Written and reviewed by the Kuesel field operations & estimating team
Last reviewed:
Kuesel is a family-owned site work and utility contractor based in O'Fallon, MO, building sites across St. Louis since 1963.
No two stabilization prices are built the same way, because no two sites are. This guide lists the factors that move a soil stabilization number up or down and explains how to put a stabilization bid and an undercut bid on equal terms. It gives no dollar figures; for a planning comparison on your own site, use our stabilization vs. undercut tool, and for how we price and build the work, see our soil stabilization services.
What drives the price
Agent type and application rate
Lime, cement and fly ash cost different amounts to buy and deliver, and the rate in the mix design sets how much of the agent goes into each area.
Treatment depth and area
Deeper treatment needs more agent and more mixing effort. Area matters both for total quantity and for how efficiently the work can run.
Mobilization and minimum production
Spreading and mixing equipment has to be brought to the site whatever the quantity, so small or scattered areas carry more mobilization per unit than large, continuous ones.
Soil moisture and water needs
Wet soils may need extra drying; dry soils may need water added to reach the target moisture. Either way, water supply and trucking are part of the cost.
Dust control and occupied-site constraints
Wind limits, neighbors, live traffic and occupied buildings can slow spreading and require extra dust control and phasing.
Testing and mix design
Lab mix design and field testing take time and coordination, and who pays for them should be clear in the bid documents.
Weather and schedule
Most specifications restrict work in freezing temperatures and high wind and require curing protection. A schedule that pushes work into marginal weather adds risk.
Haul-off and import avoided
The main reason to stabilize is often what it avoids: excavating poor soil, hauling it to a disposal site and importing replacement material.
Access and phasing
Tight sites, multiple phases and areas released one at a time each add moves and restarts.
How to compare stabilization and undercut bids on equal terms
- Price the same area and the same depth of poor soil for both options.
- Include haul-off, disposal and import material in the undercut number, not just excavation.
- Include the agent, spreading, mixing, water, compaction and fine grading in the stabilization number.
- Make testing and mix design responsibility the same for both.
- Compare schedule as well as price: trucking cycles and weather exposure differ between the two.
- Ask what happens if conditions change in the field, and how each option is paid for.
Our lime vs. cement vs. undercut guide explains the technical side of the same decision.
Questions
- Why is there no price per square yard in this guide?
- Because the drivers listed here vary so much from site to site that a general figure would mislead. Send the geotech report and plans and we can price your site.
- Is stabilization always cheaper than undercut?
- No. It often avoids haul-off and import, but deep soft zones, small scattered areas or unsuitable fill can favor undercut. Pricing both on equal terms is the way to know.
This guide is general information from a site contractor, not engineering advice. The geotechnical engineer of record and the project specification govern the stabilizing agent, rate, depth and testing on your project.