The installation of the scaffolding and shoring of Unity Temple's south roof slab is complete. Even though the staff was accidentally trapped downstairs by a rogue crossbar, it was a very interesting process to watch. It is also a significant milestone. Now that the roof is supported, demolition of select segments can begin.
The entrance hall is now a thicket of shoring posts. They have been "shrouded" in white muslin so people won't bump into the posts and hurt themselves, but here's a look at the bare bones. If you look carefully, you can see how Safway used steel I-beams to bridge the loads over the old heating tunnels.
On Thursday morning, I climbed up onto the roof (thank you, Alex, Mark, and C.P.) to see the shoring up close and get a look at the temporary roof that Zera was building. From below, you can get a sense of the strength of the shoring and the imposing load it supports:
Up on the south slab, Henry and his crew from Zera Construction were busy building the temporary roof structure that will keep the weather out when the roof is demolished. It stretches from the parapet wall (on the right in the photo) about 10'-8" to wear the roof cantilevers beyond the columns (on the left). (All the cantilevered eaves were restored in 2001, with the $1,000,000 from the State of Illinois. They are in excellent condition and are not part of this project.)
While C.P. and the Safway engineer reviewed the scaffolding and shoring, Zera continued to remove plaster from the underside of the roof slab. They also submitted two concrete mix designs to C.P. for approval.
Speaking of concrete, in the beginning of the summer C.P. invited us to observe when the first test batch was "whipped up" at CTLGroup's offices and laboratories in Skokie. CTLGroup used the same mixer it's used for decades. It was hard not to draw comparisons to a bakery:
Next: a trip to the glass restorer's studio.