How thick should a concrete garage floor be in Bathurst if I plan to park a heavy commercial trailer or skid steer on it occasionally?

For occasional heavy commercial equipment in Bathurst, you'll need a minimum 6-inch thick concrete slab, but 8 inches is the safer choice for true commercial trailers and skid steers. Standard 4-5 inch residential garage floors are designed for cars and light trucks — they'll crack under concentrated loads from heavy equipment outriggers, trailer tongue weights, or skid steer tracks.

Commercial Equipment Load Considerations

A loaded commercial trailer can impose point loads of 15,000-25,000 pounds through small contact areas like trailer legs or tongue wheels. Skid steers concentrate their entire weight (6,000-12,000 pounds) through narrow tracks or small tires, creating ground pressures that easily exceed what residential concrete can handle. The key is distributing these concentrated loads across a thicker, stronger slab.

For 6-inch thickness, use 32 MPa (4,500 PSI) air-entrained concrete with #15M rebar on 12-inch centers both ways, placed 3 inches from the bottom of the slab. This provides adequate strength for occasional heavy use — maybe once or twice per month. For 8-inch thickness, you can use 25-30 MPa concrete but still include the rebar grid. The extra thickness distributes loads better and provides more durability under repeated heavy loading.

Bathurst Climate Requirements

Bathurst's northern New Brunswick location means you're dealing with some of the province's harshest freeze-thaw conditions — potentially 160+ cycles per year with coastal salt air effects. Air-entrained concrete is absolutely mandatory for the slab surface. Even though this is an interior garage floor, moisture from snow melt, salt spray, and humidity will penetrate the concrete surface. The air entrainment (4-7% air content) gives freezing moisture room to expand without spalling the surface.

Your base preparation is critical in Bathurst's frost-prone soils. Remove any organic material and excavate to undisturbed soil or properly compact granular fill. Install 6-8 inches of compacted gravel base with a vapor barrier (6-mil poly) between the gravel and concrete to prevent moisture wicking from below. The slab should be isolated from the foundation walls with expansion joint material to allow for thermal movement.

Reinforcement and Control Joints

Heavy equipment creates dynamic loads that standard wire mesh can't handle. Use #15M rebar in a 12-inch grid pattern, supported on chairs at the proper height (3 inches from bottom for 6-inch slab, 4 inches from bottom for 8-inch slab). Install control joints every 12-15 feet maximum to control where shrinkage cracks occur — ideally aligned with any overhead door openings.

Consider adding fiber reinforcement (steel or synthetic) to the concrete mix for additional crack resistance. This costs an extra $30-50 per cubic yard but helps control plastic shrinkage cracking during curing and improves impact resistance under heavy equipment.

Professional Installation Recommended

An 8-inch commercial-grade garage floor requires 8-12 cubic yards of concrete that must be placed, screeded, and finished within a narrow time window. The reinforcement installation, proper consolidation around rebar, and achieving the correct surface finish for heavy equipment use requires professional experience. Mistakes in a heavy-duty slab are expensive to fix and compromise the floor's load-bearing capacity.

Find experienced concrete contractors familiar with commercial flooring requirements through the New Brunswick Construction Network — they'll understand the specific challenges of heavy equipment floors in Bathurst's climate conditions.