Reserve Funds

June 24, 2024 Published by Toronto and Area Chapter - By Sophia Rojenko

Reserve Fund Study Report Card: Post-tensioned Buildings

From the Spring 2024 issue of CCI Toronto Condovoice Magazine.

Beware of Post Tensioned Structures

Site Description

The corporation consists of a 20-storey tower with 140 residential units, and a three-level underground parking garage. The building was built around 1980. The suspended slabs in the garage, as well as the tower floor slabs have post-tensioned (PT) reinforcing.

Reserve Fund Assumptions

PT reinforcing involves high strength multi-strand cables that are stretched to induce tension after the concrete slabs are cured and remain in a stressed condition for the service life of the structure. These cables require periodic evaluation to check their condition and confirm that they remain adequately stressed. The reserve fund study (RFS) recommended periodic PT evaluations for the garage and tower slabs and included forecasts for future repair costs.

The Reality

The most recent PT evaluations found that there were several broken cables in the parking garage slabs, as well as a broken cable in a tower floor slab. A structural evaluation was completed and determined that repairs were needed. While the PT evaluation could not be finalized until after the RFS was finalized, the preliminary budgets included in the RFS were close enough that the findings did not trigger an interim study update.

Post-tension cable anchors prior to stressing within a parking garage slab. Taken during a localized repair project.

Lessons Learned for Reserve Fund Planners

Some condominiums in the GTA have PT structures. Many of these were built in the 1980s. When preparing a RFS, the structural drawings should be reviewed carefully to confirm if PT was used. Typically, these buildings have PT garage slabs and tower floor slabs, and conventionally reinforced garage roof and tower roof slabs. However, in some cases, the garage slabs may be conventionally reinforced, and the tower slabs post-tensioned.

It is more common to find issues with garage PT slabs, compared to tower PT slabs because garages are subjected to water and salt (used for de-icing). Nevertheless, PT systems in tower slabs should not be ignored. You should recommend periodic PT evaluations. Ideally, these evaluations would be completed just prior to the site review RFS so that the RFS can accurately reflect the findings and repair budgets.

Takeaways for Board of Directors and Property Managers

Ensure that the corporation’s engineer is provided with a set of structural drawings for the building. If you don’t have a copy, they can typically be obtained through a land registry office or the municipality.

Ensure that PT evaluations are completed as recommended by the corporation’s engineer, and that repairs are carried out, under the supervision of an engineer, as necessary.

Sophia Rojenko is a Project Manager at Synergy Partners. In her role, Sophia has participated in preparing dozens of reserve fund studies. She has experience in understanding Declarations, Shared Facilities agreements, and condominium legislation and regulations.