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.
Controlling composite deck boards seams
It is better to try to avoid seams on your deck surface when doing composite decking installation. Butt joints tend to separate and warp as the affordable composite decking material weathers. Depending on the size and shape of your deck design, this may be easy to accomplish without any effort, or you may have to make some adjustments. when that is over 20’ wide, applying to the deck diagonally can often reduce or eliminate the number of butt joints on composite decking designs. In some cases, you may decide that it is easier to use a division board to create one continuous seam across the deck surface. This technique is used to control the seam and make it appear to be a part of the design.
Double keel and double connector
Please pay attention to the end-to-end position when installing the composite wood decks.
Please use double keels here, so that the end of the floor can be supported with sufficient strength at this composite decking spacing to keep the board under uniform force and not to break or damage due to improper support.
In addition, please use a double connector, so that the possibility of the board moving due to stepping or normal expansion at this end will be avoided due to the doubling of the fastening effect of the connector.
Notice the blocking on the sides to support the border.
The field deck in this picture is 24' wide with an additional 6" picture frame border. In this case, we are staggering the butt joints every 4'. We added double 2x10 joists to support the seams. An alternative is to use a division board and create 2 decking fields.