BTC Completes ANOTHER Fall Arrest Roof Anchor Installation
The 1120 North Lake Shore Drive Building is a 20-story residential building completed over 90 years ago. The
building features patinaed standing seam copper gable roofs, setback terraces, and a narrow low-slope roof
by original structural steel, hollow clay tile, and a topping slab. The low-slope roof is parallel to Elm
and a gabled attic on the east elevation is parallel to Lake Shore Drive, forming the building’s
In 2017, The 1120 Lake Shore Drive Building Corporation retained Building
Consultants, Inc. (BTC) to evaluate the feasibility of installing fall arrest roof anchors to safely
accommodate window washing and facade
access. BTC’s Project Manager, Mr. Josh
states that the project was complicated due to lack of
structural drawings, concealed structural steel framing members, and the steep-slope gable roof on the east
the 1925 building. This required a significant investigation to locate members suitable to support
fall arrest loads, including exploratory openings, ground penetrating radar (GPR), and steel coupon testing,
followed by a structural analysis.
BTC’s evaluation indicated that the existing low slope roof structure would be insufficient in
OSHA-prescribed loads for personal fall arrest equipment. As such, the roof structure was required to be
with new structural steel welded to existing steel framing members and embedded in the concrete roof slab.
fall arrest anchors were then attached to the new structural steel.
To address the unique layout of the east attic, BTC designed tieback anchors attached to existing attic floor
support steel and safety line guides penetrating through the gable roof (Photos 1 and 2). The safety line
consisted of stanchion-supported tube steel with operable insulated enclosures within the attic space.
For this project, BTC provided Evaluation, Design, Bidding Assistance, and Construction Phase services.
www.btc.expert for additional information about the
Project and BTC's