What is #1 Reason Decks Fail?

Often times a new deck doesn’t last as long as it should due to failure of setting up these simple protections. This video quickly explains the number one reason decks fail: not using double metal flashing around the ledger board, deck and undersill trim.

Double metal is the proper installation, and without it you can be looking at serious rain damage to your decking, especially in the Pacific Northwest. In addition there are other structural damages that can be expected if your deck installation isn’t done properly.

There should be deck metal that’s used underneath the board, but also on top. Double metal flashing is a proper installation. You should have a piece of L metal that will cut down over the top of the board, and that double flashing is what makes sure when you get wind driven rain you’re not going to have an issue with ledgers. One of the main reasons that decks fail is because of the ledger board.

What is the most common cause of deck collapse?

The ledger board is important, not just to protect the home and deck from water damage, causing rot. But also you can avoid total deck collapse. This is most commonly caused by the deck “pulling away” from a house.

This type of deck fail typically involved the ledger board being improperly attached to the house. Other structural failures in decks could also involve weakening of support posts and deck joists.