What is the best concrete cleaner for NB driveways?

The best concrete cleaner for a New Brunswick driveway depends on what you're cleaning — oil stains, rust, mould and algae, or general traffic grime each responds to different products. Using the wrong cleaner wastes time and money, and some products can actually damage concrete or compromise a sealer if applied incorrectly.

For oil and grease stains — the most common driveway problem in NB — a commercial degreaser or concrete-specific oil stain remover is your best option. Products containing sodium lauryl sulfate or citrus-based solvents work well on fresh to moderately aged stains. For older, set-in oil stains, apply a poultice made from powdered laundry detergent or oil-dry absorbent mixed with hot water, scrub with a stiff brush, let it sit for 30 minutes, then rinse. For heavily saturated stains, a commercial product like Concrete Cleaner & Degreaser (available at NB building supply stores) followed by a pressure wash at 1,500-2,500 PSI is effective.

For efflorescence (the white powdery mineral deposits that appear on driveways and retaining walls, especially in spring) — a diluted muriatic acid solution (1 part acid to 10 parts water) applied with a plastic brush and rinsed thoroughly works well. Always neutralize with a baking soda and water rinse before the acid dries, and wear gloves, eye protection, and old clothing. This is standard practice for NB driveways where spring melt water carries mineral salts to the surface.

For mould, algae, and dark staining — common in shaded NB driveways, especially in river valley communities like Fredericton and Miramichi where moisture lingers — oxygen bleach (sodium percarbonate) mixed with warm water is effective and less damaging to surrounding vegetation than chlorine bleach. Apply, let dwell for 10-15 minutes, and pressure wash off.

For general cleaning and pre-sealing prep — a concrete and masonry cleaner followed by a thorough pressure wash is the standard approach. If you're preparing to apply a sealer (which you should be doing every 2-3 years in NB), the surface must be completely clean and dry before sealer goes down. Any oil, dirt, or residue trapped under the sealer will cause adhesion failure and peeling.

After cleaning, always inspect the surface for cracks and spalling before resealing. Small cracks under 1/4 inch can be filled with a concrete crack filler before the sealer is applied. NB driveways benefit most from a penetrating silane/siloxane sealer applied after cleaning, as it provides the best freeze-thaw and salt protection for the Maritime climate.