After a long silence, here is an old little hack that took place in Alameda, in the Mechanics I building. Here's what our source had to say:

This tool place around 2003, and was there for a year before being torn down. The wall had 2 layers. In the first part there were 2 people involved, and around 4-5 hours of work. The second put up a fight, that required 3 people to work for 6 hours, during the Super Arraial [an annual IST party]. This is due to the distinct quality of the materials used in each part.