The panels, valued at $1,000 each, were taken sometime during the early morning hours, Officer Nick Belliveau said.
The manager of the store, located at 660 Gravenstein Highway North, noticed a folding ladder outside the building when he arrived at work at about 7:30 a.m. Saturday, Belliveau said.
Police tried to lift fingerprints from the ladder but found none.
Investigators believe more than one person is responsible for stealing the 2-by-4-foot panels, Belliveau said.
The hardware store contacted the contractor that installed the panels to get serial numbers and other identifying information, Belliveau said.
Anyone with information is asked to call Sebastopol police at (707) 829-4400.