Exterior Wall Retrofit

Title: Exterior Wall Retrofit

Award Category: Building Enclosure

Project Address/Location

2770 Aquitaine Ave.

Mississauga, Ontario L5N 3K5
Canada

Submitted By: Jee Young Kim

Company Info

Pretium Engineering Inc.

540 Bingemans Centre Drive
Unit 100
Kitchener, Ontario N2B 3X9
Canada

9052206873

[email protected]

Project Description and Background: Pretium was engaged to address persistent water infiltration and deterioration in the building enclosure. Despite prior repair attempts, water ingress remained a significant concern, contributing to ongoing issues like cracked and bulging exterior walls, drafts, and further infiltration. The building’s windows and balcony sliding doors had begun to fail, along with the guardrails, waterproofing systems, and balcony slab concrete. The complex nature of the project stemmed from the need to mitigate these failures while minimizing disruption to residents. Additionally, the site presented unique challenges, such as maintaining building accessibility and managing the risks of working in an occupied, high-traffic area. Pretium’s expertise was essential in devising a comprehensive solution that addressed both the structural deficiencies and the need for long-term durability.

Scope: Due to ongoing concerns with air drafts, water infiltration, and the ineffectiveness of previous repairs, a consultant, Pretium, was engaged to provide a comprehensive solution. The building faced widespread issues, and a thorough investigation was required to uncover the root causes. Pretium’s team conducted site inspections with the assistance of a contractor to provide access and strategic wall openings, which revealed significant corrosion in the building’s structural studs, with some steel studs/tracks having full section loss. Water had become trapped within the wall assembly, causing severe damage and accelerating deterioration. Given the extensive scope of problems, including the failure of several building systems simultaneously, Pretium recommended a large-scale restoration project. This approach was necessary to address the end-of-service-life conditions in multiple systems—such as windows, doors, waterproofing, concrete structures, and guards —and ensure proper integration between them moving forward. To guide the restoration, Pretium developed a detailed scope of work that included both diagnostic testing and comprehensive design solutions. Diagnostic testing focused on identifying moisture pathways and assessing the performance of the enclosure, with particular attention to air and water infiltration points. Thermal imaging was reviewed to locate areas of thermal bridging. Based on these findings, Pretium prepared detailed design documents to ensure that all critical interfaces between systems were properly detailed to prevent future issues. A mock-up was completed at the bay window drop by installing a new window wall assembly. Based on the thermal imaging, drafts, and moisture pathways we modified the design to remove the window wall and construct a new wall assembly complete with punched window to provide a more durable and resilient solution. This solution was then modelled using the RETScreen modelling platform to determine the energy and carbon reduction impact of the proposed project. A savings of approximately 11.5% was estimated. Based on these savings, Pretium assisted the client with an application to the SaveONEnergy program, providing all details and documentation necessary for the project to be approved for a financial incentive of approximately $42,000. Additionally, the project is expected to save the building $17,500 annually, escalating to nearly $28,750 by the year 2035 as a result of current carbon pricing forecasts.

Solution: A large-scale building enclosure restoration was undertaken, involving window and sliding door replacement, guardrail replacement, concrete balcony repairs, balcony waterproofing, sealant replacement, through-wall repairs to corroded studs, removal of localized window walls with new stud wall assemblies with punched windows, EIFS overcladding, and new metal flashings. The scope of the project focused on improving both the building's performance, resilience, and aesthetics, while minimizing disruption to residents. One innovative aspect was the reconfiguration of the bay windows. The original window wall assemblies were removed and replaced with new stud walls complete with EIFS and punched windows, all in the course of a single workday. This minimized disruption, allowing residents to reenter their units the same day. The change not only increased the structural stability of the wall assembly but also significantly improved the thermal performance of the building. To manage water, new sealant diverters were installed at the balconies to direct water away from the adjacent EIFS that protruded beyond the slab edge. Additionally, metal flashing and sloped diverters were introduced to shed water off the building efficiently, reducing moisture exposure to the EIFS and limiting long-term deterioration risks. The new EIFS overcladding provided multiple benefits: enhanced thermal performance, improved air-tightness, reduced water infiltration, and superior soundproofing. By improving the building's insulation, heating and cooling demands were reduced, contributing to energy savings and a more comfortable living environment. The overcladding also refreshed the building's appearance, giving it a modernized look that aligned with current architectural trends. The EIFS at ground floor and tenant accessible areas were reinforced with additional heavy mesh which allowed for a more durable cladding at these locations. Throughout the project, rigorous commissioning and testing were performed to ensure the implemented solutions met performance expectations. Water penetration tests, air leakage tests were completed at windows. Thermal imaging was conducted from the exterior and interior to flag any sources of drafts and to improve the buildings energy efficiency. While the final solution largely adhered to the original design, some adjustments were made based on field conditions. For example, unforeseen corrosion in some structural areas required additional reinforcement, and uncovering live electrical buried in the window walls that were being replaced. These real-time adaptations ensured that the implemented solution was both durable and efficient. Overall, the project combined state-of-the-art materials with thoughtful design and value engineering to deliver a solution that addressed both the building's technical challenges and the aesthetic needs of the client. The improvements in energy efficiency, water management, and building aesthetics represent a notable achievement in building enclosure restoration.

Value: The consultant played a crucial role in the success of the project by providing expert guidance in resolving complex details between new and existing building systems. Our involvement ensured that all design and construction phases were coordinated effectively, particularly when dealing with unforeseen site conditions. One significant challenge was the discovery of electrical wiring within the wall assembly of certain window wall sections that were slated for reframing. The consultant quickly adapted the design to accommodate these unexpected conditions, ensuring the project remained on schedule and within scope. The consultant’s expertise was also essential in coordinating the efforts of various trades, including multiple foremen and subcontractors, to ensure that the work was completed in the correct sequence. This involved carefully staging the project so that different building elements—such as windows, guardrails, EIFS, and waterproofing systems—could be installed efficiently while maintaining the integrity of the enclosure throughout the process. For example, we developed strategies to remove and replace windows without pre-existing samples for mock-ups, ensuring proper fit and functionality while minimizing disruption to the building’s occupants. One of the most notable contributions of the IIBEC-certified consultant was their attention to detail in addressing the critical interfaces between new and existing systems. By carefully managing these transitions, they ensured that the new elements, such as windows and EIFS cladding, would integrate seamlessly with the existing structure, providing long-term durability and performance. Their deep knowledge of building envelope science allowed them to design solutions that improved air and water tightness, enhancing the overall energy efficiency of the building. We conducted ongoing reviews and inspections throughout the construction process, adding value by identifying potential issues early and ensuring they were addressed before becoming larger problems. our involvement ensured that all repairs were executed according to design specifications and industry best practices, reducing the risk of future maintenance issues. Furthermore, the way we facilitated communication between the project team and the client was instrumental in keeping the project on track. They provided clear explanations of technical issues, helping the client understand the reasoning behind design decisions and any necessary adjustments. This collaborative approach ensured that the project was delivered successfully and met the client’s expectations. In summary, the IIBEC-certified consultant’s involvement added tremendous value to the project by providing innovative solutions to complex problems, ensuring coordination among various trades, and maintaining a focus on performance and long-term durability. Their expertise in building enclosure design and construction was essential to the project’s success, resulting in a high-quality restoration that will serve the building and its occupants for many years. This version highlights the consultant's critical contributions, from addressing unforeseen issues to ensuring seamless coordination and performance improvements, while emphasizing the importance of the IIBEC member's involvement.

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Additional Info: We would like to thank the following additional team members from Pretium who assisted with the success of this project as well as with the contents of this application: Michael Piccin, P.Eng. - Project Principal Robert Dziurdzik, P.Eng., BSS - Project Manager Jennifer Hogan, B.Arch.Sci., C.E.T., REWC, RRO, CRE, LEED AP, Certified Passive House Consultant - Energy Modelling Project Principal Anna Dziurdzik, Certified Passive House Consultant - Energy Modeller

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