Deck Failure, Repair, and Retrofit

25 07 2014

Bad ending to a BBQ!

As a Renovation contractor, I handle the demolition phase myself, allowing me to see the  mistakes that caused a particular failure and learn from them.  Decks are no exception, and are unique in that many homeowners install them as DIY projects because they seem simple and easy to accomplish on a weekend.  With decks, what the typical homeowner doesn’t know can injure or kill someone.

Common mistakes begin at the existing structure.  I see weak ledger-to-structure attachment, missing flashings, ledger attached over the the siding, weak or inadequate railing systems, and general lack of structural framing technique.  Because it’s a weekend project, it typically doesn’t get permitted or inspected, and the flaw becomes a ticking time bomb.  Factor in the height of a second or third story deck and you get my point.


Simpson’s Ledger-to-Structure Tension Connection Detail. Note the “Interior” work required.


View looking up at a ledger tension connection and tension connections for a guardrail post.


View looking down at tension connections for multiple guardrail posts in a corner.

In 2009 the International Code was updated to include deck construction standards to eliminate failures that ended in a fatality.  By code we have standard fastening dimensions, spacing, patterns, and tension details which make so much sense when you put them into practice.  The Simpson Strong-Tie company was instrumental in manufacturing connectors that make practical sense in applying the new code.

In nine out of ten decking projects I simply retrofit the existing deck by replacing any rotted wood, tightening it up, and tensioning it tight to the original structure.  This includes a lot of structural metal hardware, galvanized fasteners, and stainless steel screws.

Finished deck, PVC "Ipe" decking, Mahogany posts and rails, Stainless Steel cabling.

Finished deck, PVC “Ipe” decking, Mahogany posts and rails, Stainless Steel cabling.