Mock-Ups: Essential to Remedial Design (2020 Region V Meeting)

What appeared to be a simple reroofing job at a 51,000-square-foot institutional facility turned into four years of research and design to determine the best possible solution.

The existing roof on an institutional facility in California’s Central Valley had reached the limits of its existing useful service life and had several leaks. The roof contained thousands of penetrations, including façade access davits, guardrails, guard walks, solar hot water heaters, vents, communication lines, etc. The original roofing system consisted of liquid-applied roofing in an inverted roofing membrane assembly (IRMA). The inherent function and conditions of an institutional facility presented a long list of restraints. The facility was overcrowded and contained a laundry facility, health care units, kitchen, locker room, exercise facilities, and court room. Restraints included: odor, delays due to security clearances, number of penetrations, schedule, and costs.

Several performance mock-ups were done to test for removal of the existing membrane, adhesion, and odor. Different roofing systems were tested, including poly-methyl methacrylate (PMMA), polyurethane, and styrene-butadiene-styrene (SBS) modified-bitumen roofing. Several issues were discovered during the mock-ups, including vapor drive and dust control. Without performing these mock-ups, the project could have been mired in delays and change orders.

This presentation will present the case that mock-ups, surveys, and investigations are essential for any remedial work. With the increasing need to renovate and convert existing buildings, mock-ups become more and more necessary. Spending time and money upfront will help to save time and money in the future.

Learning Objectives:

1. Understand to identify and prioritize constraints on a project that are essential to design.
2. Understand various test methods for liquid-applied roofing application.
3. Understand how mock-ups can be utilized to verify or determine existing conditions for remedial projects.
4. Understand how mock-ups can help identify unknowns that can lead to costly change orders.

Erica Reynolds, PE

McGinnis Chen Associates, Inc. | Long Beach, CA

Ms. Reynolds is a registered professional engineer in the state of California and an associate at McGinnis Chen Associates. She heads MCA’s Southern California office, based out of Long Beach. Mr. Reynolds joined the firm in 2013 and has managed numerous design projects and performed investigation and evaluation on many building assembly systems, including roofing, plaza decks, exterior wall assemblies, and skylights. Erica earned a bachelor’s degree in civil engineering from Cal Poly San Luis Obispo and a master’s degree in structural engineering from the University of Southern California. She is also the official event coordinator and plans office get-togethers and parties