U-Fill — Unshrinkable Concrete Trucks
One Call. One Team. Get More Out.
U-Fill unshrinkable concrete — CLSM, flowable fill, utility backfill, and void filling — is one capability within OE's complete utility infrastructure offering. The same team that exposes and repairs your line can backfill and restore it, across Ontario, around the clock.
Backfill That's Part of the Job — Not a Separate Vendor
Most suppliers drop a load of fill and leave. OE places unshrinkable fill as one step in a job we already own end to end — before, during, and after the backfill. One call. One team.
One point of accountability across dig, repair, backfill, and restoration — no coordinating a separate concrete supplier, no waiting on another vendor's truck, no finger-pointing over a settled trench.
Excavation, utility work, U-Fill backfill, and restoration — all under OE.
Established relationships with municipalities, utilities, and commercial Customers.
Supplied and placed to Ontario municipal specification (OPSS 1359 / TS 13.10) — matched to the Customer's permit and reinstatement requirements.
A province-wide fleet with crews and material positioned for fast regional response.
GPS-tracked fleet for real-time response coordination.
What Is Unshrinkable Fill (CLSM)?
Unshrinkable fill — also called flowable fill or controlled low-strength material (CLSM) — is a cement-based backfill delivered and placed straight from the truck.
It flows into the trench and self-levels, filling voids and irregular spaces no compactor can reach, then hardens to a stable, low-strength material. The strength is kept deliberately low so it can still be dug out by hand or machine if a buried line ever needs future access. Because it self-compacts, it removes the lift-by-lift compaction step granular backfill requires — eliminating the settlement and trench-failure callbacks that compaction errors cause.
U-Fill Service Capabilities
From utility trench backfill to void filling, OE places unshrinkable fill to Ontario municipal spec across the province.
Controlled Low Strength Material (CLSM)
Self-compacting, excavatable backfill placed straight from the truck — no compaction, no settlement, dug out easily for future utility access.
Read More →Flowable Fill
Highly fluid cement-based fill that self-levels into voids, irregular cavities, and tight spaces a compactor can't reach.
Read More →Need unshrinkable fill on site?
Booked as part of an OE dig-and-restore job or supplied on its own — our 24/7 dispatch team is ready.
Where Unshrinkable Fill Goes to Work
From utility trench backfill to void filling, unshrinkable fill solves the jobs where compaction is slow, risky, or simply can't reach.
Utility Trench Backfill
Water, gas, hydro, and telecom trench reinstatement without compaction.
Road-Cut & Utility-Cut Reinstatement
Fast, settlement-free restoration of road and lane cuts.
Void & Cavity Filling
Abandoned tanks, vaults, and washouts filled completely with no honeycombing.
Pipe & Conduit Abandonment
Decommissioned lines filled solid to prevent future collapse.
Bridge & Culvert Backfill
Flows behind abutments and around culverts where compaction can't reach.
Tight & Hard-to-Reach Spaces
Flows around obstructions and into confined excavations.
Pipe Bedding & Encasement
Uniform support around pipe with no point-loading.
Emergency & Live-Corridor Repairs
Quick-set mixes get busy corridors reopened to traffic sooner.
One Company From Dig to Backfill
Booking excavation, U-Fill backfill, and restoration together as one OE job is where the savings show up.
One mobilization, one crew, one point of accountability instead of waiting on a separate fill supplier. Because OE runs its own integrated operations across 6 Ontario locations, coordinating fewer trucks and trips cuts travel costs and emissions — savings that land back in your project budget.
Real Work Across Ontario
A representative project type — not an actual named Customer. Full project portfolio available on request.
Watermain Trench Backfilled and Reopened the Same Day
On a municipal road-cut, OE exposed and repaired a watermain, then backfilled the trench with unshrinkable fill to municipal specification and restored the surface — all under one company. With no lift-by-lift compaction to get wrong, there was no return settlement callback, and the single-contract scope kept accountability with one team from dig to reinstatement.
More Than U-Fill — A Complete Utility Infrastructure Partner
U-Fill is one capability within OE's full service offering. Here's what else our team handles — often within the same contract, on the same site, by the same project lead.
Hydrovac Trucks
Non-destructive daylighting, slot trenching, and utility exposure — safe digging around buried gas, electric, water, and telecom.
Read More →Material Slinger Trucks
Precise placement of stone, gravel, and topsoil — including long-distance and tight-access deliveries.
Read More →Coring Trucks
Concrete and asphalt coring, utility access coring, plus full surface restoration on roads, sidewalks, and boulevards.
Read More →Traffic Control
Traffic Control Plans (TCP), lane closure permits, flagging personnel, and municipal coordination.
Read More →Turnkey SUE — Level A
Subsurface Utility Engineering — project coordination, permit applications, locate services, and site visits.
Read More →Soil Recycling
ECA-approved facility processing excavated soil into reusable products, including premium pipe bedding material.
Read More →Additional Services
Dump Trucks and Soft Services — material hauling, locates, permits, and project management that keep utility projects on schedule.
Read More →Unshrinkable Fill (CLSM) FAQ
Answers to the questions OE's sales team hears most often.
What is unshrinkable fill / CLSM?
How is it different from granular backfill?
Can it be dug up later?
Does OE's mix meet Ontario municipal spec?
How soon can a trench be reopened to traffic?
Why book U-Fill with OE rather than a separate supplier?
U-Fill Service Across Ontario
Six locations with crews positioned for fast regional response. Click any location for detailed service area information.
Request a Quote
Tell us about your project — we'll respond within 24 hours with a tailored quote and next steps. For urgent or after-hours needs, call our 24/7 dispatch line directly.