Up, up, and away

My son, bless his heart, warns me to exercise caution on my lunchtime walks: SF Transit Center park — open barely a month and path already falling apart

already the visitor walkway that encircles the rooftop park is crumbling.

“No one is happy about it,” Transbay center spokeswoman Christine Falvey said.

Dozens of spots along the half-mile path have become the walking equivalent of potholes.

Okay, I don't know if that really counts as "falling apart", but hey, headline writers, don't ya know.

The walkway — which affords visitors panoramic views of the surrounding city streets as well as access to the various attractions and botanical displays at the 5.4-acre park — is made of decomposed granite rather than asphalt.

And while permeable, decomposed granite pathways have been used successfully in parks around the country, the mix here has failed to hold up even under normal foot traffic.

Here's a good resource for learning about permeable decomposed granite: Using Decomposed Granite as a Garden Paver.

Whenever gardeners talk about "decomposition", I usually think first of fertilizer, not of pathways. Gotta expand my horizons...

Meanwhile,

A long-term fix has yet to be worked out.

“They don’t know what the problem is right now,” Falvey said.

The good news is that the walkway is under warranty.

Wait, what?

The walkway is under warranty?

Wow, there's a LOT I don't know about building multi-billion dollar downtown transit centers.

I'll try to find time to go take a spin around the pathway sometime in the next few days, and I'll let you know about my hands-on inspection...