Given the issues with owning decks, it is somewhat impressive that we insist on having them. I understand the fascination with them--have built plenty of them myself. We have been building them for as long as we have been building wood houses no doubt. We used to call them porches and they typically had a roof over them, they often had real foundations under them and many could even be enclosed in the winter and/or screened in the summer.
The whole notion of extended decks (that are sometimes more square feet than the house itself, with no roof) is a relatively new idea. They gained a whole lot of popularity with the advent of pressure treated lumber, which allowed them to last long enough to warrant the expense.
Aside from homeowner maintenance issues, the construction of decks is all too often the work of the weekend warrior or “professionals” that missed the class on deck construction because--well, how hard can it be?
A recent newer deck that I inspected is a case in point. It is almost understandable that older decks might have a variety of installation issues that make them unsafe. For new construction to have safety issues is almost arrogant. The building codes have become so prescriptive that even the weekend warrior should be able to handle the project safetly—assuming they can read, care and/or know where to find the information. A thing called “Google” has made the excuse of “ignorance” an impossible defense. What we have left is relegated to arrogance.
The intent of this post is not to list the many things that can go wrong with deck installations but to show how this particular deck performed under “inspection” and why it performed as it did.
When you look at this next picture, you can see how this walkway (about 5’ wide), that connects a huge deck on one side of the house to another huge deck on the opposite side of the house, is supported.
It is supported by diagonal 4x4’s that terminate on top of some buried 4x4’s against the foundation. What these buried 4x4’s rest on, could not be determined but they are inadequate as indicated by the amount of slope away from the house of the walkway.
There is considerable leverage at the outer edge of the walkway. This leverage is demonstrated in the following video, where my friend and fellow home inspector Don Hester obligingly jumps up and down at the outer edge. You may have to watch the 6 second video a couple of times to see what happens.
The ledger is actually flexing under the weight and pulling away the ledger, along with the siding, it is attached over.
This movement is consistent with inadequate attachment of the ledger and the two 2x6 outriggers that attach to the diagonal brace. The fact that these outriggers are undersized for all the joists and floor loads hanging on them only exacerbates the issue.
As in icebergs, this was just the tip in relation to the many safety concerns with this deck. It will need major modifications—hopefully by professionals other than the parties that built it originally.
Charles Buell, Real Estate Inspections in Seattle
* * * * * * * * * * * * * * * * * * * * * * * * *
WA State, Home Inspector Advisory Licensing Board