Digging a Trench Cost

Last Updated on March 14, 2024
Written by CPA Alec Pow | Content Reviewed by Certified CFA CFA Alexander Popinker

Whether undertaken for installing underground utilities, constructing drainage systems, or preparing foundations for buildings and roads, trenching is an absolutely vital yet often surprisingly expensive component of many residential and commercial construction and landscaping projects.

But how much should you realistically budget for professional trenching services on a per linear foot basis for your upcoming excavation project?

We’ll thoroughly break down the many variables that influence overall per foot trenching costs, including the planned trench depth and width, the types of soils found on your site, the choice between manual and mechanical trenching methods, local labor rates, permitting requirements, and restoration considerations.

How Much Does Trenching Cost Per Foot?

Trenching costs typically range from $4-$12 per foot on average but can be higher depending on the specifics of the job, when accounting for permitting, restoration, and contingency buffers.

For small trenches up to 4 feet deep:

  • Soil excavation – $4-$6 per foot
  • Rock excavation – $8-$12 per foot
  • Backfill – $2-$4 per foot
  • Labor – $2-$5 per foot

For large trenches over 4 feet deep:

  • Soil excavation – $6-$10 per foot
  • Rock excavation – $12-$18+ per foot
  • Backfill – $3-$6 per foot
  • Labor – $3-$8+ per foot

However, the final per foot pricing for any particular project varies based on the site-specific considerations discussed earlier. Always get multiple detailed bids tailored to your unique scope!

HomeAdvisor notes that the average cost to dig 100 linear feet of trench is $800, with prices ranging from $4 to $12 per linear foot depending on the project’s complexity and materials used.

HomeGuide writes in an article that trenching costs typically range from $5 to $12 per linear foot, with an average cost of $500 to $1,200 for digging a 100-foot trench, considering factors like length, depth, soil type, and obstructions.

According to HomeBlue Contractor Network, trenching costs can vary from $13 to $24 per linear foot for machine trenching and $5 to $11 per linear foot for hand trenching, including backfilling.

The estimated cost of digging a trench per foot, according to Airtasker US, starts at $4 assuming soft ground and no obstacles, with prices potentially going up to $12 depending on the contractor and project specifics.

What Does Trenching Involve?

Trenching is the construction process of excavating long, relatively narrow channels in the ground, often in primarily linear paths, to enable the underground installation and eventual burial of important infrastructure elements such as:

  • Power, telecommunications, and fiber optic cables and wiring
  • Water, sewer, and irrigation main lines and pipes
  • Stormwater management systems and French drainage
  • Concrete footings and foundations for buildings, roads, and walls

Trenches are dug well below the maximum frost line and finished grade using heavy-duty mechanical excavation machinery like backhoes and excavators, or manually dug with hand tools like shovels when warranted.

Careful soil removal, shoring, appropriate sloping, and drainage considerations are utilized within the trenches to prevent hazardous cave-ins and accumulation of groundwater. Finally, the utilities or piping infrastructure elements are strategically placed within the trench alignment, which is then backfilled with clean fill or gravel and compacted flush to finished grade.

Factors Influencing Trenching’s Price Per Foot

Some of the major variables that affect the overall cost per linear foot for trench excavation and construction include:

  • The required trench depth and width– Much deeper and wider trenches demand substantially more soil excavation, shoring, and backfill material.
  • Soil conditions present on site – Dense compacted clay or solid rock is exponentially more challenging and costly to excavate than loose granular soils.
  • Presence of underground obstructions – Existing utilities, boulders, tree roots, and demolition debris severely slow down trenching progress which drives up project costs.
  • Manual vs mechanical trenching – Excavating entirely by hand with shovels and pick axes takes far longer than utilizing heavy machinery like excavators or specialized trenchers.
  • Local construction labor rates – In areas with higher prevailing construction wages, the per foot cost understandably trends higher as labor is a significant cost component.
  • Extensive permitting requirements – Some municipal infrastructure projects mandate extensive permitting, increasing lead times and administrative costs.

Hand Trenching vs Machine Trenching Costs

The choice between manual hand trenching and mechanical trenching using heavy equipment has a dramatic impact on project timelines and per foot pricing.

For a sample 100-foot trench four feet deep in normal soil conditions:

Manual hand trenching costs:

  • 2-3 laborers working for 3-5 days at $15-$30/hour per laborer
  • Total 100-foot cost = $2,000-$4,500

Mechanical trencher costs:

  • Trencher rental for 1 day at $250-$500/day
  • 1 trencher operator for 1 day at $200-$400/day
  • Total 100-foot cost = $500-$1,000

You might also like our articles about the cost of a backhoe, a mini excavator, or to dig a well.

Understanding the drastic time and cost differences allows informed equipment decisions for your unique project scope and limitations. Let’s see some differences:

  • Hand trenching takes 3-5 times longer for the same distance
  • Hand trenching costs 2-4 times more per linear foot
  • Hand trenching is preferred for small or obstructed sites
  • Mechanical trenching is vastly more efficient and economical for long runs

Typical Equipment and Labor Costs

Excavation equipment rental rates:

  • Small Rubber Tire Backhoe – $150-$300 per day
  • Tow-Behind Trencher – $175-$400 per day
  • Full-Sized Excavator – $200-$500 per day

Laborer rates:

  • Licensed Operator – $15-$35 per hour
  • Helper/Apprentice – $10-$20 per hour

For contractors doing frequent trenching work, owning their own equipment saves substantially on rentals long-term but has far higher initial capital costs. The hourly field labor rates make up a major portion of the per foot pricing.

Other Expenses

Quick Trench DiggingIn addition to the direct costs of the trench excavation itself using rented heavy equipment and skilled construction labor, some other common project expenses to factor into your overall budget include:

  • Municipal permitting fees – $50-$500+
  • Trench shoring and mandated safety measures – $200-$2,000
  • Environmental site assessments and impact studies – $500-$5,000+
  • Comprehensive landscaping and surface restoration – $10-$20+ per linear foot depending on vegetation

Many clients, unfortunately, underestimate the potential for substantial compliance expenses and significant post-project restoration work. Thoroughly account for these contingencies in your trenching budget.

Strategies to Reduce Trenching Costs

Some ways project owners can seek to minimize trenching costs through value engineering include:

  • Soliciting competitive bids from at least 3 local excavation contractors to compare pricing
  • Optimizing trench placement and layout to be as linear and accessible as possible
  • Timing the project for the off-season when excavation contractors offer lower rates
  • Utilizing trenchless technologies like horizontal directional drilling wherever feasible to minimize trenching
  • Considering reusing excess trench spoil material for non-structural trench backfilling depending on composition

With careful planning, resourcefulness, and flexibility, significant cost savings can often be realized on major trenching projects to stay on budget.

Choosing an Experienced Trenching Contractor

When choosing an excavation contractor for your upcoming trenching project, be sure to evaluate:

  • Years of demonstrated experience successfully completing similar scale projects
  • Competitive yet transparent per foot trenching rates and quoting
  • Track record of stellar safety compliance and zero serious incidents
  • Proof of up-to-date insurance, bonding, licensing, and workmanship warranties
  • Strong reputation for responsiveness, communication, timeliness, and attention to detail

Rather than simply choosing the contractor offering the lowest bid, seek out technical expertise, proven safety, and shared project vision.

Final Words

While prices vary based on many factors, trenching costs range $5-$15 per foot on average when considering equipment, labor, permitting, and restoration expenses. With diligent cost estimation and a qualified contractor, your trenching project can be executed smoothly, safely, and cost-effectively.

Frequently Asked Questions

How long does it take to trench 100 feet with a trencher?

With decent soil conditions and an experienced operator, you can expect a productivity rate of 100-150 linear feet of trenching per hour from a standard walk-behind trencher on average. Larger tow-behind trencher models average closer to 200-300+ feet of trench excavation per hour under ideal conditions.

Total trenching speed per hour is affected substantially by the soil type, specific trench dimensions, presence of buried obstacles, and depth.

How many feet can you trench in an hour?

In relatively loose, non-rocky native soil, manual trenching with just shovels and hand tools averages approximately 30-50 linear feet of excavation per hour based on the trench dimensions.

A proficient backhoe or full-sized excavator operator can usually trench 60-100+ linear feet per hour once the digging depth is reached. Overall, per-hour productivity depends greatly on the soil composition, precise width, and depth, terrain accessibility, and whether any unexpected buried obstructions are encountered.

How deep should a trench be?

For electrical and telecommunication cables, trenches need to be dug at least 18-24 inches below the finished grade for secure burial. Water lines and sewer piping require significantly deeper trenches around 48-60 inches deep minimum to prevent any risk of freezing.

Be absolutely certain to follow all local building codes and utility company standards for the mandated burial depth requirements for each type of infrastructure line being installed to avoid rework.

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