QUESTION: (SUMMER2014) I am involved with evaluation of an existing building structure for compliance with the current code. The structure is in a sound condition. It satisfies the building code and CSA S16-09 for the intended occupancy except that the column bases have 2 anchor rods instead of 4. In one area, a row of small wide-flange columns sit on a concrete wall. The x-axis of these columns, their anchor rods and the centre line of the wall all lie in the same plane. It is impossible to install 4 anchor rods in the normal configuration to this relatively thin wall. However, I can provide 4 collinear rods per column by adding 2 more. Is this collinear pattern acceptable?

ANSWER: I see two parts in your question:

a) Is collinear distribution of 4 anchor rods in compliance with Clause 25.2 of S16? The requirement for a minimum of 4 anchor rods aims to ensure erection safety. The rods should be positioned to provide an adequate lever arm against overturning in more than one direction. Clause 25.2 of S16-14 specifies 4 non-collinear rods per column, unless special precautions are taken.

b) Does Clause 25.2 apply to a structure that has been completed and in service? No, it is an erection safety requirement.