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LTC 081-2007 Historic City Hall Renovation Project lD MIAMI BEACH RECEIVED 7001 APR - 5 AH ,10: 39 CITY CLERK'S OfF ICE OFFICE OF THE CITY MANAGER NO. LTC # 081-2007 LETTER TO COMMISSION FROM: Mayor David Dermer and Members of the City Commission Jorge M. Gonzalez, City Manager ~ or ~ April 4, 2007 U TO: DATE: SUBJECT: Historic City Hall Renovation Project The purpose of this LTC is to inform you about the status of the undergoing repairs and renovations to the Historic City Hall Building. On July 12, 2006, the Mayor and Members of the City Commission ratified Resolution No. 2006- 26274, approving the Property Management Director's contract to National Concrete Preservation, Inc., in the total amount of $1,911,095, to provide for the removal of all the Historic City Hall exterior stucco surfaces and replacement with fiber reinforced stucco; the removal of all windows and replacement with hurricane impact resistant windows and frames; and the repair or replacement of all damaged exterior decorative moldings, cornices, and balusters. Many serious structural deficiencies were revealed during the initial removal of the exterior stucco. These deficiencies included concrete loss, reinforcement corrosion including structural steel beams and columns, brick wall damage, and window anchoring systems that were missing. The Property Management Director contacted BEA International, Inc., (Engineer of Record) to determine the structural damages, to the extent limited by the accessibility of the damaged locations at the time of the inspection. The engineers also based their structural findings on their observations of a typical window and frame with the exterior stucco removed. The engineer was also requested to develop a structural repair plan based on his observations and findings. The structural plans developed by the engineer provided repair methods for the building's structural columns and beams for up to a 50% replacement requirement in which the initial structural change order increase was based. The Mayor and City Commission also approved the appropriation of an additional $1,900,000 from the Capital Reserve account for project costs and contingencies and approved the ratification of the Property Management Director's change order to National Concrete Preservation, Inc., in the amount of $1,759,504, to provide for the at the time known structural repair needs at the Historic City Hall Building. As work progressed, and windows and interior surfaces were removed, the extent of the unforeseen structural damages increased significantly. This was especially true on the base two floors of the building and the ninth floor that houses Police communications equipment and mechanical equipment rooms. The two base floors and the ninth floor, unlike the tower that utilized steel "I" beams in the construction method, were built using reinforced concrete columns and beams. When exposed, these structural elements were found to be well beyond repair due to severe spalling and critical loss of the reinforcing steel within the concrete. The beams and columns and the terracotta bricks that made up the exterior walls on these floors required 100% replacement. The requirement of this work included the need to bring in heavy shoring including temporary steel beams. These beams and heavy shoring are necessary to support the floors and roofs of the affected floors while the exterior walls sections were being completely replaced. Another significant unforeseen structural problems found in the building was with the existing windows. The windows in the tower section were attached to metal studs on the inside of the building which are not allowed by code. Because of the attachment method requirements of impact resistant windows, concrete "tie" columns are required to be installed to support the new hurricane impact resistant window frames. Additionally, the existing windows sizes were beyond the dimensions previously approved by Miami-Dade County product approvals. To overcome this problem, the Property Management Director hired a structural engineer that specializes in window construction to develop design specifications and the wind load calculations required to meet Miami- Dade product approvals. This process has been completed and the windows have been approved by the Building Department's Structural Engineer and recently (March 5th) by Historic Preservation for historic appropriateness for the building. The windows were ordered on the day the approvals were obtained. To meet the requirements of the building code and historic preservation that any structural deficiency found with the Historic City Hall Building must be repaired in a manner consistent with the original historic design of the building, the Administration will be requesting an appropriation offunds and a change order increase in the amount of $1 ,300,000 for the additional structural repair work and the addition of window "tie" reinforced concrete columns that are required on the project. The structural repair work on the project is approximately 85% complete. Other elements on the project such as replacement of the HV AC air handling systems are approximately 95% complete. This work required creating large openings in the exterior walls of the building just to get the equipment into the air handling rooms. The complete renovation of the two elevators and the antique elevator equipment in the building is currently out to bid and the Property Management Director expects the work to be under contract in April. The Property Management Director expects to start receiving windows within the next three weeks and the installations will begin immediately. Once windows are installed, the final plastering and finishing process of the building will begin. Work on the project has never stopped in spite of the major unforeseen building structural deficiencies found during different stages of the project, and taking into consideration the requirements to obtain mandatory inspections from the Special Inspector of record for the project and the Building Department. While from Washington Avenue it may appear that work has slowed, the majority of work being performed has been on the bottom two floors and ninth floor of the building which are hidden from view due to the scaffolding requirements of the project. With the structural repairs on-going and the final approvals of the windows obtained, the completion of the structural and fa9ade renovation project of the Historic City Hall Building is still on track and estimated to be substantially complete by December 2007. Attached are pictures of some of the structural problems encountered during the project. Should you have any questions about this project, please do not hesitate to contact me. JM~N Cc: Robert Middaugh Assistant City Manager Fred H. Beckmann Public Works Director Brad A. Judd Property Management Director Harvey Ruvin County Clerk F:lworkl$ALLI(1) EMPLOYEE FOLDERSIAIDA ORTIZlL TClltcoch.doc Ninth Floor: deteriorated terracotta brick and support beam Window: without lateral or vertical support Interior: window header beam deteriorated with exposed steel New block installed and columns and beams formed for concrete pumping. Concrete being pumped into forms. .'-- -~ f ..~ - ~ _.--L /' Completely restored wall including columns, beams, and blocks Southwest ground floor corner showing complete removal of walls and columns with shoring supporting the upper floor with corner column formed for concrete. ~ I '=-r Interior windows attached to metal studs. Severely deteriorated ground floor column Second floor restored, first floor demolished for reconstruction. Corroded steel beam Extent of corrosion causing steel beam to flake. HV AC equipment being lifted and placed into the building through a hole in the exterior wall. Fully restored first and second floor north wing including all columns, beams, and block work