Concrete Garage Floors & Workshop Slabs — Build a Floor That Lasts

Your garage or workshop floor takes constant abuse — vehicle weight, tools, chemicals, and work boots. A poorly built slab cracks, dusts, and stains within a few years. Here's how to get a concrete garage floor that lasts for decades.

Get the Thickness Right

For a standard residential garage, a slab of 100–125mm with steel reinforcement (SL72 mesh or fibre) is the minimum. If you park a heavy 4WD, a trailer, or a boat, go to 150mm. The sub-base underneath matters just as much — it must be compacted properly or the slab will crack under load.

Plain vs Finished Garage Floors

• Plain trowel finish — smooth and easy to sweep, but slippery when wet and stains easily
• Broom finish — added grip, good for a workshop floor
• Epoxy coating — the premium option: hard-wearing, chemical-resistant, looks fantastic, and easy to clean (see our separate epoxy guide)
• Integral colour — a light grey or coloured surface hides dust and looks cleaner

Epoxy — Worth the Investment?

Epoxy is the best upgrade for a garage floor. It seals the concrete (no dusting), resists oil and chemical spills, and can last 10–15 years with proper prep. Metallic epoxy gives a stunning showroom look, while solid epoxy is more budget-friendly. If you use your garage as a workshop, epoxy is almost essential.

What Does a Garage Slab Cost?

For a standard double garage (~40m²):

• Plain reinforced slab: $125–$150/m²
• With broom/textured finish: similar range
• Epoxy coating (add-on): $50–$120/m² depending on type
• Typical double-garage total: $5,000–$9,000 installed

Wet Area & Drainage

If your garage doubles as a workshop, plan the fall (slope) toward a floor drain or the door so spills and wash-down water drain away. This protects your slab and stops water pooling under vehicles or shelving.

Repairing an Old, Dusty or Cracked Floor

You don't always have to dig up an old garage slab. If the existing concrete is sound but dusting, cracked, or unsightly, a concrete overlay or epoxy coating can transform it — faster and far cheaper than replacement. We assess the base first to make sure the overlay will bond and last.