KAYU Hardwood Decking Installation Essentials

Storage and Handling

Kayu Decking Installation Essentials left facing deck with lake in background

  • Before installation and finishing, keep your KAYU® hardwood deck boards clean, dry and out of direct sunlight.
  • Do not cut Metal anywhere near KAYU®-Hardwood during the installation process, avoiding MPCC (Metallic Particle Corrosion Contamination).


  • Prior to installation, seal decking with a high quality penetrating oil sealer on all four sides. Sealing only one side can create uneven moisture flow which increases the likelihood of cupping.
  • A periodic cleaning and a light coat of finish will be necessary, In order to maintain the original color of the deck. The rate at which maintenance is needed depends largely on the degree of exposure to direct sunlight, the climatic conditions, preference of deck color and the frequency at which any preservative treatments are applied.
  • Similar to other exterior wood products, KAYU® Hardwoods will gradually fade to a soft silver-gray patina color over time. If this is preferred, leave all four sides unfinished and allow to weather naturally.

Kayu table and illustration showing Maximum Allowable Decking Spans

Ventilation and Air Flow

  • Check and follow your local building codes.
  • Allow adequate ventilation for proper air flow to reduce the potential for cupping and surface checking (see diagram).
  • For maximum long term stability, install the deck with a minimum ground clearance of 18″, with at least two sides of the deck open. It is necessary to have at least 50% unrestricted airflow at all times.
  • Create a slope for drainage posing no chance of standing water.
  • If a minimum ground clearance of 18″ is not obtainable, we recommend installing 5/4 X 4 decking.


  • KAYU® decking is kiln dried for consistency. Unlike air dried boards, shrinkage is very limited. However, excessive moisture may cause the boards to expand slightly.
  • Install 6″ (5-1⁄2″ net) decking with a minimum gap of 1⁄4″ between each deck board. 4″ (3-1⁄2″ net) decking should have a minimum gap of 3/16″ between each board. In addition, allow 1⁄4″ from any structures such as foundations or rail posts.
  • In more demanding applications, such as boat docks, decks built closer to the ground and decks with less airflow, a minimum gap of 5/16″ for 6″ decking and a minimum of 1⁄4″ for 4″ is necessary.
  • KAYU® decking does not shrink or expand end to end, therefore neatly trim ends and butt together.


  • Pre-drill pilot holes and countersink for all screws, using high quality #10 (or greater) stainless steel screws, with a minimum screw penetration into joist of 1-1⁄2”.
  • Face screwing or edge screwing are the most effective methods of installation. It is important that every joist, is fasten through the face of the board. Do not use hidden clip fasteners or nails!


  • Safety should be one of your main concerns when installing decking and/or flooring. We recommend wearing protective eyewear, dust masks and gloves during installation. When using a saw, always cut away from your body. Check with your local department of Building and Safety before you start a project and/or have safety concerns.


KAYU® hardwood decking products are carefully selected and inspected to ensure the finest quality. However, all natural wood is subject to expansion and contraction as the moisture in the environment surrounding the wood changes. Shrinkage, expansion, checking and other movement are normal occurrences in all hardwood decking. Natural wood products are subject to variances in color, grain, density and performance.