Flowable fill concrete, also called controlled low-strength material (CLSM), typically costs $100-$200 per cubic yard for delivered material, or about $150-$300 per cubic yard when placement is included. Total pricing depends on order size, mix strength, delivery distance, site access, excavation, and whether pumping or removal is needed.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Delivered flowable fill | $100/yd³ | $145/yd³ | $200/yd³ | Typical standard mix, before small-load fees |
| Placed and finished | $150/yd³ | $225/yd³ | $300/yd³ | Includes ordinary placement and basic crew labor |
| Small or restricted-access job | $500 total | $1,200 total | $3,000+ total | Minimum charges, pumping, or extra handling can dominate |
| Typical trench backfill | $600 total | $1,350 total | $3,000 total | About 4-12 yd³, depending on trench dimensions |
What flowable fill costs for common backfill jobs
For a standard commercial or residential backfill job, delivered material commonly runs $100-$200 per cubic yard. A contractor’s full price for ordering, delivery, placement, and ordinary cleanup is often $150-$300 per cubic yard. Small projects can exceed those unit rates because the supplier may charge a minimum load, short-load fee, or dispatch fee even when the required volume is low.
A practical planning figure is $225 per cubic yard installed for a moderate job with normal truck access. A 6-yard order at that rate would be about $1,350 before unusual excavation, pumping, permits, or tax. Larger orders can lower the effective price per yard, while remote sites and restricted placement can push it above the typical range.
Flowable fill is usually ordered by volume. To estimate trench volume, multiply length by width by depth in feet, then divide by 27 for cubic yards. For example, a 100-foot trench that is 2 feet wide and 3 feet deep holds about 22.2 cubic yards before allowance for irregular excavation or settlement. Contractors may add roughly 5%-10% to the calculated quantity when field dimensions are uncertain.
Assumptions: Standard non-structural CLSM mix, ordinary delivery access, typical U.S. metro labor rates, and no demolition or excavation included.
How mix, delivery, and placement shape the quote
A quote may separate the concrete supplier’s charge from hauling and field work, or combine them into a single installed rate. Ask whether the listed price includes the mix, delivery, minimum-load fees, placement crew, pumping, testing, and cleanup. Excavation and disposal are frequently separate, particularly when a contractor must remove existing soil, pavement, or failed backfill.
| Quote component | Typical price | What changes the charge |
|---|---|---|
| Standard CLSM material | $90-$160/yd³ | Mix design, cement content, local plant prices |
| Specialty mix material | $140-$240/yd³ | Higher strength, flow, set-time, or aggregate requirements |
| Delivery and short-load fees | $75-$400 per order | Order size, distance, wait time, supplier policy |
| Placement crew | $50-$100 per labor hour | Crew size, access, discharge method, schedule |
| Pump or conveyor | $500-$1,500 per day | Hose length, setup, minimum rental, cleanup |
| Excavation and haul-off | $10-$35/yd³ | Soil type, disposal location, equipment access |
Delivery minimums and access equipment can matter more than the material rate on a small pour. A supplier may require payment for a minimum quantity or bill a short-load charge when the order is below its economical truck load. Pumping is more likely to appear when the truck cannot discharge directly into the trench, behind a building, or across a long hose run.
Labor pricing depends on how the material is placed and the crew’s waiting time. A simple open trench may take a small crew a few hours, while a congested utility corridor can require traffic control, spotters, staged placement, or several truck cycles.
Trench width, depth, and mix strength change unit pricing
Volume is the largest cost driver, but trench geometry affects both the quantity and how quickly crews can place the fill. A 12-inch-wide by 2-foot-deep trench uses about 0.074 cubic yards per linear foot. A 24-inch-wide trench at the same depth uses about 0.148 cubic yards per linear foot, nearly twice as much material.
Doubling trench width can nearly double the material bill even when length and depth stay unchanged. Irregular sides, oversized excavations, and voids around pipes can increase the actual volume beyond a plan-based calculation. Contractors may also specify staged placement when a deep trench could put excessive pressure on a pipe or nearby structure.
Mix requirements affect the quote as well. Low-strength flowable fill for general backfill may cost less than a mix designed for faster set, greater early strength, or a controlled maximum strength. Specify the required compressive strength and whether later excavation is expected; a high-strength mix may be harder and more expensive to remove. Depending on the application, project specifications may call for strengths below 100 psi or mixes in the 100-300 psi range.
Distance and site conditions add costs that are not captured by a per-yard rate. A site more than 20-30 miles from the batch plant may incur higher delivery charges, while narrow streets, overhead restrictions, soft ground, or limited truck turning space can require a smaller vehicle or pump. Rush scheduling and long truck waits can also generate hourly charges.
Keep flowable fill costs down by controlling the order
Accurate dimensions help prevent both over-ordering and a costly second delivery. Measure trench segments separately, confirm depth and width with the excavator, and ask the supplier how much quantity tolerance is reasonable. For complex excavations, a contractor can calculate volume from field measurements rather than relying only on design drawings.
Coordinate excavation, inspection, and truck arrival so the load can discharge without extended waiting. Truck standby charges can accumulate when the trench is not ready, utility inspections are unfinished, or access is blocked. Confirm the placement sequence and discharge location before scheduling the batch plant.
Compare written quotes using the same mix specification, estimated cubic yards, delivery distance, and placement scope. A low material rate may exclude short-load charges or pumping, while a higher installed rate may include the crew and equipment. Request separate prices for excavation, haul-off, traffic control, and testing to identify which items are driving the total.
Order the least expensive mix that meets the engineer’s or project specification, rather than selecting higher strength without a reason. Avoid reducing cement content or changing the mix on a project where flow, support, or future excavation requirements are specified. Combining nearby pours can sometimes reduce delivery minimums, but only when timing and mix requirements are compatible.
Regional delivery rates vary with plant distance and demand
Prices differ across the country because cement, aggregate, fuel, labor, and plant availability vary by market. In lower-cost rural areas near a batch plant, delivered standard mix may fall near $90-$140 per cubic yard. Large metropolitan areas commonly land around $120-$190, while expensive coastal markets or remote locations can reach $160-$240 or more before placement.
Distance to a ready-mix plant and minimum-load policy can outweigh broad regional averages. Urban work may carry additional charges for traffic control, limited truck access, and waiting time. Rural work can face longer haul distances, fewer suppliers, or a high charge for dispatching a truck to a small project.
These are planning ranges rather than fixed regional tariffs. A contractor should confirm whether the price is based on a specific plant, whether sales tax applies, and how long the quote remains valid. Fuel surcharges or seasonal supply constraints may be listed separately, especially for deliveries outside the supplier’s normal service area.
Three example quotes for different project sizes
The examples below show how volume and access alter the total. They assume ordinary U.S. pricing and standard non-structural CLSM. Local labor rates, mix design, and supplier fees can move actual bids substantially.
| Project | Material and unit rate | Labor and other charges | Estimated total |
|---|---|---|---|
| Short utility trench, 3 yd³ | 3 yd³ at $155 = $465 | $250-$500 minimum delivery; 4-5 labor hours at $65-$90/hr | $1,000-$1,500 |
| Residential service trench, 8 yd³ | 8 yd³ at $140 = $1,120 | $300-$550 crew and delivery; minor prep $100-$250 | $1,500-$1,900 |
| Commercial utility backfill, 30 yd³ | 30 yd³ at $125 = $3,750 | $800-$1,500 placement and truck coordination; testing $200-$500 | $4,750-$5,750 |
The smallest job has the highest effective price per cubic yard because fixed charges are spread across little material. In the 3-yard example, the complete job could work out to roughly $333-$500 per cubic yard. At 30 yards, the total is closer to $158-$192 per yard, assuming no difficult access or extensive excavation.
When pumping, excavation, and testing add charges
Pumping can add several hundred to more than $1,000 when the truck cannot reach the placement area or the hose must travel a long distance. The quote should identify setup, minimum rental time, hose length, cleanup, and any charge for moving equipment between locations. A pump may be unnecessary when a chute can reach the trench safely and without disrupting traffic or adjacent work.
Ask for excavation and disposal as separate line items before accepting an installed price. Digging in ordinary soil may cost around $10-$35 per cubic yard, but rock, groundwater, buried utilities, shoring, pavement removal, or contaminated material can raise the expense substantially. Disposal fees depend on material type and local landfill rules.
Testing is project-specific. Some specifications require slump or flow checks, density-related documentation, or strength cylinders, adding roughly $200-$700 for a small project depending on the testing agency and number of visits. Not every residential backfill job needs third-party testing, but commercial, municipal, or engineered work may require it. Confirm the testing scope before bidding so competing quotes use the same requirement.
Other possible charges include traffic control, permit fees, utility locating, surface restoration, and standby time. These costs should not be assumed to be part of the concrete price. If existing pavement or landscaping must be restored after backfilling, obtain a separate estimate for that work.
Flowable fill versus compacted gravel or soil backfill
Compacted soil or granular backfill may cost less when suitable material is available on site and there is room for compaction equipment. Placed and compacted aggregate often costs about $25-$80 per cubic yard for material and delivery, plus roughly $10-$35 per cubic yard for placement, depending on grade, haul distance, and compaction needs. Excavated soil reused on site may be less expensive, although testing or imported material can change the calculation.
Flowable fill usually costs more per yard but can reduce labor and compaction effort in narrow, congested excavations. Its self-consolidating flow can fill around pipes and other obstructions where a plate compactor cannot work effectively. The project specification, pipe loading limits, and future access requirements determine whether that advantage justifies the higher price.
Traditional backfill is not automatically the cheaper choice if the trench needs several lifts, repeated compaction tests, or extensive hand work. Conversely, flowable fill may be unnecessary for a broad, accessible excavation where suitable soil can be compacted economically. Compare the complete installed cost and required performance, not only the material price per cubic yard.
Questions that prevent surprises on a flowable fill quote
Before scheduling, confirm whether the quoted rate includes material, delivery, placement, taxes, and minimum-load fees. Ask how the supplier bills waiting time and whether the estimate assumes direct chute access. Clarify the required mix strength, flow characteristics, and any limits on cement content or excavation depth specified by the engineer.
A useful quote states the estimated volume, mix specification, delivery terms, and excluded work. It should also identify who is responsible for excavation, utility protection, pump rental, testing, cleanup, and restoration. These details make it easier to compare bids that use different pricing formats.
Ask whether the contractor expects staged placement, especially around pipes or structures. Confirm if the work requires permits, inspection, traffic control, or utility coordination, and whether those costs are included. For an uncertain trench, request the unit price for additional cubic yards so the final invoice is easier to estimate if actual dimensions exceed the planned quantity.
Finally, check the quote’s expiration date and the cancellation policy. Ready-mix suppliers may charge for a dispatched truck or canceled load, and price validity can depend on cement and fuel costs. Scheduling only after the site is ready helps limit both cancellation risk and truck standby expense.