NV5 Forensic Engineering and Building Consulting received a request from a law firm representing an insurance company to investigate a cast iron drain pipe system that allegedly caused a water backup into the interior of a residence.
A building science expert with NV5 was tasked with determining the cause and origin of a reported drain backup and if the interior damages were related to the reported backup. The homeowner’s attorney had a camera inspection conducted on the residence’s drain pipes. The attorney reported the cast iron pipes were damaged and needing replacement. The damage resulted in a backup into the residence with subsequent water damage. The attorney provided a $90,000 estimate for replacement of the cast iron pipes and repair of the interior damages. Working with a subcontracted plumber, NV5 personnel determined that the cast iron drain pipes were intact and undamaged. Through the video camera inspection and direct observation from the crawl space NV5 revealed that the reported slow drainage was caused by an improper slope of the drain pipe.
The insufficiently sloped drain pipe caused chronic water retention and drainage obstructions from the laundry room, and these conditions were unique to that part of the residence due to its lower elevation. The expert continued to investigate the interior damages from the reported drain backups and discovered the damages were caused by improper installation of the HVAC ductwork that allowed the flooring to reach dew point temperatures resulting in condensation. Additionally, the expert used UV light to reveal that the moisture damage to the interior furnishings and building materials was caused by pet urination.