Hardscaping & Landscaping Terms Glossary for Ontario Homeowners

Base & aggregate terms

Polymeric sand

Polymeric sand is a jointing sand blended with binders that harden when activated with water, locking pavers together at the joints. Once set, it resists rain washout, weeds, and ants far better than plain masonry sand. On Ontario patios and walkways it is the standard joint fill, and it should be re-topped every few years as joints open up; see our guide to polymeric sand cure time and rain risk.

3/4-clear stone (clear vs dense-grade)

3/4-clear stone is crushed stone sized to about three-quarters of an inch with the fine particles screened out, so it is open and free-draining. Because it has no fines to hold water, it does not pump or frost-heave the way limestone screenings do on clay. That is why we use a compacted 3/4-clear base under patios and driveways across Hamilton and Halton. Dense-grade, often called Granular A or limestone screenings, contains fines that hold water and is better suited to roadbeds than to residential paver bases on clay.

Compacted granular base

A compacted granular base is the layer of crushed stone placed and machine-compacted under a patio, walkway, or driveway to carry the load and resist settlement. It is built up in thin lifts, usually two inches at a time, and packed with a plate compactor so it behaves like one solid mass. The base, not the paver, is what determines whether a surface stays flat through Ontario winters.

Geotextile / non-woven fabric

Geotextile, often called non-woven landscape fabric, is a permeable sheet laid between the clay subgrade and the stone base. It lets water pass through while stopping the clay below from mixing up into and contaminating the clean stone above. On the silty clay soils common across Hamilton and Halton, this separation layer is what keeps a base from slowly turning to mud and settling.

Edge restraint

An edge restraint is the rigid border, usually aluminum or reinforced PVC spiked into the compacted base, that holds the outer pavers from spreading. Without it, the field of pavers creeps outward, joints open, and the whole surface loosens. Edge restraint lifting is the earliest visible sign of a failing interlock install, so it is the first thing to check each spring.

Site, soil & weather terms

Halton Till clay

Halton Till is the dense, clay-rich glacial soil found under much of Halton Region and the west end of Hamilton. It holds water and swells, which makes it prone to seasonal movement under anything built on top. Building on Halton Till is exactly why a free-draining stone base and geotextile separation matter so much locally, and why a thin screenings shortcut fails here fast.

Freeze-thaw

Freeze-thaw is the repeated cycle of water freezing and melting in soil, stone, and concrete through the cold season. Each cycle expands and contracts trapped moisture, working joints loose and stressing slabs and pavers. Southern Ontario sees dozens of these cycles every winter, so durable hardscaping is built to drain water away before it can freeze in place.

Frost heave

Frost heave is the upward movement that happens when water trapped in the soil freezes, expands, and lifts whatever sits on top. On Ontario clay this can shove pavers, slabs, and steps out of level over a single winter. The defence is a free-draining base over geotextile so water drains away instead of freezing under the surface.

Concrete terms

4000 PSI air-entrained concrete

This is a concrete mix rated to 4000 pounds per square inch of compressive strength with microscopic air bubbles deliberately mixed in. Those tiny air pockets give freezing water somewhere to expand, which is what lets the slab survive Ontario freeze-thaw and de-icing salt without spalling. It is the minimum mix we use on exterior driveways and slabs, and skimping below it is a common reason a poured surface fails early. For why local slabs crack, see our guide to why Ontario concrete cracks.

Control joints (saw-cut)

Control joints are the straight grooves cut or tooled into a concrete slab to tell it where to crack. Concrete shrinks as it cures and will crack somewhere, so the joints create planned, hidden break lines instead of random ones across the surface. Saw-cut joints, made with a blade soon after the pour, are cleaner and more reliable than joints tooled by hand.

Cure-and-seal

A cure-and-seal is a liquid applied to fresh concrete that slows moisture loss while curing and leaves a protective sealer behind. Curing slowly is what lets the slab reach full strength, and the sealer film then helps it resist salt, stains, and surface wear. On decorative and exterior concrete in Ontario it is a standard finishing step, with re-sealing needed every few years.

Exposed aggregate

Exposed aggregate is a concrete finish where the top paste is washed off while the slab is still green to reveal the stone within the mix. The result is a textured, slip-resistant surface that hides wear and weathers well outdoors. It is a popular finish for Ontario driveways, walkways, and pool decks; see our exposed aggregate service for examples.

Stamped concrete

Stamped concrete is a poured concrete slab textured and coloured while still wet to imitate stone, brick, or wood plank. It gives a continuous patterned surface with no joints to fill, but because it is one slab it cracks along control joints and shows wear at the colour layer over time. It is a single-pour alternative to laying individual interlock pavers.

Retaining wall terms

Geogrid

Geogrid is a stiff plastic mesh laid in horizontal layers behind a retaining wall and extending back into the compacted soil. It ties the wall to the earth behind it, turning the block face and the backfill into one reinforced mass that resists bulging and tipping. Taller segmental walls, generally over about three to four feet, need geogrid to stand safely for the long term.

Armour stone

Armour stone is large, roughly rectangular quarried blocks set in a row to hold back soil or define grade changes. Each block can weigh hundreds of pounds, so the wall relies on its own mass and a solid granular base rather than mortar. It gives a rugged, natural look and suits sloped Hamilton and Halton properties where a heavy, low-maintenance wall is wanted.

Segmental retaining wall

A segmental retaining wall is built from manufactured interlocking concrete blocks stacked without mortar over a compacted base, often with geogrid reinforcement. The dry-stacked design flexes slightly with seasonal movement instead of cracking like a rigid poured wall. It is the most common engineered wall type we build; learn more on our retaining walls service page.

Drainage & credential terms

Weeping tile / sock pipe

Weeping tile is a perforated drainage pipe laid behind a wall or under a base to collect groundwater and carry it away to daylight or a drain. A sock pipe is the same perforated pipe wrapped in a fabric sleeve that keeps fine soil from clogging the holes. Behind a retaining wall it relieves the water pressure that would otherwise push the wall over, which is why it is standard in any properly engineered wall.

ICPI certification

ICPI certification is a credential from the Interlocking Concrete Pavement Institute confirming an installer has been trained and tested on proper base preparation, edge restraint, and jointing for segmental pavers. It signals the contractor builds to a recognized North American standard rather than guessing at depths and materials. Seven Stones Landscape has been an ICPI certified installer working across the Golden Horseshoe since 2013.

Once these terms make sense, a quote stops being a mystery. You can ask any contractor to put the base depth, geotextile, edge restraint, and jointing in writing, and you will know what their answers mean. If you want a patio, driveway, or wall spec'd and built to these standards, request a free on-site estimate and we will walk through exactly what goes under the surface on your property.