Should I use rebar or wire mesh in my NB concrete driveway?

For a residential concrete driveway in New Brunswick, welded wire mesh (6x6 W2.9/W2.9 or W1.4/W1.4) properly placed at mid-slab depth is the standard choice, while rebar is preferred for heavier-use driveways and areas subject to significant frost heave. Both work; the key is that reinforcement must be at the correct height in the slab — not lying on the ground.

Why reinforcement matters in NB driveways: Concrete slabs crack — this is not a design flaw, it is an expected behaviour of concrete under thermal expansion, contraction, and structural loads. Reinforcement does not prevent cracking (control joints do that by directing cracks to predetermined locations), but it holds the slab together after cracking so pieces do not separate, shift, or become trip hazards. In NB, where frost heave can push one section of slab up relative to another, reinforcement that bridges a crack prevents the classic dangerous lip that develops between unsupported panels.

Wire mesh is the most common residential driveway reinforcement in NB. Standard 6x6 W2.9/W2.9 welded wire mesh sheets (4x8 feet, $4-$7 per sheet) are economical, fast to place, and adequate for passenger vehicle loads on a 5-inch slab with a good granular base. They must be placed on wire chairs or concrete dobies that hold the mesh at 2-3 inches above the bottom of the slab — placing mesh on the ground and pulling it up during the pour is a common mistake that results in mesh sitting near the bottom where it provides little benefit in tension.

Rebar (#10M at 12-18 inch centres both ways) provides more robust reinforcement and is preferred for NB driveways that will see heavy vehicles (pickup trucks, RVs, delivery vans), driveways with challenging soil conditions or areas prone to frost heave, and wider slabs where long spans between control joints are unavoidable. Rebar adds cost — #10M rebar at $1.50-$2.50 per linear foot plus labour to tie and support it — but the extra strength is worthwhile for the situations noted above.

Fibres as a supplement: Polypropylene fibres added to the concrete mix are increasingly standard for NB driveways and are an excellent complement to either wire mesh or rebar. They control plastic shrinkage cracking during the critical finishing phase and improve the overall durability of the concrete matrix. Fibres do not replace structural reinforcement.

Bottom line: For a typical NB residential driveway, properly elevated wire mesh plus polypropylene fibres in the mix is an excellent specification. If you have heavy vehicles or know your site has frost heave history, step up to rebar. Either way, make sure your contractor places the reinforcement on chairs — not on the ground.