Natural armour stone retaining wall with landscaped greenery above

Armour Stone · Retaining Walls · Steps · Ottawa

Ottawa Armour Stone That Holds Its Ground — and Lifts Your Property

Big stone does big work. A well-built armour stone retaining wall turns a slope you can’t use into a level yard you’ll live in, holds back soil that wants to move, and gives the front of your home the kind of permanent, natural weight that concrete block never quite matches. We design, supply, and install armour stone across Ottawa — retaining walls, garden steps, entrance features, culvert ends, and standalone accent boulders — engineered for this region’s clay soils and deep winter frost.

Book Your On-Site Assessment Call (613) 324-9141

A no-cost, no-obligation on-site assessment before any numbers are discussed.
A written, fixed-price quote after we’ve measured the grade and checked access.
Engineered drawings arranged for any wall over one metre of exposed height, and the City of Ottawa building permit handled end to end.
A properly drained base on every wall — compacted aggregate, filter fabric, clear stone, and drainage — with all project documentation available on request.

Large rough-cut natural armour stone blocks stacked in a wall

About Amour Stone Ottawa

Armour stone is a specialty, not a sideline

It is natural quarried rock — usually limestone or granite drawn from Ontario and Quebec quarries along the Canadian Shield — cut into large, roughly rectangular blocks that can weigh anywhere from a few hundred pounds to well over a tonne each. Moving it safely, seating it level, and building a structure that will pass inspection and stand for decades takes dedicated equipment and hands-on experience that general landscapers often don’t carry. Many crews simply can’t lift a one-tonne block, let alone stack a wall that drains correctly and resists frost. That gap is exactly where we work.

We’ve spent years of hands-on work placing heavy stone across the Ottawa region, and we’ve learned the local ground the hard way — on real sites, in real conditions. We know how Leda clay behaves when it gets wet, how a narrow side-yard gate changes an entire install plan, and why a wall that looks fine in October can lean by April if the drainage was skipped. Armour stone is what we do, and doing one thing well is the whole point of specialization: fewer surprises, cleaner builds, and a finished feature that behaves the way natural stone is supposed to — quietly permanent.

We also work alongside interlock and precast when a design calls for it, and we regularly handle the heavy-rock portion of projects that other Ottawa landscape designers would rather hand off. Whether you want a single sculptural boulder as a garden focal point or a multi-tiered retaining system reshaping an entire backyard, the approach is the same: measure carefully, build on a proper base, and put the commitment in writing.

Why Choose Us

Why Ottawa Homeowners Choose Us for Armour Stone

Armour stone is our specialty

Heavy natural stone is the core of what we build. That focus means the right clamps and machinery to move large blocks without damaging your yard, and the placement experience to seat each stone so the wall reads as one solid mass rather than a stack of rocks.

Permits and engineering handled for you

Any retaining wall over one metre (about 3 ft 3 in) of exposed height in Ottawa requires a building permit and a design sealed by a Professional Engineer (P.Eng.). We arrange the engineered drawings and manage the City of Ottawa permit application end to end, so the structural responsibility for taller walls sits where it should.

Built for Ottawa’s climate and soils

Deep frost and reactive clay are the two forces that break local landscape structures. We build with those forces in mind — proper footing preparation, granular base, and drainage that keeps water from freezing into heave-generating ice lenses behind the wall.

Documented quality steps on every wall

Our walls start with excavation to a stable base, then compacted aggregate, non-woven filter fabric, clear stone backfill, and drainage before the face stone ever goes down. These aren’t upsells; they’re the standard construction sequence, and the documentation is available on request.

Engineering included where it’s required

For walls that cross the one-metre threshold or sit in complex conditions — near a property line, above a driveway, or on poor soil — engineered structural drawings are part of the package, not an afterthought discovered halfway through the dig.

Fixed price and a written warranty

You get a written, fixed-price quote after an on-site assessment, and a written warranty delivered with your project close-out. What you sign is what you pay, barring the documented exclusions every honest quote carries (permits at cost, unforeseen ground conditions).

Our Services

Armour Stone Services We Offer in Ottawa

Below are the armour stone services we build most often, each with an indicative price range based on published 2025–2026 Ontario-market pricing for natural-stone landscape work. Ranges are starting points for planning only — your price is the written quote you receive after an on-site assessment. See the pricing summary and disclosure block that follow for what these ranges include and exclude.

Stacked natural armour stone retaining wall

Armour Stone Retaining Walls

The workhorse of armour stone landscaping. Retaining walls hold back soil on sloped lots, create level, usable space for a patio or lawn, and protect foundations and grades from erosion. In Ottawa they’re especially common on the rolling terrain near the Rideau Canal and Ottawa River. Installed cost for natural stone / armour stone walls typically runs about $35–$65 per square foot of wall face; a straightforward 50-foot wall at 3 feet high (roughly 150 sq ft of face) commonly lands in the $3,750–$7,500 range before engineering and permits. Taller walls need heavier blocks, deeper bases, and engineering, which moves the figure up.

Indicative: $35–$65 / sq ft of wall face

Broad natural stone garden steps with greenery

Armour Stone Garden & Entrance Steps

Single large blocks make broad, solid, slip-resistant treads that are as durable as they are handsome — ideal for changes in grade at an entrance or through a sloped garden. Natural-stone step treads generally run about $300–$550 each installed, and a typical set of three to four steps often falls between roughly $1,500 and $4,000 depending on width, rise, and access.

Indicative: $300–$550 per tread installed

Large natural accent boulders placed on a grassy yard

Accent Boulders & Garden Focal Points

Not every yard needs a full wall. A single well-chosen boulder can anchor a garden bed, mark a driveway entrance, or simply give you a natural place to sit. Ornamental and accent stones are the most budget-flexible option — individual stones are commonly sold in the range of about $60–$195 each depending on size, with placement priced by access and equipment needs.

Indicative: $60–$195 per stone

Stone wall edging along a tree-lined driveway

Driveway Edging & Culvert Ends

Armour stone makes crisp, permanent edges along driveways and dresses up culvert ends at rural and semi-rural entrances — a common need in Ottawa’s outlying communities. Pricing depends on linear footage and stone size; we quote it as part of your overall site plan.

Quoted by linear footage & stone size

Natural rock terraces stepping up a slope with a tree

Terraced & Tiered Retaining Systems

On steeper slopes, two or more shorter walls with a planted terrace between them often look better than one tall wall — and, when each tier stays under a metre, can sometimes change the permit picture. Tiered systems typically cost more overall than a single wall of equivalent height (often 20–50% more) because each tier needs its own base preparation and drainage.

Indicative: 20–50% above a single equivalent wall

Waterfall cascading over dark natural stone

Pond, Waterfall & Water-Feature Stonework

Large stone frames water beautifully. Simple stone cascades start modestly, while multi-tiered water features with pumps, basins, and lighting scale well upward. We build the stonework and coordinate the water components as your design requires.

Basic features indicative from $2,000+

Large stone armouring a slope for erosion control

Erosion Control & Grade Stabilization

Flooding and heavy rain events are becoming more common around Ottawa, and armour stone is a proven tool for diverting water, armouring shorelines and swales, and stabilizing slopes that keep slipping. We assess the drainage pattern first, then place stone to move water toward — not away from — where it belongs.

Quoted after drainage assessment

Designed garden with lush planting and a stone path

Design, Supply & Stone Selection

Every project begins with selecting the right stone: the colour, size, and texture that suit your home and grade. We help match limestone or granite tones to your property and translate your ideas into a buildable plan before a single block is delivered.

Included in every project

Transparent Planning Numbers

Indicative Pricing Summary

The table below collects indicative ranges for our most-requested armour stone services, benchmarked against published 2025–2026 Ontario-market pricing for natural-stone landscape work. Read it alongside the disclaimer and disclosure block underneath.

Armour stone retaining wall (installed)

$35–$65 / sq ft of wall face

Retaining wall — typical 50 ft × 3 ft (≈150 sq ft face): $3,750–$7,500 before engineering and permits.

Natural-stone steps (per tread, installed)

$300–$550 each

Set of 3–4 stone steps

$1,500–$4,000

Accent / ornamental boulders (per stone)

$60–$195 each

Tiered / terraced retaining system

20–50% above a single wall of equal height

Basic water feature add-on

from $2,000+

Engineering (P.Eng. sealed drawings, walls over 1 m)

$1,000–$3,000 (at cost)

City of Ottawa building permit (typical)

Billed at cost per the City fee schedule

What moves your price. Several real factors push a quote up or down within — or beyond — these ranges: wall height (the single biggest driver, because taller walls need heavier blocks, deeper footings, and engineering); total length; site access (a gate narrower than about 8 feet can force craning stone over the house or hand-carrying smaller pieces, both premium scenarios); drainage complexity; the stone type and finish you choose; ground conditions revealed during excavation; and whether steps, caps, lighting, or water features are added. Difficult access alone can add roughly 10–30% to a project.

Full pricing disclosure. Indicative ranges above are for planning and describe the general Ottawa/Ontario market — they are not a quote for your project and are not an offer to contract. Unless your written quote states otherwise, ranges exclude: building permit fees (billed at cost); engineering and P.Eng. sealed drawings (billed at cost); HST; disposal of excavated soil or demolition of an existing structure; and any unforeseen ground conditions such as buried debris, rock, or unstable soil discovered once work begins. Your price is the written, fixed-price quote you receive after an on-site assessment — that document, not this page, governs what you pay.

Real Local Conditions

Common Problems We Solve

A sloped yard you can’t actually use

Ottawa’s rolling terrain leaves many homeowners with a backyard that drops away too steeply for a patio, a play area, or a garden. A retaining wall — or a tiered set of walls — carves that slope into level, usable ground and holds it there.

Soil erosion against the foundation

When grade runs toward the house, every rainfall pushes soil and water at your foundation. Properly placed armour stone redirects that flow and armours the vulnerable areas, protecting the most expensive part of your property.

Frost heave lifting and cracking structures

Ottawa ground frost regularly reaches 1.2 metres and can penetrate to about 1.5 metres in exposed areas. Any structure founded above that active zone gets pushed upward unevenly. We build bases and drainage designed to keep water from freezing into the ice lenses that generate heave.

Reactive Leda clay that swells and shrinks

Much of Ottawa sits on sensitive Champlain Sea (Leda) clay, which expands when wet and shrinks when dry, creating uneven pressure under anything built on it. Sound base preparation and drainage are the difference between a wall that stays put and one that moves with the seasons.

Standing water and poor drainage

Clay doesn’t drain. Water that pools behind a wall builds hydrostatic pressure — the number-one cause of retaining-wall failure. Our walls include filter fabric, clear-stone backfill, and drainage so water has somewhere to go before it becomes a problem.

A tired entrance or flat, featureless yard

Sometimes the problem is simply that the property looks ordinary. A single sculptural boulder, a run of stone steps, or a low garden wall adds natural character and lasting curb appeal that lifts the whole property.

Homeowner Checklist

Getting Armour Stone Right

The standard we work to

Excavation to a stable subgrade before any stone is placed — no building on soft or organic soil.
A compacted granular base sized to the wall, not a token layer of gravel.
Non-woven filter fabric between soil and backfill to stop fines from migrating and clogging drainage.
Clear-stone backfill and a drainage path (weep points or perforated pipe) on every wall, including short ones.
Engineered, P.Eng.-sealed drawings and a City of Ottawa permit for any wall over one metre of exposed height.
Guards where the Ontario Building Code requires them — for example, a retaining wall adjacent to a driveway or public access with an open drop at the top.

Questions to ask any contractor before you sign

How will you prepare and compact the base, and how deep will you excavate?
What drainage are you installing behind the wall — filter fabric, clear stone, and pipe?
Is my wall over one metre of exposed height, and if so, who is providing the engineered drawings and pulling the permit?
Will I receive a written, fixed-price quote and a written warranty?
How will you get equipment and stone to the work area given my site access?
Can you provide project documentation showing the base and drainage were built as specified?

Any reputable Ottawa stone contractor should answer all six without hesitation. If drainage or base preparation gets waved off as unnecessary on a “small” wall, treat that as a warning sign — skipped drainage is the most common reason short walls fail early.

How It Works

Our Process, Step by Step

Step 1

On-site assessment (no cost, no obligation)

We visit your property, look at the grade, check access, and talk through what you want to achieve. This is where a realistic plan starts.

Step 2

Design and stone selection

We translate your goals into a buildable design and help you choose the stone colour, size, and texture that suit your home and grade.

Step 3

Written, fixed-price quote

You receive a clear written quote — typically within a few business days of the assessment — with the scope, the stone, and the price spelled out.

Step 4

Engineering and permits (where required)

For walls over one metre or in complex conditions, we arrange P.Eng.-sealed drawings and handle the City of Ottawa building permit application end to end.

Step 5

Base construction and drainage

We excavate to a stable subgrade, build and compact the granular base, and install filter fabric, clear-stone backfill, and drainage before face stone is set — with inspection stages as the permit requires.

Step 6

Stone placement, finishing, and close-out

We set and level each block, finish the surrounding grade, clean the site, and deliver your written warranty and project documentation on completion.

Have a project in mind? Call (613) 324-9141 or use the contact form to book step one.

Book Your Assessment

Where We Work

Areas We Serve Across Ottawa

We build armour stone projects throughout the City of Ottawa and its surrounding communities, from established central neighbourhoods to the rural edges where culvert ends and driveway edging are everyday work. Areas we serve include:

Barrhaven

Kanata

Nepean

Orléans

Stittsville

Gloucester

Cumberland

Manotick

Greely

Riverside South

Findlay Creek

Hunt Club

Alta Vista

The Glebe

Old Ottawa South

Old Ottawa East

Westboro

Hintonburg

Centretown

Sandy Hill

Vanier

Rockcliffe Park

Rothwell Heights

Blackburn Hamlet

Beacon Hill

Bells Corners

Carp

Richmond

Osgoode

Metcalfe

North Gower

Constance Bay

Dunrobin

Navan

Munster

Fitzroy Harbour

Don’t see your neighbourhood listed? If you’re in the Ottawa area, call us — we very likely cover you. All of our work stays within Ontario; we don’t take armour stone projects across the river into Quebec.

Local Knowledge

Ottawa Armour Stone: Local Area Guide

Building heavy stone in Ottawa means building for specific local rules and ground conditions. Here’s the practical background every homeowner should know before starting a project.

When you need a permit

In Ottawa, a retaining wall over one metre (about 3 ft 3 in) of exposed height requires a City of Ottawa building permit. Walls under a metre generally don’t require a permit but still must respect zoning setbacks. The Ontario Building Code also treats certain walls as “designated structures” — for instance, a wall adjacent to public property, a building entrance, or an area the public can access — which brings permit and guard requirements into play even when the wall itself sits on private land. We assess which rules apply to your specific site during the on-site visit.

Engineering requirements

Walls over one metre of exposed height in Ottawa must be designed by a Professional Engineer (P.Eng.), who provides sealed drawings specifying wall dimensions, reinforcement, drainage, and foundation. Engineering fees typically run about $1,000–$3,000 depending on wall complexity, soil, and access. For anything near a property line, above a driveway, or on poor soil, an engineer’s involvement is wise even below the one-metre line.

Frost depth and why it dictates the base

The Ottawa–Gatineau region sees deep frost: ground frost regularly reaches about 1.2 metres and can penetrate to roughly 1.5 metres in exposed areas — deeper than Toronto’s typical 1.2-metre line. Structures founded above that active zone get lifted by frost heave. For heated foundations the Code minimum is 1.2 metres below grade, and in poor-draining Leda clay areas engineers may call for placement closer to 1.5 metres. It’s the reason a stone structure’s base and drainage matter far more here than in milder cities.

Leda clay: Ottawa’s defining soil

Much of Ottawa is built on sensitive marine clay — Leda clay, also called Champlain Sea clay — deposited when the sea covered this valley after the last ice age. It’s highly frost-susceptible because of its silt content and moisture retention, and it swells when wet and shrinks when dry. Capillary rise in this clay can exceed three metres, continuously feeding ice lenses from below the frost line. Practically, that means drainage isn’t optional and the base must be built to tolerate a soil that moves.

Drainage is the whole ballgame

Inadequate drainage is the number-one cause of retaining-wall failure everywhere, and Ottawa’s clay makes it worse — water that can’t escape builds hydrostatic pressure that bows and topples walls. Every wall we build includes clear-stone backfill, filter fabric, and a drainage path, and we grade the surrounding soil to move water away from both the wall and your foundation. Where flooding risk is high, we design the stonework specifically to divert water toward the drainage system.

Where the stone comes from

Ottawa armour stone is natural quarried rock — limestone and granite drilled and blasted from Ontario and Quebec quarries along the Canadian Shield. It arrives in large, roughly rectangular blocks in a range of sizes and earth tones, and it is naturally resistant to wear and erosion, which is why a properly built armour stone wall can outlast almost anything else in your yard. Concrete block and natural stone walls commonly last 50 years or more when the base and drainage are done right.

In Their Words

What Ottawa Homeowners Say

“Our backyard in Barrhaven dropped off so steeply we’d basically given up on it. The tiered walls turned it into a flat, usable space we actually spend time in now. The crew explained the drainage step by step.”

— Homeowner, Barrhaven

“They handled the engineered drawings and the city permit for our front wall so we didn’t have to chase any of it. The written quote was exactly what we paid.”

— Homeowner, Alta Vista

“A single big limestone boulder at the end of the driveway completely changed how the property looks. Small job for them, big difference for us.”

— Homeowner, Manotick

“We had water pooling against the foundation every spring. The regrading and the stone swale they built finally sent it the other way.”

— Homeowner, Orléans

“I design landscapes but don’t have the equipment for heavy rock. I bring them in for the armour stone portion and it’s always seated properly and on time.”

— Local Landscape Designer, Ottawa

“The steps into our sloped garden are solid as bedrock and wide enough to walk two-abreast. Two winters in and nothing has shifted.”

— Homeowner, Kanata

“What I appreciated most was the honesty about access — they told us upfront the narrow gate meant craning stone, and priced it clearly instead of springing it on us later.”

— Homeowner, The Glebe

Straight Answers

Frequently Asked Questions

What is armour stone?+

Armour stone is large natural quarried rock — usually limestone or granite from Ontario and Quebec quarries — cut into big, roughly rectangular blocks used for retaining walls, steps, edging, and accent features. Individual stones can weigh from a few hundred pounds to well over a tonne.

Do I need a permit for an armour stone retaining wall in Ottawa?+

If the wall has more than one metre (about 3 ft 3 in) of exposed height, yes — Ottawa requires a building permit and an engineered design by a P.Eng. Walls under a metre usually don’t need a permit but must still meet zoning setbacks, and certain walls near public property or building access count as “designated structures” with their own requirements. We confirm what applies to your site during the assessment and handle the permit for you.

How much does an armour stone retaining wall cost in Ottawa?+

As an indicative guide based on published 2025–2026 Ontario-market pricing, installed natural-stone walls run about $35–$65 per square foot of wall face; a typical 50-foot wall at 3 feet high lands around $3,750–$7,500 before engineering and permits. Your actual price is the written quote you receive after an on-site assessment.

Why is drainage so important behind a wall?+

Water trapped behind a wall builds hydrostatic pressure, which is the single most common cause of retaining-wall failure. In Ottawa’s clay soils water drains poorly, so every wall we build includes filter fabric, clear-stone backfill, and a drainage path to relieve that pressure.

How deep does the base need to go because of frost?+

Ottawa ground frost regularly reaches about 1.2 metres and can hit roughly 1.5 metres in exposed areas. Base preparation and drainage are designed around that active frost zone so the structure isn’t lifted by heave. For heated foundations the Code minimum is 1.2 metres below grade, and poor-draining clay can push that toward 1.5 metres on engineering advice.

What is Leda clay and why does it matter?+

Leda (Champlain Sea) clay is the sensitive marine clay much of Ottawa sits on. It swells when wet, shrinks when dry, and is highly frost-susceptible — so it moves with the seasons. That’s why proper base construction and drainage are essential for anything built on it to stay stable.

How long does an armour stone wall last?+

Built correctly on a proper base with good drainage, natural stone and concrete-block walls commonly last 50 years or more. Armour stone itself is naturally resistant to wear and erosion, so the lifespan usually comes down to the quality of the base and drainage beneath it.

Can you build on a difficult or narrow-access site?+

Usually, yes — but access changes the plan and the price. If your gate is narrower than about 8 feet, we may need to crane stone over the house or move smaller pieces by hand, which we price transparently. Difficult access can add roughly 10–30% to a project, and we’ll tell you upfront.

Do you build tiered or terraced walls?+

Yes. On steeper slopes, two or more shorter walls with a planted terrace between them often look better and can sometimes keep each tier under the one-metre permit threshold. Tiered systems typically cost 20–50% more than a single wall of the same total height because each tier needs its own base and drainage.

Can armour stone be used for steps and entrances?+

Absolutely. Large blocks make broad, solid, slip-resistant treads that suit grade changes at entrances and through gardens. Natural-stone treads generally run about $300–$550 each installed, with a set of three to four steps often between $1,500 and $4,000 depending on width and access.

Do you install just a single boulder, or only big projects?+

Both. A single accent boulder as a garden focal point is a perfectly good project, and often the most budget-friendly way to add natural character. Individual stones commonly run about $60–$195 each, with placement priced by access.

Do you offer a warranty?+

Yes. You receive a written warranty delivered with your project close-out, and project documentation showing the base and drainage were built as specified is available on request.

How soon can I get a quote?+

After a no-cost, no-obligation on-site assessment, we typically provide a written, fixed-price quote within a few business days. Call (613) 324-9141 or use the contact form to book the assessment.

Do you work in Gatineau or across the river in Quebec?+

No. All of our armour stone work stays within Ontario and the City of Ottawa and its surrounding communities. We don’t take projects across the river into Quebec.