Building Appendages (Balconies, Stairs, Etc.): Updates for Structural Engineers
Thursday, March 29th, 2018
In the several years since the June 2015 collapse of a Berkeley balcony and July 2015 collapse of a stair in Folsom, there has been increased activity in Northern California assessment, repair, and reconstruction of exterior elevated wood elements. From this increased activity has come better understanding of the type and frequency of issues that can lead to poor performance. This mini-seminar is intended to raise awareness and start discussion among the structural engineering community regarding the issues, both structural and multi-disciplinary, that affect performance. The presentation is intended to be of interest to practicing engineers involved in design of new wood buildings, and those involved in assessment and repair of existing wood buildings. The performance issues will be introduced through an overview of the presenters’ recent field observations, including the particular conditions contributing to poor performance of the Berkeley balcony. The presentation will also address assessment methods and lessons, recommendations for repair and reconstruction, and repair and reconstruction issues still being worked through. This presentation is drawn from the experiences and recommendations of the individual presenters, and does not reflect consensus positions of any committee.
- The performance issues - observed conditions
- Exposed framing
- Partially exposed framing
- Framing intended to be weather protected
- Lessons from the Berkeley balcony
- Assessment limitations and lessons
- Repair and reconstruction recommendations - the five Ds
- Issues still being worked-through
- Venting vs. fire rating
- Determining weather exposure
- Obtaining decay resistant framing
- Solid sawn framing vs. engineered wood
- Veneer plywood vs. OSB
- Fastener corrosion concerns
- Quality assurance
Kelly Cobeen, SE
Kelly Cobeen is an Associate Principal with Wiss Janney Elstner Associates in their San Francisco office, and is a registered Civil and Structural Engineer. Her work experience includes a wide range of project types, sizes and construction materials, with a special interest in seismic resistance of light-frame construction. She has been involved in numerous code development, research and educational activities, including updates to the NEHRP Recommended Provisions for Seismic Regulations for New Buildings, the ASCE 7 seismic provisions, numerous Applied Technology Council publications, and International Building Code and International Residential Code development, Kelly is coauthor of the Design of Wood Structures textbook, and is a past president and fellow member of SEAONC and SEAOC.
Andy Fennel, PE, CPEng, FIEAust
Andy Fennell is President and founding researcher of Engineered Research Group, Inc. (ERG). Andy has over 25 years of engineering and construction experience in the United States and Australia. Andy received his Bachelors of Civil Engineering degree from the Queensland University of Technology in Australia and is a Registered Civil Engineer in California, Hawaii, Nevada and Australia; a Licensed General Contractor in California; and an ICC-Certified Building Inspector.
Andy is an active member of SEAOC/SEAONC technical committees; is a frequent seminar presenter; and has been invited three times to Lecture at UC-Berkeley teaching their “Structural Design in Timber” Course. Andy’s anchor bolt research received multiple awards for engineering excellence and provided the basis for international building code changes.
Achim Groess is Vice-President and a Principal of Engineered Research Group, Inc. (ERG). Achim received his Bachelors of Science degree (Civil Engineering) from San Francisco State University.
Achim has over 25 years of engineering and construction experience in the United States and specializes in the planning, execution and reporting of forensic investigations. Achim has particular expertise in fenestration and building envelope performance and has testified as an expert-witness on these subjects.
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San Francisco, CA