Sealing a driveway extends the life of the surface by reducing porosity and protecting against staining, water damage, freeze-thaw erosion, and biological growth. The type of sealer and the application method depend on the driveway material.

When to Seal

New concrete driveways should be allowed to cure for at least 28 days before sealing. New block paving should be sealed after the kiln-dried sand jointing has been allowed to settle and compact, typically two to four weeks after installation. Existing surfaces should be thoroughly cleaned and allowed to dry completely before sealing; applying sealer to a dirty or damp surface traps contamination beneath the sealer and produces a poor result. Dry, mild weather is the ideal sealing condition; do not seal if rain is forecast within four to six hours or if temperatures are below five degrees Celsius.

Concrete Driveways

Concrete is a porous material that absorbs water, oil, and contaminants. A penetrating or impregnating sealer based on silane, siloxane, or siliconate chemistry penetrates the surface and lines the pores from within without forming a visible surface film. These products are breathable, meaning moisture within the concrete can still evaporate, and are invisible once applied. They repel water and oil and slow biological growth. Apply with a brush, roller, or low-pressure sprayer, ensuring the sealer is absorbed and not left pooling on the surface.

Block Paving

Block paving sealers are available in two main types: wet look sealers that give the paving a slightly darkened, damp appearance, and natural sealers that are invisible after application. Both types protect against staining and stabilise the kiln-dried sand joints, reducing weed germination and ant activity in the joints. Apply the sealer with a brush or roller in long, even strokes, overlapping each pass. Two thin coats provide better results than one thick coat. The second coat can be applied once the first is touch dry, typically one to two hours.

Tarmac Driveways

Tarmac driveways can be treated with a bitumen-based rejuvenation sealer that restores the colour of weathered tarmac and seals the surface against water penetration and further oxidation. Apply with a brush or roller and allow to cure for at least four to six hours before vehicle use. Applying sealer to tarmac every three to five years significantly extends the life of the surface and maintains its appearance.

Summary

Sealing a driveway protects against water damage, staining, and biological growth. Clean and dry the surface thoroughly before applying any sealer. Use penetrating sealers for concrete, wet-look or natural sealers for block paving, and bitumen rejuvenation sealers for tarmac. Apply in dry conditions above five degrees Celsius. Test in a small area before full application, particularly for wet-look products.