Concrete Accessories Every Job Site Needs

Everyone remembers to order the concrete. It’s the accessories that get forgotten — and one missing item can hold up an entire pour. If you’ve ever sent a guy to run and grab rebar chairs at 6:30 AM because nobody checked the supply list, you know exactly what I’m talking about.

Here’s the full list of concrete accessories that should be on every job site before the truck arrives.

Reinforcement

Rebar

The backbone of structural concrete. In Ontario residential and commercial work, the most commonly used sizes are:

• 10M (11.3 mm): Slab-on-grade reinforcement, temperature steel, light structural
• 15M (16 mm): Foundation walls, footings, structural slabs — the most common rebar size on GTA residential sites
• 20M (19.5 mm): Heavy structural — commercial foundations, parking garages, engineered beams
• 25M (25.2 mm): Major structural elements — not common in residential

Rebar is sold by length (typically 6 m / 20 ft standard lengths) and priced by weight (per tonne) or per piece for smaller quantities.

What to check: Make sure the rebar matches the engineer’s drawing — correct size, correct spacing, correct lap splice length. In Ontario, standard lap splice for 15M bar is 600 mm (roughly 40 bar diameters). Don’t guess on splices — it’s an inspection failure.

Wire Mesh

Welded wire mesh (WWF) is the alternative to individual rebar for slab reinforcement. Standard residential mesh in Ontario is 152 × 152 MW18.7/MW18.7 (6” × 6” spacing, 3 gauge wire).

Mesh is faster to install than individual rebar for large slabs — driveways, garage floors, basement slabs. But it needs to be properly lapped (one full square overlap, tied with wire) and supported on chairs so it sits in the middle or lower third of the slab, not on the ground.

Mesh sitting on the ground does nothing. It’s decoration. Support it properly or don’t bother with it.

Fibre Reinforcement

Polypropylene or steel fibres mixed directly into the concrete. Poly fibres (at standard dosage rates) control plastic shrinkage cracking — the hairline cracks that appear in the first 24 hours. Steel fibres provide structural reinforcement and are sometimes used as a mesh replacement on certain slab applications.

Fibres are not a substitute for rebar in structural applications. They’re an addition, not a replacement.

Form Accessories

Form Oil / Release Agent

Applied to the inside face of forms before pouring. It prevents the concrete from bonding to the form, which means cleaner strips and reusable form material.

Two types:

• Standard form oil: Petroleum-based, cheap, effective. Standard for most residential work.
• Biodegradable release agent: Required on some municipal and commercial specs, particularly near waterways.

Apply a thin, even coat. Too much oil causes surface discolouration on the concrete. Too little and the forms stick, tearing the concrete surface when you strip.

Snap Ties

Metal ties that hold the two sides of a wall form together at the correct spacing. Standard residential foundation walls use snap ties at 24” horizontal and 12–16” vertical spacing. Each snap tie has a small cone (she-bolt cone or snap-off cone) that breaks flush with the concrete surface when the forms are stripped.

After stripping, the snap tie holes need to be patched with non-shrink grout or a cementitious repair mortar — especially on below-grade walls where water can track through the holes.

Form Stakes and Braces

For slab edge forms, you need wood or metal stakes driven into the ground to hold the forms in position. For wall forms, diagonal braces (walers and strongbacks) prevent blowout during the pour.

Underbrace your wall forms and find out during the pour — that’s a lesson nobody needs to learn twice. The lateral pressure from wet concrete at 2.4 metres of head is over 50 kN/m². The forms will move if they’re not locked down.

Support and Spacing

Rebar Chairs (Supports)

Small plastic or metal supports that hold rebar and mesh at the correct height within the form. Types:

• Slab bolsters: Continuous wire supports that hold mesh or rebar at a consistent height across a slab. Standard heights: 38 mm (1.5”), 50 mm (2”), 75 mm (3”).
• Individual chairs: Plastic snap-on chairs for individual bars. Used in wall forms and footings.
• High chairs: Taller supports for upper layers of reinforcement in thick slabs.

The correct cover (distance from rebar to the nearest concrete surface) depends on the exposure condition:

• Interior slab, not exposed to weather: 20 mm cover
• Exterior, exposed to weather but not soil: 40 mm cover
• In contact with soil (footings, foundation walls): 75 mm cover

Get the cover wrong and either the rebar corrodes (too little cover) or it doesn’t contribute structurally (too much cover, sitting too deep in the section).

Dowel Sleeves and Expansion Joint Filler

For joints between a new pour and an existing structure (like a new driveway meeting an existing garage apron), you need:

• Dowels: Short pieces of rebar connecting the new pour to the existing concrete for load transfer
• Expansion joint filler: Compressible foam board (typically 10 mm asphalt-impregnated fibreboard) placed between the two pours to allow for thermal expansion

Skip the expansion joint on a GTA driveway and watch the concrete crack where it meets the garage. Ontario’s temperature swings — from -25°C in January to +35°C in July — mean thermal movement is a fact of life for any exterior slab.

Finishing and Curing

Hand Tools

Every finishing crew needs:

• Bull float / darby: For initial levelling after the screed
• Magnesium float: For opening the surface and preparing for trowelling
• Steel trowel: For final hard trowelling (interior slabs, garage floors)
• Edger: For rounding slab edges — reduces chipping and gives a clean look
• Groover (jointing tool): For cutting control joints. In Ontario, control joints should be placed at a maximum of 24–30 times the slab thickness (e.g., every 3–3.6 m for a 125 mm slab)
• Broom: For broom finish on exterior slabs — slip resistance is critical in Ontario winters

Curing Compound

Concrete needs moisture to cure properly. In the GTA, summer conditions — hot sun, low humidity, wind — can pull moisture from a fresh slab faster than the cement can hydrate. The result is surface cracking, dusting, and reduced strength.

Curing options:

• Spray-on curing compound: Most common. Applied immediately after finishing. Creates a moisture-retaining film on the surface. Standard for driveways, sidewalks, and commercial slabs.
• Wet curing (water or wet burlap): Labour-intensive but effective. Sometimes required on specification jobs.
• Plastic sheeting: Covers the slab to trap moisture. Can cause discolouration if wrinkled — lay it flat.

In cold weather (below 10°C), you may also need insulated blankets to maintain curing temperature. Concrete that freezes before reaching 3.5 MPa (roughly 24 hours of normal curing) is permanently damaged.

Sealers

Applied after curing (typically 28 days) to protect the surface from salt, freeze-thaw, staining, and wear. Particularly important for driveways and sidewalks in the GTA where road salt exposure is heavy from November through March.

Types:

• Penetrating sealer (silane/siloxane): Soaks into the concrete, doesn’t change the appearance. Best for driveways.
• Film-forming sealer (acrylic): Sits on the surface, adds a slight sheen. Common for decorative and stamped concrete.

The Pre-Pour Checklist

Before the ready-mix truck arrives, confirm you have:

• Correct rebar size and quantity (per drawing)
• Chairs and bolsters at correct heights
• Wire ties for securing rebar intersections
• Form oil applied to all form surfaces
• Snap ties installed at correct spacing (walls)
• Control joint layout marked on forms
• Expansion joint filler placed at construction joints
• Finishing tools on site and clean
• Curing compound ready to apply
• Test cylinder moulds if required by spec

One missing item doesn’t just cost you the price of the item — it costs you the crew’s time while someone runs to pick it up.

Stock Up Before the Pour

We carry the full range of concrete accessories at our supplies division — rebar, mesh, chairs, form oil, curing compound, sealers, and finishing tools. Available for pickup at our Mississauga (3330 Ridgeway Dr, Unit 7), Brampton (2084 Steeles Ave E, Unit 1), and Pickering (1020 Brock Rd, Unit 5) yards.

Need it delivered? Call 647-926-2597 or request a quote.