It is very important to follow the manufacturer’s instructions when installing the outdoor composite decking materials. Thermal expansion is always something to be aware of when dealing with composite decking. In most climates, temperatures fluctuate enough to cause a problem with how the decking is spaced all year. Composite decking tends to grow and shrink across the length of the composite boards as it heats and cools. Proper spacing will allow some movement without buckling.

Some composite tongue and groove decking materials are designed to be installed with a hidden composite decking fastener. These clip systems generally are screwed into the composite decks frame across each joist and fit tightly into a cavity running down the side of the boards. 

We recommend using screws in the reverse thread when face-screwing composite decking to eliminate mushrooming. Mushrooming occurs when a standard bugle head screw pulls some composite material above the surface during installation.  it isn’t very attractive when resulting raised bump. You can also use a hammer to level the surface.

Hollow composite decking boards product will leave open ends that aren’t attractive and can collect dirt when cutting outdoor decking boards, leaves, etc. Most capped composite decking products sell end caps that can close the ends. Another method involves installing a racetrack or picture frame pattern perimeter to cover the open ends.