The masonry trade is older than most things humans build with. Brick has been fired and stacked for nine thousand years. Stone has been cut and set for fifteen thousand. The tools, the materials, and the surrounding ecosystem have evolved, but the basic act — a mason placing a unit on mortar, plumbing the wall, tying it to the structure, letting it cure — has not. We are a Toronto masonry contractor and this is a homeowner’s-eye write-up of what masons actually do, what the trade covers, what materials and masonry products we work with, and what good masonry construction looks like up close.
Who is a mason and what they do
A mason is a tradesperson who builds with brick, stone, or concrete block, bonded with mortar. The work splits across several specializations:
Bricklayer. Sets fired clay brick on mortar. Most residential exterior masonry in the GTA is bricklaying — face brick veneer, garden walls, chimney rebuilds, fireplace surrounds. Standard tools: trowel, level, line, jointer, brick hammer.
Stonemason. Sets natural stone on mortar (or sets it dry). Selects each stone for its bedding plane and fit, shapes pieces with chisels and saws when needed. Heritage and high-end residential stone work, full-bed cladding, dimension stone walls. Tools include the standard masonry kit plus stone-specific chisels, mauls, and pneumatic carving tools.
Refractory mason. Specializes in firebox and high-temperature work. Sets fireclay refractory brick (ASTM C27) with refractory mortar (ASTM C199, calcium aluminate-based) for fireplaces, kilns, and industrial furnaces.
Block layer. Sets concrete masonry units (ASTM C90) on Type S or Type M Portland mortar. Foundation walls, structural commercial walls, retaining wall backers, garden walls.
Restoration mason. Specializes in heritage repair — repointing pre-1930 brick and stone walls, dutchman repair, profile matching, salvage brick installation. Works in NHL5 hydraulic lime mortar where Portland would damage soft heritage masonry.
Most working masons in Toronto cover at least two of these specializations. We run brick, stone, and refractory scope on the same crews. Restoration is an additional skill set carried by senior masons on the team. Every project draws on the right mix of skills.
What masonry actually covers as a trade
The word “masonry” covers a wide range of construction. The common thread is that the work involves laying solid units (brick, stone, concrete block) on mortar to form walls, floors, columns, or other structural and decorative elements.
Categories we run weekly across the GTA:
Exterior wall construction. Full-bed brick or stone envelopes on custom homes. Single-wythe brick veneer over wood framing on standard residential. Concrete block backup walls behind exterior brick or stone.
Restoration and repointing. Joint-by-joint mortar replacement on heritage walls. Brick replacement where individual pieces have failed. Lintel reconstruction (BIA Technical Note 31B for steel-lintel rust-jacking). Full elevation rebuilds where extensive damage has compounded.
Fireplace and chimney masonry. Wood-burning firebox construction, surround building, chimney rebuilds from the roof line, full chimney installation. Refractory firebrick lining inside the firebox; standard face brick or stone on the surround and stack.
Window sills, lintels, and trim. Heritage profile matching. Modern brick or stone sill installation. Lintel rebuilds where steel has corroded and damaged the brick course above.
Retaining walls and landscape masonry. Segmental concrete blocks (Allan Block, Unilock, Permacon). Natural stone gravity walls. Armour stone installations. Reinforced concrete cantilever walls for taller scope.
Hardscaping. Flagstone patios and walkways. Stone walkway construction. Brick pillars and columns. Stone steps and treads.
Heritage facade work. Pre-1930 brick and stone restoration. NHL5 hydraulic lime mortar. Dutchman repair on cut limestone elevations. Salvage brick matching for Don Valley red and Cooksville stock.
The masonry trade is broader than most homeowners realize. A real masonry contractor handles all of it.
Materials and masonry supply masons actually use
A masonry crew shows up with a specific list of products from one of several Ontario masonry supply yards. Knowing what they are helps homeowners understand what they’re paying for. Most GTA masonry supply runs through Brampton Brick distributors, Mason’s Masonry Supply Ltd in Mississauga, Belden Brick yards, and the regional yards run by Dufferin, Lafarge, and CRH Canada.
Face brick (ASTM C216). Standard fired clay brick. Brampton Brick, Glen-Gery, Cooksville stock. Modular dimensions roughly 7.5 by 2.25 by 3.5 inches. Most GTA residential and small commercial uses ASTM C216.
Engineering brick (ASTM C652). Higher compressive strength (70+ MPa typical), lower water absorption, used where structural performance carries the spec.
Refractory firebrick (ASTM C27). Firebox lining only. Rated 1700 to 2000 °F continuous service.
Salvage and reclaimed brick. Don Valley red (Don Valley Brick Works closed 1989). Bowman Masonry, Arcana Materials, Cap Brick Vintage carry period-correct stock for heritage matching.
Natural stone. Indiana limestone (ASTM C568, the heritage benchmark used on Royal Bank tower at Bloor and Yonge and Old City Hall). Eramosa limestone. Owen Sound Ledgerock sandstone (ASTM C616). Wiarton dolomite. Granite (ASTM C615).
Concrete masonry units (ASTM C90). Standard concrete block, hollow or solid. Foundation walls, commercial structural walls, garden wall backers.
Mortar (ASTM C270). Type M (17.2 MPa, structural foundations). Type S (12.4 MPa, load-bearing exteriors). Type N (5.2 MPa, above-grade non-load-bearing — most residential face brick). Type O (2.4 MPa, interior repair).
NHL5 hydraulic lime mortar. Pre-1930 heritage walls. Softer than the pre-1930 brick around it, designed to fail before the brick does. Cited by Toronto Heritage Preservation Services on every HCD scope.
Refractory mortar (ASTM C199). Calcium aluminate-based. Firebox joints only. Maximum 1/4 inch joint thickness per NFPA 211.
Reinforcement. Hot-dip galvanized brick ties (every 16 inches vertical, 32 inches horizontal on veneer walls). Stainless steel ties for high-exposure work. Horizontal joint reinforcement (ASTM A951) on tall walls. Vertical rebar in CMU cores on reinforced masonry.
The list is longer than most clients expect. The right combination of materials for a wall depends on its structural role, exposure, and the building’s era.
What separates good masonry from bad
Three things show up consistently on walls that last a century, and absence of any one shows up consistently on walls that fail in a decade.
Right mortar for the substrate. Hard Portland cement on soft pre-1930 brick is the most common cause of premature heritage wall failure in Toronto. The mortar becomes harder than the brick around it, and the brick cracks first. NHL5 hydraulic lime is the right call on heritage walls. National Park Service Brief 2 covers the physics.
Real flashing and weep holes. Every horizontal interruption in the wall (sills, lintels, decks, roof intersections, foundation top) needs flashing and weep holes. Without them, water that gets behind the masonry cannot escape and freeze-thaw destroys the wall from the inside.
Proper substrate prep on cladding work. Stone and brick veneer over framing requires a water-resistive barrier (Tyvek, Typar, two layers of Grade D paper), a drainage mat behind the lath, and mechanical fastening of the lath into framing studs. CSA A371 sets these requirements. Most veneer failures we see in the GTA trace back to skipped substrate prep.
The fourth factor is the mason’s eye. Plumb walls. Tooled joints. Course alignment. The visible craft of the work. A good mason produces walls that read straight, even, and intentional from twenty feet and up close.
How a masonry project actually runs
Sequence is consistent across scope sizes:
Site visit and quote. A real mason walks the project, measures, asks about use, and identifies hidden risks before quoting. Photographs everything. Quote arrives line-itemed.
Permits. Structural masonry triggers a permit under Ontario Building Code Section 9.20 or 9.22. Heritage Conservation District scopes need HPS approval. We file the masonry-specific portion; the architect or general contractor handles the umbrella permit.
Material delivery. Brick and stone arrive on pallets. Mortar dry mix in bags. Sand and aggregate in bulk. Most of our work involves coordinating one or two material drops to the site.
Build phase. Excavation if needed. Foundation or footing pour. First course set on a full mortar bed, plumbed and levelled. Subsequent courses laid on 3/8 to 1/2 inch mortar beds. Joints tooled to spec. Reinforcement installed where required.
Cure. Mortar reaches full strength at 28 days. The wall can be loaded earlier, but full design strength requires cure time.
Walk-through. Documentation of the scope, what was used, what to watch for in the first decade, scheduled check-in for any settlement.
A residential exterior wall masonry phase typically runs 4 to 12 weeks. A heritage repointing scope runs 1 to 4 weeks. Single chimney repair: 2 to 7 working days.
How to tell a real mason from a generalist
The Toronto market has a wide range of contractors who advertise masonry work. The work quality across the range is also wide. Three checks separate working masons from generalists:
Standards literacy. Ask which ASTM mortar type fits your wall. The answer comes back fast from a working mason. The wrong answer is “we just use what works.”
Project log. A real mason has a recent active project log of completed work in named neighbourhoods, with photographs. Heritage scopes need HPS-approved precedents.
Material specificity. A mason names brick brands (Brampton Brick, Glen-Gery, Cooksville), stone quarries (Owen Sound Ledgerock, Eramosa), salvage suppliers (Bowman Masonry, Arcana Materials). A generalist names “brick” without specifics.
The masonry construction industry in Ontario is not licensed in the same way as electrical or gas work. There is no “masters masonry license” required to call yourself a mason in this province. That makes the standards-literacy check, the project-log review, and the material-specificity test the three most reliable filters when picking a contractor.
Heritage masonry and Toronto context
Toronto’s heritage residential masonry — Cabbagetown, the Annex, Riverdale, Roncesvalles, Leslieville, much of Forest Hill, parts of Rosedale and Parkdale — was almost entirely laid before 1930. Don Valley Brick Works red and Cooksville Brick stock dominate the brick on these elevations. Indiana limestone, Owen Sound Ledgerock, and Eramosa appear on stone trim, sills, lintels, and accent work. The mortar was lime-based, mixed on site by the working masons of the day, with proportions that varied from yard to yard.
Restoration on these walls calls for matching the original chemistry: NHL5 hydraulic lime mortar, salvage brick from period-correct suppliers, hand-finished profile matching where decorative detail has eroded. Toronto Heritage Preservation Services and Parks Canada both cite National Park Service Brief 2 on the mortar physics. Documentation is part of every heritage scope.
For specific scope, see our brick masonry, stone masonry, brick restoration, tuckpointing, retaining walls, chimney repair, and stone cladding pages.
Frequently Asked Questions
What’s the difference between a mason and a masonry contractor?
A mason is the trade worker who lays brick or stone on mortar. A masonry contractor runs the project — site assessment, permits, scheduling, multiple masons on a crew, inspection coordination. Most working masons we know are both. Our crews are working masons; the contractor side is run directly.
Are masons licensed in Ontario?
Not in the same way as electrical or gas trades. There is no provincial license required to call yourself a mason. Reputable masonry companies belong to industry associations, document their work, and follow ASTM and CSA standards even without a license requirement.
How do I find a good mason in Toronto?
Ask for a project log with photographs in named neighbourhoods. Ask which ASTM mortar type they would use on your wall. Ask about heritage scope if your home is pre-1930. The answers separate working masons from generalists fast.
What does masonry work cost in the GTA?
Tuckpointing $15 to $40 per square foot. Brick replacement $25 to $50 per brick. New brick wall $40 to $75 per square foot. Stone cladding $40 to $200 per square foot depending on type. Chimney repair $1,500 to $4,000. Specific ranges live on each per-scope service page.
Do you do small residential repairs or only large projects?
Both. Single-brick replacements, single-sill repairs, hairline crack repointing, and small accent feature installs are part of weekly work. We prefer ongoing relationships over one-off large jobs only.
Can a mason work on heritage buildings?
Yes, when they understand heritage materials and methods. Pre-1930 walls need NHL5 hydraulic lime mortar (not Portland), salvage brick matching, and Heritage Preservation Services documentation in HCDs. A working heritage mason has documented past scope on similar buildings.