7 On Your Side: How to spot dry rot dangers

SAN FRANCISCO (KGO) -- While the cause of the balcony collapse in Berkeley won't likely be known for a while, much attention has been given to the possibility of dry rot. There are some obvious warning signs of it, so 7 On Your Side looked into what those signs are so you can be aware.

Dry rot has been blamed for several deck collapses in San Francisco. The good news is such accidents are avoidable.

Tom Hui is director of the San Francisco Building Inspection Department. He showed us pictures from a deck collapse in the city back in January where a guard rail gave way during a party and left three guests injured when they took a fall 20 feet onto concrete. Investigators concluded dry rot was to blame.

"Look at the deck, here is a little bit of the dry rot, and then this guard rail post is dry rot here," Hui said.

Dry rot was also blamed for a fatal deck collapse in 1996 in San Francisco. Investigators also determined dry rot caused another deck collapse two years later, injuring several people.

The coastal weather conditions make dry rot a problem throughout the Bay Area. Hui says there's something you can do to protect yourself. He said, "Have a screw driver punch through it. Then you can see better."

If you poke the wood and it crumbles, it likely has dry rot.

The Berkeley accident and the three incidents mentioned in this report all happened at parties. Hui suggests limiting the number of people on most residential decks or balconies to four, just to be safe.

San Francisco requires balconies and decks to be inspected every five years. It's one of the toughest requirements in the state. We contacted the city of Berkeley to ask about any inspection requirements there and have not heard back.