General feedback indicates that the most common occurrence of deck failure is with the substructure. This issue affects not only timber decking projects – wood substructures are often used with composite boarding too.
Despite clear guidance being readily available concerning the correct installation and maintenance of decks, the reality is that shortcuts are sometimes taken on the substructure (which is not usually visible post-installation). If property owners make little attempt to clear vegetation and/or debris which accumulates beneath a deck, this restricts air movement and traps water. In addition, it is common for deck joists to be set directly on or very close to the ground.