No Stacking The Deck
Synthetic wood manufacturers have requirements on the size of the gaps required between their decking boards. We have seen some decks where the synthetic lumber was spaced so tightly that water ponded and ice was formed on the deck surface. Manufacturers offer very long warranties (up to 25-year) but they will not honor the warranty if the gaps are too small and a future problem can be attributed to improper spacing of the boards. Check with the manufacturer before you start to install synthetic decking for the side to side as well as end gaps that are required.