ᐅ Excavation work. How do you calculate gravel and soil excavation?
Created on: 16 Jan 2022 14:09
B
BenBautHello everyone,
I have received a few quotes from earthmoving contractors, but each calculates the amount of gravel and soil excavation differently. :-\
Calculations from the contractors (according to their quotes):
Gravel: 150–250 tons
Soil excavation: 250–400 tons
What do you think? How many tons of gravel and soil excavation should I expect?
- Slope location about 1.5m (5 feet)
- House dimensions 10x10m (33x33 ft). (+2x2m (6.5x6.5 ft) for scaffolding?)
- According to the soil report:
-> Recommended foundation cushion height: > 0.65m (2 ft) cushion overlap: 0.5m (1.6 ft)
-> Soil class 3–5.
-> .. do you need more information from the soil report for a rough calculation of gravel and soil excavation? Please let me know.
- Double garage on strip foundations 6x9m (20x30 ft)
- Garage driveway: 6x6m (20x20 ft)
- Terrace: 10x3m (33x10 ft)
I have received a few quotes from earthmoving contractors, but each calculates the amount of gravel and soil excavation differently. :-\
Calculations from the contractors (according to their quotes):
Gravel: 150–250 tons
Soil excavation: 250–400 tons
What do you think? How many tons of gravel and soil excavation should I expect?
- Slope location about 1.5m (5 feet)
- House dimensions 10x10m (33x33 ft). (+2x2m (6.5x6.5 ft) for scaffolding?)
- According to the soil report:
-> Recommended foundation cushion height: > 0.65m (2 ft) cushion overlap: 0.5m (1.6 ft)
-> Soil class 3–5.
-> .. do you need more information from the soil report for a rough calculation of gravel and soil excavation? Please let me know.
- Double garage on strip foundations 6x9m (20x30 ft)
- Garage driveway: 6x6m (20x20 ft)
- Terrace: 10x3m (33x10 ft)
O
Osnabruecker16 Jan 2022 15:06Compare the unit prices, not the quantities or total prices.
The quantities are then calculated approximately by volume x 1.8 for gravel.
Topsoil removal about 1.4, soil about 1.6.
Especially for the application, it is difficult to estimate accurately on a slope without detailed calculations.
What specifications do you provide for thicknesses of driveway, terrace, etc.?
Calculate roughly, but mainly compare the unit prices.
The quantities are then calculated approximately by volume x 1.8 for gravel.
Topsoil removal about 1.4, soil about 1.6.
Especially for the application, it is difficult to estimate accurately on a slope without detailed calculations.
What specifications do you provide for thicknesses of driveway, terrace, etc.?
Calculate roughly, but mainly compare the unit prices.
@Osnabruecker
Yes, I do that as well.
However, I want to prepare for the actual cost/quantity of excavation and gravel, and, as is often the case with other builders here, avoid any surprises. I've frequently heard that earthwork contractors tend to underestimate their estimates by a large margin.
Yes, I do that as well.
However, I want to prepare for the actual cost/quantity of excavation and gravel, and, as is often the case with other builders here, avoid any surprises. I've frequently heard that earthwork contractors tend to underestimate their estimates by a large margin.
O
Osnabruecker16 Jan 2022 15:15Earthworks are the hardest to estimate.
Soil surveys are only point-specific. The weight of soil varies; wet soil is even heavier per cubic meter (m3).
Every earthworks contractor calculates differently. It seems you haven’t given them any specific instructions. They won’t put in extreme effort to create terrain models for a quote. These figures are rough estimates.
You have a few quotes with different quantities. Calculate the average yourself. The median value might be accurate.
For the bank, use the highest figure and be glad for every ton that is not needed.
Soil surveys are only point-specific. The weight of soil varies; wet soil is even heavier per cubic meter (m3).
Every earthworks contractor calculates differently. It seems you haven’t given them any specific instructions. They won’t put in extreme effort to create terrain models for a quote. These figures are rough estimates.
You have a few quotes with different quantities. Calculate the average yourself. The median value might be accurate.
For the bank, use the highest figure and be glad for every ton that is not needed.
O
Osnabruecker16 Jan 2022 15:17And a good offer starts with a clear request.
One person calculates with 20 cm (8 inches) of gravel under the terrace, another with 65 cm (26 inches). This should all be clearly defined no later than the start of construction, so you don’t make the same mistake as other homeowners by just letting the earthworks contractor “do their thing” without clear instructions from the builder regarding the house and ancillary structures, driveway, crane site, and so on.
One person calculates with 20 cm (8 inches) of gravel under the terrace, another with 65 cm (26 inches). This should all be clearly defined no later than the start of construction, so you don’t make the same mistake as other homeowners by just letting the earthworks contractor “do their thing” without clear instructions from the builder regarding the house and ancillary structures, driveway, crane site, and so on.
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