We home inspectors see this all the time - decks - not attached correctly, not supported correcly - dangerous.
These photos are all from the same deck! And it has been there a while.
Example number one.
The outside joist.
The joists of the deck are erratically spaced, some 22" and some 24".
They rest on an exterior beam with a small cantilever.
Noticing how things are pulling apart? The first outside joist was merely nailed to the deck joists. And the guardrail is bolted to a deck joist! It got loose, so as a repair they nailed another outside joist to the first! See how it is loosening too?
Where do people congregate when they go out onto the deck? The outside guardrail! DANGEROUS.
Example number two.
The ledger beam is the beam that is attached to the house.
There are specific ways to attach it.
Decks don't collapse downward. Typically they pull away from the house. So the attachment to the house is every bit as important as the columns supporting it.
Look at how the exterior deck joist is attached to the ledger beam - nails.
They are loosening.
Also, notice how the guardrail is attached to the joist. It is loosening just as the joist is.
The ledger beam is attached to the house with what appears to be a through bolt.
But not enough bolts are present and ideally the bolts are in a V fashion, high and low on the beam.
What you can't tell from either of these photos is that the ledger beam has come off the house over 1" at the top.
It is pulling away!
Example number three.
Finally, two of the deck joists, spread too far apart, are attached to the chimney box as support.
THIS IS ENTIRELY INCORRECT.
The chimney box is not a structural component of the house.
It should be bypassed with a double joist in front, and a double joist to each side.
Any inteiror joists should be strapped to the double bypassing joist.
Perhaps you can see how this interesting arrangement is pressing on the corner of the chimney, collapsing it somewhat!
And the other "joist" is nailed to the corner of the chimney! This is scary all around.
When you walk on the deck it sways somewhat, wobbles somewhat, and these folks want to sell it to someone else.
My recommendation: decks are one of the things that almost always stand out in some way during a home inspection. Particularly when unprofessional installation, or repairs, has taken place. Homeowners should not put on a deck after watching a show on TV. They will not get enough information! And a TV show does not guarantee one's expertise in carpentry.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560