Boreal Centre Cable Truss Lift

PROJECT BACKGROUND: The BCBC (Boreal Centre for Bird Conservation) is a Gold Leeds building that incorporates an inverted roof supported by Glue Lam Beams and ½ Cable Trusses. Winter snow load was very excessive stretching the cables, lowering the center of the inverted roof line by 4 inches.

PROJECT OBJECTIVE: Raise the trusses and tighten the threaded swage connecters at each cable end to lift the roof back into place.

SCOPE OF WORK: Contractor is responsible for all necessary equipment, tradesmen, and supplies for the completion of the following scope of work:

1. Blocking to be installed between the individual top chord 2x8 members. Blocking will be spaced no further than 1.5m apart along the length of the top chords. Blocking to be installed prior to raising the trusses with oversight from a professional engineer, supplied by parks.

2. Shore each truss at the mid-span to incrementally lift trusses a total of inches vertically. Shoring to be raised so that adjacent trusses are lifted simultaneously, avoiding differential height changes of more than 2 inches between adjacent trusses.

3. Cables to be tightened while the trusses are slowly raised, equally at each end of the truss. Tighten each cable one-half rotation before tightening the next cable to maintain equal tension between cables. The cables are to be tightened slowly and evenly until load on the shoring has been reduced, this is tested by dropping the shoring slightly, the truss should settle only slightly once the cable has reached an ideal tension.

4. This procedure will be overseen by a professional engineer supplied by Parks.

All debris and garbage disposal is the responsibility of the contractor.