FORSMITH Building Science Consultants (FORSMITH) was challenged with a complex multi faceted building envelope forensic restoration including a full design and specification for the selective demolition and forensic rehabilitation of a 100-unit apartment building exterior envelope. Our team and network developed the best possible solution beginning in 2017 and extending through to the spring of 2019, after in-depth forensic investigation and analysis was completed. The implementation of our solution will begin in late 2019 with an anticipated duration of 24 months. FORSMITH's history with the building dates to 2017, after receiving a call from the client to investigate brick spalling.
Upon initial investigation, FORSMITH found that the exterior of the building, including the brick veneer and roof, had suffered from deferred maintenance during its current lifespan of 40+ years. The parapet around the entire roof perimeter was in disrepair and was allowing moisture to intrude and severely degrade the wall assembly – leading to many other issues. Water was migrating into the building interior at multiple locations, bricks were spalling off the building façade, mortar joints were severely cracked, steel shelf angles and lintels were corroded to a critical point, roof membranes were deteriorated, and air exfiltration through the building envelope was extremely high. Other material issues include failed sealant at windows, flashings, transitions, seams, penetrations, etc. allowing water to infiltrate into the roof and wall systems. Additionally, various roof-top equipment and associated penetrations were not installed correctly or had failed, there were inadequate, or no, through-wall flashings installed which contributed further to these issues. In short, the building was falling apart and the many issues with the building were the problem that FORSMITH had to solve cost effectively.
The main challenge FORSMITH was faced with was designing the building’s rehabilitation in a way that minimized the impact on the building’s tenants and the Client, to allow the building to operate and function while undergoing forensic restoration. Both the wall and roof assemblies needed immediate restoration. Fenestration replacement, balcony slab and guardrail repairs were also to be included in the project.
FORSMITH's internal and external resources worked together as a team, in collaboration with the Client, to develop a solution for this massive project. We are known for being able to solve problems that no other firm can, and we designed the best solution, again. The first item was to design a suitable Protected Membrane Roof Assembly (PMRA) to prevent further moisture migration from occurring via the roof components and parapet to reduce the buildings exterior deterioration while simultaneously fixing all other issues associated with the roof while also keeping in mind what would be required for future remediation of the building envelope. FORSMITH then looked to design the remediation of the building envelope, as our assessments and investigations have determined that it is in extremely poor condition. As part of the building envelope remediation, we will inspect all the shelf angles to determine adequacy, and those with substantial section loss will be replaced. Areas of brick will be removed and replaced once the shelf angle capacity is verified. Our design also allows for a staged approach to the remediation to spread the capital expenditures over multiple years with the intent that long term resurfacing of the exterior façade will be completed with an Exterior Insulation and Finishing System (EIFS), providing a future vision of a fully functioning and aesthetically pleasing exterior building envelope.