Malcolm Yonge arches near failure condition

Inweekly requested the structural assessment of the Malcolm Yonge Community Center that was closed in late March. According to the initial inspection by Joe Dereuil Associates, the seven arches were severely damaged and rated in near failure condition. The engineer recommended an evaluation of the entire facility – which was constructed around 1961 – to determine whether it can be rehabilitated or should be demolished.

From the report:

Te damage to the arches involves heavy decay, severe delamination and have produced some deflection. The delamination and decay are worst on the exposed (exterior) portion of the arches. The gaps caused by the worst delamination measure up to 1/4” wide and continue across the full width of the member. The arch delamination and moisture damage continue inside the building, or past the drip edge for 5 to 15 feet, or more, depending on arch location. The damage to the glue-laminated arches is severe and as a result, the building is not safe for occupancy.

Read MalcolmYonge_Glulam_Arch-StructuralReport

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Executive Summary:

The seven (7) glue-laminated wood arches supporting the roof are severely damaged. The damage is the result of long-term moisture exposure combined with the accompanying effects of certain wood-destroying organisms. The condition of the arches is very poor and they are nearing failure. The building is thereby deemed unsafe for occupancy. Temporary shoring will be required at all arches if repairs are attempted.

Our structural condition survey of the arches is presented as Exhibit A to this document and addresses arch deflection, delamination, and decay. The overall rating for all seven arches is 20. This rating represents a (near) failure condition. This rating system is based on NAVFAC MO-111.1, Inspection of Wood Beams and Trusses.

We do not yet know if partial replacement and/or strengthening of the arches will be deemed economically feasible, however the general approaches to repair may involve the following.

Glue laminated wood arches may be repaired by replacing sections/segments of the arch, paying close attention to the jointing details. Joint details may involve steel rods, steel plates, bolts, screws, FRP, and/or glue. Alternatively, they may be strengthened/supplemented with structural steel shapes including hollow structural shapes, steel channels and/or plates.

It is recommended that the condition of the entire facility be evaluated as a subsequent task to this initial limited assessment to determine if it is feasible to repair/rehabilitate or if it would be better to demolish and rebuild. The recommended evaluation should include a study of walls, roof, windows, doors, flooring, plumbing, hvac and electrical systems along with continued assessment of the interior and under-roof portions of the arches. We anticipate replacement of the windows on the east/west walls. We were informed that one of the HVAC units is not operational. A comprehensive repair cost estimate should be prepared and evaluated as part of the feasibility study and must include structural and non-structural components.


List of Deficiencies

Structural deficiencies include decay, delamination and deflection of seven (7) glue-laminated wood arches as described in Exhibit A, Inspection Condition Rating Chart. This damage is present in the exposed portion of the arches, outside of the edge of the building roof but also extends into the condition portion of the building a limited distance.

We also noticed stair-stepped cracking of the exterior concrete block wall located on the west side of the north lobby entrance.

There is termite damage to some of the casework around the north lobby entry doors.

While not in our scope of work, other potential non-structural deficiencies may be identified in subsequent or supplemental assessments by others and could include termite damage to casework, faulty windows, inoperable HVAC systems or other components.


General Recommendations

We recommend that the building not be occupied at this time. It should be temporarily shored up if occupancy is required for any length of time such as during the future assessment or repair phase.

An inspection of the entire facility for wood destroying organisms should be conducted by appropriate personnel and a report provided.

We recommend proceeding with a continued comprehensive building assessment to include all structural and non-structural systems. The comprehensive assessment must include a cost analysis addressing all required repairs.

The feasibility of repair versus demolish/rebuild should be evaluated and presented as part of a comprehensive building assessment.

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