Three-story condo goes green

By Evelyn Witterholt. 

Learn how this Portland condo was able to fix their roof leaks while salvaging existing materials and preventing occupant displacement. 

At a three-story condo in Portland, Oregon, residents were experiencing major water intrusion problems with their vegetative green roof. Not only did this problem mean revenue loss for the property owner, but it also meant having to potentially displace current residents during the re-roofing process. But thanks to the help of VaproShield®’s products, a portion of the existing roof materials were saved. 

The existing roof on the condo was composed of an interior gypsum ceiling, spray polyurethane foam (SPF), two layers of plywood, polyisocyanurate insulation, gypsum coverboard, TPO single ply membrane and a vegetative green roof layer on top. Unfortunately, excessive moisture seeped through many of these layers caused by damaged membrane laps and punctures.  

The roofing contractor decided that the best solution for the roof was VaproShield’s SlopeShield Plus SA air barrier and permeable vapor retarder with self-drying technology. Rather than having to completely replace the plywood on the existing roof, SlopeShield Plus was directly applied to the damp plywood allowing it to dry out over 45 days while providing temporary weatherproofing. The closed cell foam created a vapor barrier which helped negate downward drying. The air/moisture control membrane also provided air tightness and vapor diffusion allowing the plywood deck and underlying materials to dry out.  

Thanks to SlopeShield Plus SA, the plywood, SPF and interior gypsum ceiling could all be saved. Ultimately, permitting the existing components to be re-used in the roofing system significantly reducing the cost and timeline of the project. This meant there was minimal impact to occupants during the re-roof process. The existing plywood underneath met its target moisture content from 45% to 15% in 45 days. This moisture reading was taken using a Delmhorst BD-2100 moisture meter. Over the SlopeShield, the contractor also installed new layers of polyisocyanurate insulation, gypsum coverboard, PVC roof membrane and a vegetative green roof layer.