawn out - each side is 3.5' from top of ditch to bottem center
2 sides - 7' x .5' (6" rip rap) = 3.5'
3.5' x 450' long = 1575 cu. ft.
1575 cu. ft. = 1575/27 = 58.33 cu. yd.
Bid 70 and if it only takes 60 = take your guys out to lunch =
Of couse you can always ask the aggregate supplier and they will tell you how much you need.

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www.KirbyCustomHomes.com

tgeb

Ohh, Maybe I miss understand. It does not get 20" of rip rap?

When he said 20" deep, I took that as the depth of the stone.

Kubotaman.....can you clarify?


Somebody help me, I can't use the internet with out pictures.

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Tom

www.gebcon.com

rbsremodeling

I'd just sub it to that Tgeb guy his math skills seem better than yours. Seem like that would make life easier for you.

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tgeb

My math is good......it's my comprehension that is a little fuzzy.

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Tom

www.gebcon.com

cexcavation

I think my numbers are good....."lining" vs. "filling" as well as "V'd out"is where the discrepancy lies. Also, I always figure a 15% into my initial numbers to account for "irregularities", compaction, etc. That is where the initial "safe" number comes from. Then if it is a bid situation, I usually factor in an extra load or two depending on the size of the job. This "extra" load(s) accounts for the "extras" that people often expect in a bid situation........homeowners are good at the bait and switch maneuver when it comes to "undefined" projects......not always, but often so my advice it to plan for it and then do it even if they don't end up asking for it. This has seemed to work better for me than trying to cut everything close and be stuck doing the bare minimum work. To fill the ditch without any compaction, irregularites figured in comes out to 83yds using area of triangles(ends up being a rectangle since two triangles together eliminate the need for the divisor of 2. My equation for a fill looks something like this: [ (36" * 20")/ 144] * 450=2250cu.ft. Then 2250 cu. ft divided by 27cu. ft. gives 83.33 cu. yds. Am I still the winner!!!!

tgeb

I would agree that your calcs were good based on 1 layer of stone rip rap with some extra for loss/waste.

I simply thought the way Kubotaman worded the question, he needed 20" thick not 6" thick stone lined channel.

We just looked at the original problem differently. No offense intended C.

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Tom

www.gebcon.com

cexcavation

No offense taken TGEB This is a perfect example of how us contractors are at the mercy of wording and interpretation when it comes to bidding without plans. This is why homeowner bids are often so far across the board.

kubotaman333

sorry for the confusion and thanks for all the input. Bye the way it was just a layer not filled.

cexcavation

I say the only confusion was probably due to TGEB working too many long days in a row!!! Your description was quite clear to me, but you never know how the next guy might read something. I have bid projects where the "winner" bids a price that doesn't even cover the required materials according to what I bid. I can only assume someone misinterpreted something somewhere.........it happens.

tgeb

Yep! It's all my fault.........but I did have plenty of budget for material.

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Tom

www.gebcon.com

cexcavation

I would love bidding against you if you pad your bids that much!!!! I would even recommend you to potential customers just to make my price look that much more appealing.....Just kiddin