Executive Summary - All 16 Field Review Reports
The project at 2951 Riverside (The Denbury) involves a multi-phase curtainwall refurbishment and replacement program managed by BPA and carried out by Lor-Issa Construction. Work spans from October 2025 through at least early April 2026 and covers three main scopes: interior sealant renewal at all stairwells and corridors, replacement of failed or cracked insulating glass units (IGUs), and full curtainwall frame replacement at the west elevation (Phase 1).
The project started with planning, sealant selection, and mock-up work. Exterior sealant testing confirmed that DOWSIL CWS silicone does not require primer on brick or concrete surfaces, a finding validated by a DOW representative through ASTM pull-testing. A retrofit black paint coating on all exterior metal frames was identified as a sealant adhesion risk and must be removed prior to application at all metal junctions. A loose vertical flashing was found at all stairwells and all levels and was recommended for full replacement.
Interior sealant work across all three stairwells and corridors was substantially complete by late February 2026. A quality deficiency was identified on February 23 when BPA found missing heel beads at corridor windows on Level 11. These were remediated and verified on February 26. A modified repair procedure was approved for the oversize IGUs above the 12th floor at Stairwell A to reduce the risk of breakage, using cap beads applied over the existing stops rather than removing them, with a proposed condensation pan as a backup measure. A formal deficiency review on March 24 identified 45 outstanding items across all three stairwells, including cracked IGUs requiring replacement, missing and inadequate sealant at perimeters and screw holes, and missing or incorrectly driven center screws at horizontal stops. One location in Stairwell B at Level 9/10 had received no work at all. BPA also documented 9 locations of wind-driven rain leakage across Stairwells B and C. Seven of these are attributed to defects in the exterior seals between the glazing assemblies and the surrounding structure, consistent with a 2023 investigation, and are expected to be resolved through the exterior repair work still to come. The remaining two leakage locations showed water on top of the glazing stops and are flagged as deficiencies requiring remediation.
Phase 1 curtainwall frame replacement at the west elevation began in February with brick demolition and progressed to the sixth floor of the "06" and "08" unit drops by early April, with Unit 708 in progress at the time of the most recent review. Two notable design refinements were implemented: jamb flashings were changed from a U-shape to sliding L-shaped flashings, and metal flashing closures replaced steel stud framing at bay window jambs, both BPA-approved. A masonry gap issue was identified at the "06" unit drop where the south-side brick gap widens by approximately 1 inch by the fourth floor, and BPA halted further brick cutting at this drop pending review. An interior finish revision at bay windows, eliminating short wall returns, was found to conflict with existing flooring terminations and was abandoned in favour of the original designed approach. Interior finish deficiencies in Unit 206 were identified and the contractor was directed to self-review all work before future BPA inspections. A significant flashing membrane quality issue was found at the "06" unit jambs from the fourth floor upward, with widespread problems including wrinkles, air pockets, unadhered sections, missing mastic at brick ties, gaps at floor transitions exposing insulation, and unsealed membrane joints. The contractor marked and agreed to remediate all deficiencies, and BPA approved a revised two-section membrane installation method subject to strict lapping and continuity requirements. Mortar quality issues at newly replaced brick above window lintels are deferred for a spring review and repointing.
Overall, the project is advancing but has entered a phase requiring closer quality oversight. Key items remaining include remediation of the 45 stairwell deficiencies from March 24, full remediation and re-review of the flashing membrane deficiencies at the "06" unit jambs, completion of interior finish deficiencies in Unit 206, completion of curtainwall installations across remaining unit drops with close-up membrane review ongoing from swing stage, resolution of the masonry gap condition at the "06" unit drop, spring review and remediation of masonry deficiencies, resolution of the oversize IGU repair at Stair A above the 12th floor through a Change Order, completion of exterior sealant repairs to address ongoing stairwell leakage, and final verification of all sealant and glazing work.
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FRR 16 - April 7 and 9, 2026 BPA conducted two site visits to review Phase 1 curtainwall replacement progress at the west elevation. By April 7, work was complete up to the fifth floor in the "06" and "08" unit drops, with Unit 608 in progress. A review of interior finishes in Unit 206 found the work incomplete, with outstanding deficiencies including unrepaired parquet flooring at the bay window, baseboard sanding and painting, a minor stipple ceiling repair, a gap in window perimeter sealant, and paint drips on the new curtainwall frame. The contractor agreed to address all items and committed to conducting internal self-reviews before future BPA site reviews. By April 9, work had advanced to the sixth floor with Unit 708 in progress. A swing stage review of the "06" unit curtainwall assemblies found the work generally in conformance, but the flashing membrane application at the jambs from the fourth floor upward was found to be broadly inadequate. BPA described the overall quality as disappointing. Specific deficiencies included membrane applied with wrinkles and air pockets, unadhered sections with brick dust on the substrate indicating insufficient surface preparation, mastic sealant missing around existing brick ties, gaps at floor transition areas leaving rockwool insulation exposed, and unsealed joints between existing and new membrane sections. The contractor marked all deficiencies on site and agreed to remediate them, with a self-review prior to BPA's follow-up. BPA approved a contractor proposal to install the jamb membrane in two sections per floor rather than as a single full-height piece, subject to shingle-style laps with no reverse laps, a minimum 6-inch overlap between sections, and maintained continuity between floors.
FRR 15 - March 31, 2026 BPA reviewed Phase 1 curtainwall replacement progress at the west elevation. Curtainwall replacement was complete in Units 106, 108, 206, 208, 306, and 308, with Unit 406 in progress at the time of the visit. Exterior review from ground level confirmed that metal flashing closures and self-adhered membrane were installed at all reviewed units, with a close-up swing stage review of the membrane to follow. Vision glass was installed in all fixed and operable sections, with spandrel glass temporarily retained using Dutchmen clips until full pressure plates and snap caps can be installed at the completion of each full vertical drop. A masonry gap issue was identified at the "06" unit drop: the distance between the new curtainwall framing and the remaining brick on the south side of the bay window increased by approximately 1 inch by the fourth floor, likely requiring more than a single brick width at the jamb. BPA directed the contractor to halt further brick cutting at this drop until the condition is fully reviewed. At the interior, finishes were substantially complete in Unit 208, ongoing in Units 206 and 306, and not yet started in Unit 308. A previously approved interior finish revision at the bay window in Unit 206, which eliminated short wall returns for a smoother drywall appearance, was found to conflict with existing flooring terminations and will not be carried forward in remaining units. The contractor will revert to the original designed approach with short wall returns. In Unit 308, foam insulation, Rockwool, and firestop sealant were confirmed installed at the spandrel level in accordance with project documents. Spandrel panels above Units 406 and 408 had been removed with temporary lumber shoring in place, but protective tarping had not yet been installed and remained outstanding.
FRR 14 - March 24, 2026 BPA conducted a formal deficiency review of sealant and IGU replacement work across all three stairwells, excluding the oversize top-floor landing units. A total of 45 deficiencies were found: 10 in Stairwell A, 21 in Stairwell B, and 14 in Stairwell C. The deficiencies fall into four categories: cracked IGUs requiring replacement (caused during stop removal), missing or inadequate sealant at perimeters and screw holes, missing or incorrectly driven center screws at horizontal stops, and one location in Stairwell B at Level 9/10 where no work had been completed at all. BPA also documented 9 locations of recently reported wind-driven rain leakage across Stairwells B and C. Seven of these involved water on landing floors at corners adjacent to the glazing assemblies, which BPA attributed to defects in the exterior seals between the assemblies and the surrounding structure, consistent with findings from a 2023 investigation. BPA noted these leakage paths are expected to be resolved once exterior repairs are completed. The remaining two leakage locations showed water on top of the glazing stops, suggesting a source within the glazing assembly itself, and both locations were flagged as deficiencies requiring remediation.
FRR 13 - March 23, 2026 BPA reviewed Phase 1 curtainwall replacement progress at the west elevation. At Unit 208, the previously installed flat window was reviewed from ground level and confirmed to have flashing membrane at both jambs and temporary plywood protection at the spandrel areas. At Unit 106, all three curtainwall frames and vision glass units were installed, sill membrane was applied, and interior finishes were being reinstated. At the bay window in Unit 106, the contractor used metal flashing closures at the jambs rather than steel studs and glass-mat board framing, a BPA-approved approach that improves workability and simplifies interior finishes. At Unit 206, abatement enclosures and drywall removal were complete, temporary plywood and lumber shoring were in place at the spandrel opening, and the remaining cleaning was to be completed that afternoon.
FRR 12 - March 18, 2026 BPA reviewed the oversize IGUs at Stairwell A, at the landing above the 12th floor, where standard stop-removal procedures carry a high risk of IGU breakage. The risk stems from hardened sealant and spray-applied foam that had been retrofitted behind the stops at some locations in the building, making removal difficult. Because replacement IGUs at this overheight location are extremely costly and historically have resulted in the undesirable practice of splitting the unit into two panes with an improvised rail, BPA recommended a modified repair procedure. The stops are to remain in place, and instead two new cap beads are to be applied, one from stop to glass and one from stop to frame, along with sealing of existing screw holes. As a backup measure, BPA proposed installing a condensation pan along the base of the IGU. A Change Order will be required to implement this modified approach.
FRR 11 - March 16 and 18, 2026 BPA attended on two days to review the start of curtainwall replacement at the west elevation. On March 16, BPA observed abatement enclosures in place at Units 106 and 108 and brick removal ongoing at the "11" unit drop. Curtainwall replacement work started on March 18 after a one-day wind delay. At Unit 208, directly above the west exit door, the existing frame was removed, self-adhered membrane flashing was installed at the sill and jambs, a metal L-angle was installed at the rough sill, and the new curtainwall frame was secured with structural anchor plates. Vision glass was installed in both fixed and operable sections. Jamb flashing was revised from the mock-up's U-shaped design to two sliding L-shaped flashings, a BPA-recommended change that allows adjustment for varying gap widths between the steel stud and frame. Several items remained incomplete at the time of review, including end dams and closure flashings, and were to be reviewed on a subsequent visit.
FRR 10 - March 5, 2026 BPA reviewed brick demolition progress at the west elevation curtainwalls. Saw-cutting at the "06," "08," "11," "13," and "15" unit drops was confirmed as straight and well executed. Brick removal had commenced at the upper floors of the "06" and "08" drops, with the demolition carried out carefully and without visible damage to adjacent materials or brick ties. However, fragmented brick and mortar debris were found behind remaining brick in localized areas, and the contractor was directed to keep the work area clean. At newly replaced brick above the lintels of the "06" drop, BPA found debonded mortar joints, a mismatched mortar colour compared to existing brick, and efflorescence staining. No remedial work was to proceed until a spring review after cleaning, at which point repointing to a depth of 1 inch for debonded areas and 1/2 inch for colour mismatch areas would be directed.
FRR 09 - February 26, 2026 BPA returned to verify that the heel bead deficiencies found in FRR 08 at Level 11 corridors had been corrected. The contractor confirmed that sealant work was complete on all floors except Level 11, and the remediation of the deficient heel beads was reviewed and found to follow the correct procedure, including placement of backer rod prior to sealant application. BPA also reviewed an IGU replacement nearing completion at Stairwell C, Landing 4/5, and confirmed proper glazing tape placement and compression. It was noted that the additional central screws at the horizontal stops had not yet been installed and would need to be completed.
FRR 08 - February 23, 2026 BPA conducted a broad review of interior sealant work and IGU replacement progress across all stairwells and corridors. Approximately 10 of 26 stairwell IGU replacements remained outstanding. The contractor confirmed a pace of 2 to 3 units per day. A significant quality issue was found in the corridor sealant work: at Corridor B Level 11, the heel bead was only present at the bottom of the IGU, and at Corridor C Level 11, the heel bead was entirely absent from the IGU perimeter. BPA also documented 8 cracked IGUs across Stairwells A, B, and C, and identified newly fogged units at Stairwell A Level 10/11 and at 2 to 3 locations in Corridor A.
FRR 07 - February 11-12, 2026 BPA reviewed interior sealant work progress at Stairwell B and observed two IGU replacement mock-ups, one at a corridor window and one at a stairwell window. The contractor reported that interior sealant work was complete in Stairwells A and C and nearly complete in Stairwell B. At the corridor IGU replacement mock-up at Corridor B Level 12, BPA issued site instructions covering full surface cleaning, heel bead application, sealing of all screw holes, and confirmation that no sealant bead is needed at the vinyl stop-to-frame junction. At the stairwell IGU replacement mock-up at Stairwell A Level 8, the contractor used a suction cup and heat gun to remove the existing unit, placed EPDM setting blocks and backer rod, installed the new IGU with glazing tape, and applied both a heel bead and a perimeter cap bead. The work was documented as completed.
FRR 06 - February 4, 2026 BPA reviewed the site mobilization and start of brick demolition for Phase 1 of the curtainwall replacement at the west elevation. Two swing stages were set up, but BPA identified a safety deficiency: only one of the two swing stages had protective fencing installed around it. The contractor was directed to install fencing around the second stage immediately. A second safety issue was noted when the Sea-Can storage container was found with its door wide open. The contractor was reminded to keep it secured at all times. Saw-cutting of vertical joints along both sides of the curtainwall was observed to be well executed.
FRR 05 - January 29, 2026 BPA observed the interior sealant renewal on a single IGU at Stairwell A, Level 3. The work followed the procedure approved in FRR 04. Notable site conditions included a blocked screw hole containing a sheared screw, which required drilling a new adjacent hole. The contractor also noted that stop attachment conditions vary considerably across the building, with some locations requiring significantly more removal time. The heel bead was wet-tooled using isopropyl alcohol applied to the tool rather than the work surface. The DOWSIL Contractors Weatherproofing Sealant was confirmed as the product used for all interior sealant work.
FRR 04 - January 15, 2026 BPA reviewed the interior refurbishment mock-up at Stairwell C, 9th floor landing. The work involved progressively removing interior aluminum stops, cleaning all contact surfaces, applying a sealant heel bead around the full IGU perimeter, sealing all screw holes, reinstating the stops with new glazing tape, and applying a cap bead at the stop-to-frame joint and at the split mullion joint. BPA issued a site instruction confirming that the shim space between the IGU and the frame is not to be filled with sealant, as the heel bead and exterior cap bead together provide adequate protection. A second site instruction required the addition of a third screw at the midpoint of each horizontal stop, as the existing two-screw pattern was found to be inadequate. BPA assessed the mock-up as acceptable.
FRR 03 - January 12, 2026 BPA attended the site with Lor-Issa and a DOW representative to conduct formal pull-tests on the mock-up sealant from FRR 02. Five locations were tested following the ASTM C1521 Method A procedure. The DOW representative's preliminary findings indicated that all five tests passed, which means primer is not required at brick or concrete interfaces. Glass-to-metal beads were not tested and the DOW representative recommended increasing their size to approximately 1/4 inch thick for future work. The DOW representative was to provide an official report to confirm these findings. Interior sealant work was scheduled to begin January 14, 2026.
FRR 02 - November 28, 2025 BPA attended a sealant mock-up at the ground level exterior of Stairwell A. The team tested sealant application on six substrate combinations: glass to metal, metal to metal, brick to metal with and without primer, and concrete to metal with and without primer. The mock-up followed a thorough surface preparation process using wire brushes, isopropyl alcohol, and DOWSIL Construction Primer P on porous surfaces. A key finding was that all exterior metal frames are coated with a retrofit black paint that is flaking in places and is not a suitable sealant substrate. A loose vertical flashing between the IGU frame and the brick wall was also identified at this location, and the same condition was confirmed to exist at all stairwells on all levels. Lor-Issa was directed to contact a DOW representative to verify curing times and confirm whether primer is required through adhesion testing.
FRR 01 - October 8, 2025 BPA met with Lor-Issa Construction on site to plan the start of work on the stairwell and corridor glazing refurbishment. The team confirmed that swing stage mobilization would begin the week of October 14, with exterior work starting October 22 at Stair C. Key decisions included selecting DOWSIL CWS silicone as the primary sealant and Tremco Dymonic 100 polyurethane as a backup for masonry surfaces. BPA noted that replacement IGUs would be slightly thicker than the existing ones, which could affect screw alignment in the glazing stops. The team also flagged two atypical conditions for future review: a corridor window at Stair B 2nd floor where roof flashing extends onto the glass surface, and a stairwell window at Stair B where the glazing seal had been pushed out by glass vibration.
IGU-Focused Summary
IGU work on this project covers two related but distinct scopes: interior sealant renewal around existing IGUs, and physical replacement of failed units.
Interior sealant renewal was the first IGU-related scope to be executed and was completed across all stairwells and corridors by late February 2026. The approved procedure involves progressively removing aluminum or vinyl stops, cleaning all contact surfaces with isopropyl alcohol, applying a heel bead at the IGU-to-frame perimeter, sealing all screw holes, reinstalling stops with new glazing tape, adding a third screw at the midpoint of each horizontal stop, and applying a cap bead at the stop-to-frame joint. BPA confirmed that the shim space between IGU and frame must not be filled with sealant. A quality deficiency was found on February 23 at Level 11 in Corridors B and C where heel beads were partially or entirely missing. These were remediated and verified on February 26.
IGU replacement began in parallel with sealant work. Of 26 stairwell IGUs scheduled for replacement, approximately 10 remained as of February 23, with the contractor completing 2 to 3 units per day. The process involves using a suction cup and heat gun to loosen and remove the existing unit, placing EPDM setting blocks at the sill, installing glazing tape on the frame and stops, fitting the new IGU, applying a heel bead and cap bead, and installing the additional central screws at horizontal stops. A recurring complication was that all removed units had sealant rather than glazing tape between the stops and glass, requiring extra time and effort. At one location at Stairwell C Level 11, a grinder was needed to free the unit after a heat gun proved insufficient.
Eight cracked IGUs were identified across Stairwells A, B, and C during the February 23 review, and additional fogged units appeared at Stairwell A Level 10/11 and at multiple locations in Corridor A, consistent with the cold weather conditions. These failures were anticipated from the outset of the project and are being tracked.
The most complex IGU situation is at the oversize units at Stairwell A above the 12th floor. These units are very tall, difficult to access, and carry an extremely high replacement cost. Past replacements at this location were done by splitting the oversize unit into two panes with an improvised rail, which BPA described as an undesirable outcome. The stops at this location contain spray-applied foam and removing them risks breaking the glass. BPA's approved solution, documented in FRR 12, keeps the stops in place and applies two new cap beads, one from stop to glass and one from stop to frame, along with sealed screw holes and a proposed condensation pan at the base as a backup drainage measure. A Change Order is required to proceed with this modified approach.