2003 Beca Structural Engineering

Report

Church College of New ZealandDavid O McKay Building

One of two massive trusses between the Gym and Auditorium.  You can see the pillar on the right in the construction photo you have on your web site.

Cross bracing element showing turn buckle for stiffening.  Note also the ceiling hangers and attached blocks.  These days they use strapping rather than wire.  The also use gang nails rather than blocks as seen here.

Spacing blocks welded between cross member right angles.  Another indication that the architects and engineers were aware of the need to brace against lateral loads from seismic events.  The blocks multiply the resistance against bending.

These are the cross bracing connections at the bottom of the trusses.  The location of the cross braces also indicate the architect and engineers appreciation for earthquake strengthening.  These braces are more substantial than what is used for today's cross bracing to meet seismic building codes. Note the spacing of the ceiling joists and even the boards along the access ways are placed to exact measurement.  This is the sign of "A True Tradesmen" as they say in the Construction business.

This images shows how trusses rest on top of reinforced concrete beams and directly above reinforced concrete pillars.  This indicates the fact that the architect designed the building to withstand seismic events not just wind loads as implied by the Beca report.  The photo was taken in the ceiling cavity of the David O McKay Building.  The bottom of the trusses are attached to brackets with a loop connection to the inside of the pillars.

This is the bottom bracket.  The bracket is welded to the truss.  You can see from this image that the concrete is correctly compacted.

These are the roof rafters.  They have are massive measuring 4"x16" they support the 2"x6" sarking and the ceiling rafters between trusses by way of number 8 twisted wire.  (Now that part is very much a Kiwi tradition that is widely used in place of strapping, it allows the builders to adjust the ceiling height with simple turns of the twist thereby giving you a perfect ceiling.  These may have been added later.

Roof Leak due to poor maintenance

Winch for one of the basketball hoops.  Note the poor maintenance of ducting insulation.