Issue link: http://digital.nexsitepublishing.com/i/1127356
T he 272-unit McGuire Apartments building was constructed in Seattle's trendy Belltown neighborhood for $32 million Just three years after completion, post-tensioned load-bearing cables supporting the concrete floors started showing signs of serious corrosion Concrete chunks fell from upper floors, smashing into the sidewalk below It was estimated that one third of the cables would fail by 2019 The corrosion was due to improper cable end grouting, a repair estimated to cost $80 million— more than twice the original cost of the building In 2012, the building was demolished floor by floor Sadly, a construction worker was killed during demolition operations Similar projects in San Francisco, Las Vegas, and Corpus Christi also experienced structural failures in recent years These high-profile, well-funded developments had the best engineering teams, Protect your business and reduce your risk at 2-10.com/builders Avoiding Multifamily Construction Calamity BY WALT KEAVENY, MS, PE, PG RISK MANAGER AND PRINCIPAL ENGINEER 2-10 HOME BUYERS WARRANTY highly skilled builders, and intense building authority scrutiny, and yet were total losses due to seemingly simple causes like foundation depth, corrosion protection, and rebar orientation Builders often mistakenly believe building envelope deficiencies and water penetration represent their greatest risks These issues can be problematic, but liability rarely rises to the level of structural failures Major structural failures are often newsworthy, reputation damaging, and expensive Smaller projects face similar risks on more limited budgets For example, smaller buildings may lack a geotechnical investigation In these cases, if a builder selects the least conservative foundation option proposed by the engineer, the risk for foundation failure rises significantly Smaller buildings may also lack budgets for critical construction inspections The best design can result in an unsatisfactory structure if poorly built Inspections improve their chances for compliance with plans and specifications Finally, smaller builders may neglect to purchase commercial general liability insurance and insurance-backed structural warranties Multifamily builders can manage their risk by following these best practices: • Conduct a geotechnical investigation to explore unknown subsurface conditions and design a cost-effective, appropriate foundation • Implement an effective construction quality assurance program to confirm compliance with plans and specifications, utilizing the engineer(s)-of-record and skilled independent inspectors • Use subcontractor agreements and purchase a commercial general liability wrap policy that includes coverage for all subcontractors • Purchase an insurance- backed, 10-year structural warranty with written performance standards and binding arbitration Your small multifamily building may not have 25 floors, but the inherent risk for a major structural failure is comparable to much larger buildings Embracing best practices will improve your chances of constructing a building that stands the test of time In recent years, an alarming number of large, high- profile, multifamily structures have failed. What causes these failures and what can smaller multifamily builders learn from them? Total Losses From Simple Causes Rebar Orientation Foundation Depth Corrosion Protection Your small multifamily building may not have 25 floors, but the inherent risk for a major structural failure is comparable to much larger buildings. 58 master builder SUMMER 2019 membership value