HONG KONG — Eric Wu, a 37-year-old construction worker, has spent his entire adult life building and climbing bamboo scaffolding as high as 50 floors above the ground.

But on Monday morning, he used his talents to pursue a different goal — lashing together two-inch-thick bamboo poles in an elaborate lattice that he designed to protect an encampment of pro-democracy student protesters here. The lattice was a yard high, about 20 feet wide and 30 feet deep, and blocked a road near the Hong Kong Police Headquarters.

He paused occasionally from expertly lashing together 12-foot-long poles with strips of black plastic to give instructions to student protesters, who were more clumsily trying to tie poles together using long lengths of clear plastic wrapping. He talked about how he thought democracy would create a better Hong Kong, but also gave an economic reason for his presence at the demonstration: “Times are tough; there are no jobs in construction.”

Protesters added more bamboo-pole lattices to their barricades through Monday evening, and were sawing off the ends of some of the longer poles to give them long, sharp points. If the protesters wield the poles as pikes, they could make it considerably more dangerous for police or others to try to disperse them.