Why Deep Soil Injection Matters in Southwestern Ontario – Brosco Concrete Explains

Deep soil injection (DSI) refers to placing a substance below the soil surface using specialized equipment.

In commercial and residential contexts, DSI often involves injecting polyurethane resin or other stabilizing materials to improve soil bearing capacity.

Southwestern Ontario’s productive cropland, growing cities and aging infrastructure make it a region where DSI has become increasingly relevant.

Understanding what DSI is, how it works, who regulates it and its environmental effects helps farmers, developers and homeowners make informed choices.

In this blog, we’ll explore:

What deep soil injection is and how it works, especially in the Ontario context
Applications across industrial, residential, and commercial settings
Typical costs and technical challenges
Why Brosco Concrete uses it, and what clients should watch for

What Is Deep Soil Injection?

Deep Soil Injection service in London, ON is a ground improvement technique in which a fluid or semi-fluid material is injected under pressure into soil voids, weak zones, or beneath settling slabs.

As it expands or hardens, the injected material fills voids, displaces water, densifies soil, and can lift or level the surface above. The result is a stronger subgrade with better load bearing capacity and reduced tendency toward further settlement.

A common approach is polyurethane foam injection, where a two-component expanding foam is pushed through small-diameter injection ports into the soil.

As it cures, the foam can bond soil particles, create a solid matrix, and reduce permeability.

Because injection is deep and delivered through minimal surface disturbance, DSI is often more cost-effective and less disruptive than full excavation and recompaction, especially under existing concrete or asphalt slabs.

Brosco Concrete described it succinctly:

“Brosco Concrete uses Deep Soil Injection to restabilize soil that has eroded and is causing concrete slabs to sink. We inject an expanding polyurethane foam deep into the ground to stabilize bases for roads, parking lots and other large concrete slabs that require extra support.”

How deep soil injection works

Residential & Commercial

In residential and commercial settings, DSI is often used for:

Lifting sunken sidewalks, patios, driveways, or parking slabs
Repairing foundations that have experienced settlement
Stabilizing soils under slabs, especially in areas with clay, fill, or seasonal frost action
Voids under slabs caused by erosion or washout

Commercial settings (such as shopping malls, warehouses, or heavy-duty pavements) demand higher load capacities and longevity. DSI offers the benefit of stabilizing without large-scale demolition, facilitating minimal downtime to operations.

Construction / Infrastructure

In infrastructure projects; roads, bridge approaches, tunnels, rail, DSI can be used to:

Stabilize embankments and underlying soils
Reinforce weak layers before constructing heavy loads
Cut off subsurface seepage paths
Repair localized settlement or sinkholes beneath slabs or roadways

Because the injection can reach deep weak zones, DSI is a viable alternative to soil replacement or piling in constrained conditions.

Applications and DSI technologies by sector

Commercial, industrial and heavy infrastructure

Soil stabilization and load‑bearing improvements

Warehouses, airports, highways and railways rely on strong subgrade soils.

Polyurethane DSI is used to stabilize weak soils and lift heavy slabs without shutting down operations. The process begins with a geotechnical evaluation and dynamic cone penetration tests to identify weak layers.

Technicians then drill a pattern of holes and inject expanding foam. The resin travels along weak zones, expands to fill voids and densifies the soil matrix. Once cured, it increases load‑bearing capacity and can lift the surface back to grade.

Typical depths of 0.5–2 m and injection spacing of 1–2 m allow precise targeting of weak zones. The method addresses settlement under roads, bridge approaches, factory floors, railbeds, airport runways and grain silos.

When combined with void filling, it prevents future erosion and extends infrastructure life.

Residential development and landscaping

Tree health and landscaping

In urban areas, soil compaction around tree roots restricts air and water infiltration.

Air spading uses compressed air to loosen soil around roots. The supersonic nozzle breaks up compacted soil without damaging roots and allows arborists to apply compost backfill.

It is commonly used when older neighbourhoods are redeveloped or when construction around trees has compressed the soil.

By aerating the root zone, air spading improves tree health and reduces the risk of root rot.

Foundation stabilization and residential slabs

Uneven sidewalks, patios and basement slabs can result from weak or eroded soils.

Polyurethane resin injection offers a quick repair.

Contractors drill small (≈1 cm) holes through the concrete, insert injection ports and pump expanding foam into the soil. The foam fills voids, compacts loose soil and can lift slabs back into place.

In London, Ontario, Brosco Concrete reports that industrial slabs sagging by over 6 mm can be restored to within 2 mm of level using DSI, often in under three hours for 100 m².

Resin can lift around 20 mm per injection point and cures within minutes, minimizing downtime.

Source: https://stratalockusa.com/deep-soil-injection-process/

DSI Costs & Economic Considerations

Costs for DSI vary widely depending on site conditions, depth, soil type, injection volumes, accessibility, and project size.

Here’s a rough breakdown:

Residential slab lifting / driveway / small scale: The cost might range from CAD 10 to 25 per square foot (or more), depending on lift height and soil complexity.
Commercial / industrial slabs or pavements: Because the required strength and depth are greater, per-square-foot or per-metre costs often rise significantly.
Large infrastructure / embankment stabilization: Quoted typically on a per-cubic-metre or linear-metre basis, often in the tens to hundreds of dollars per metre, depending on depth and complexity.
Investigation and design costs: Soil testing, geotechnical assessments, and monitoring are additional overhead.
Mobilization, traffic control, and downtime costs: Particularly in commercial or infrastructure settings, these can be significant.

While DSI is more expensive upfront than patch repairs, its ability to fix the root cause of settlement, reduce future repair cycles, and minimize surface disruption often delivers better long-term value.

You can get an accurate quote for deep soil injection here.

Why Brosco Concrete Uses Deep Soil Injection

At Brosco Concrete, DSI plays a central role in providing high-value, long-lasting repairs to concrete infrastructure:

We can lift and re-level slabs such as parking lots, sidewalks, industrial floors, or roads without demolition. (Our service page mentions precisely that.)
DSI allows us to stabilize weak soils under slabs that are gradually settling, restoring structural integrity.
Because the approach is fast, precise, and minimally disruptive, construction downtime is reduced, critical in commercial or high-use properties.
The technology aligns well with Ontario conditions (freeze-thaw cycles, clay tills, variable soils) since we can reach deeper unstable layers with minimal surface damage.

For clients, it means a more efficient, durable repair with fewer headaches than full slab removal.

What Clients Should Ask & Watch For

If you’re a property owner or developer considering DSI, here are some questions and precautions:

Has a geotechnical investigation been done? To understand soil layers, groundwater, and weak zones.
What injection material is used? Ask about the chemical properties, curing strength, and warranty.
What is the injection plan (depth, spacing, volume)? You want a systematic design, not guesswork.
What quality assurance is included? Post-testing, monitoring, documentation.
Are there nearby wells, utilities, or sensitive features? The design should respect hydrological and regulatory constraints (e.g. setbacks).
What is the projected life span and maintenance expectation?
Is there proper insurance, bonding, and licensing?
Check local permits and approvals. Ensure your contractor has considered municipal, conservation authority, and regulatory compliance.

What’s Next For You

Deep soil injection is an evolving practice that offers considerable advantages for agriculture, urban development, and heavy infrastructure in Southwestern Ontario.

By placing nutrients or stabilizing materials beneath the soil surface, DSI reduces odours, runoff and surface disruption while improving nutrient efficiency and structural stability.

Provincial regulations, particularly Ontario’s Nutrient Management Act and local conservation authority programs, govern how and when farmers must inject manure, while municipal bylaws and workplace safety rules apply to construction and residential uses.

If your concrete slabs are showing signs of settlement, cracking, or unevenness, or if you have an infrastructure project with challenging soils, get in touch with us at Brosco Concrete.

We’ll walk you through the geotechnical assessment, design, and execution of a DSI solution that fits your site and budget.