Do not install decking directly to a solid surface. Make sure there is adequate and unobstructed air flow under the deck to prevent excessive water absorption. Improve drainage or grade flat areas where standing water may gather. Allow a minimum of 6"" (15 cm) between the bottom of the deck substructure/joists and the ground. The deck design must allow unrestricted airflow under at least 50% of its perimeter to permit adequate ventilation.
Allow a minimum of 1/16"" gap between board ends for every 20°F of difference between installation temperature and the hottest temperature expected. Additional blocking may be needed for support. Allow 1/4"" distance between all decking material and any permanent structure or post. After all decking has been attached, snap a chalk line (white or yellow chalk recommended) flush with or up to 1-1/2"" out from the deck framing and trim with a circular saw. All wood and Composite decking products require proper ventilation and drainage in order to ensure its longevity. When using a minimum 2x6 joist standing on edge, with the suggested 1/4"" side gap, there should be a 2"" clear space between the bottom edge of the joists and grade to allow for proper ventilation. Adequate drainage is also needed to prevent water from pooling under the deck.
Joist Span 16"" on-center for residential perpendicular applications. Residential parquet patterns and diagonal or herringbone designs all require joist spacing 12"" on-center.
For ease of installation, we recommend using 2-1/2"" corrosion-resistant, composite wood deck screws. These screws help minimize the common “mushroom” effect that sometimes occurs when using standard fasteners. They can also reduce the amount of pre-drilling and countersinking. If using ordinary coarse thread deck screws, always pre-drill a pilot hole and countersink prior to driving screws. Screws should be driven flush with the decking surface. Do not over-tighten. Use two fasteners per deck board at each joist. For any decking where two boards meet end-to-end over a joist, add additional blocking. Always pre-drill a pilot hole and countersink at board ends when using either composite or wood screws. Be careful not to over-tighten screws near board ends.