Yes, it is watertight, not just water-resistant. The pressure-lock fulcrum joint system channels water through the boards and into an integral gutter below, keeping the surface dry without pooling. The aluminum boards don’t absorb moisture, so there is nothing for the freeze-thaw cycle to work against. No caulk, no rubber gasket, no material that degrades over time.

Less than you would expect. The boards were independently tested in direct sunlight. On a hot Ontario afternoon, GrandVista aluminum runs significantly cooler than composite decking of comparable colour. The textured surface also helps compared to smooth aluminum, which would hold more heat. In a darker colour like Earthstone or Black, the boards will be warmer than White or Sand, but within a comfortable range for bare feet.

Wood decks in this climate rot, splinter, and need refinishing on a schedule that Ontario’s climate accelerates. Composites handle moisture better than wood but eventually fade and can go brittle in the cold. Aluminum does none of those things. It will not warp, twist, mildew, or splinter regardless of how many freeze-thaw cycles your property goes through. The trade-off is upfront cost. Aluminum costs more. For local homeowners who want to build it once and genuinely never maintain it, that trade-off makes sense.