Should I use sealed or unsealed natural stone in Vancouver?

For Metro Vancouver's wet climate, sealed natural stone is strongly recommended for most installations. The region's 1,200mm+ annual rainfall and persistent 60-80% humidity create ideal conditions for staining, moss growth, and water damage that sealing helps prevent.

Why Sealing Matters in Vancouver's Climate

Natural stone is porous and absorbs water, oils, and organic matter. In Metro Vancouver's marine climate, unsealed stone becomes a magnet for moss, algae, and lichen growth — especially on north-facing installations or areas shaded by trees. The constant moisture also allows tannins from falling leaves to penetrate and stain the stone permanently. Sealed stone repels water and contaminants, making cleaning easier and preventing most permanent staining.

Performance Benefits of Sealing

A quality penetrating sealer (like those from SureCrete, Prosoco, or Dry-Treat) soaks into the stone's pores and creates a hydrophobic barrier without changing the stone's natural appearance. This prevents water absorption that can lead to freeze-thaw damage during Vancouver's occasional winter freezes, reduces efflorescence (white mineral deposits), and makes moss removal much easier. Sealed flagstone, slate, or granite maintains its original colour longer and resists the grey, weathered appearance that unsealed stone develops in this climate.

When to Consider Unsealed Stone

Some homeowners prefer the natural weathering process, especially for rustic or cottage-style landscapes. Unsealed stone develops a patina over time that can be attractive. Dense stones like granite and basalt (common BC materials) are naturally more resistant to water absorption and may perform adequately unsealed in well-drained locations. However, even dense stone benefits from sealing in high-traffic areas like walkways and patios.

Sealing Requirements and Maintenance

Natural stone should be sealed 30-60 days after installation to allow any construction moisture to evaporate. Reapply sealer every 3-5 years in Vancouver's climate, or when water no longer beads on the surface. Clean the stone thoroughly before sealing — pressure washing followed by a stone-specific cleaner removes any efflorescence or organic growth. Apply sealer during dry weather with at least 24 hours of no rain forecasted.

Professional installation ensures proper sealing timing and technique. Stone contractors understand which sealers work best with specific stone types and can apply them correctly for maximum longevity in Metro Vancouver's challenging climate.