Canadian Wood Council’s ENGINEERING GUIDE FOR WOOD FRAME CONSTRUCTION 2009
Received my ordered copy of this guide today. I took a cursory look this evening and not liking what I see. The critical difference between it and the guidelines in 9.23.13 in the building code is the minimum size of braced wall panels.
9.23.13 has a min requirement of 30″ braced wall panels (sheathed panels the full height of the wall) unless you are at the end of a band in which case you are allowed a 24″ panel if it connects in with a perpendicular panel 24″ or larger.
Part C of the Guide has a min panel length of 48″ and does not differentiate if at the end of a band and supported by a perpendicular panel. However, it then has a ‘Alternative Procedure for Narrow Braced Wall Panels – Table C2″ that allows you to reduce the min panel length to the height of the wall/3.5. So a 9ft wall falls under the 3.1m table column requiring a min 34″ panel length (still much larger than the corner panels and a bit bigger than the intermediate panels required by 9.23.13). But in order to get these narrower panels, you need to increase the total percentage of your braced wall band that must contain full height panels.
As I designed around 9.23.13, and was very close on some bands, the Municipal policies forcing me to instead design under the Canadian Wood Council Guide is going to force a redesign of my door and window placement on some walls. I just hope the design can accommodate these changes without significant rework.
The other option is a structure designed 100% to Part 4. This is what I was dreading and will avoid at all costs. Part 4 designed structures result in added build complexity and significant added cost to cover all the additional hardware required.
I have to say, I am extremely annoyed that the Municipality did not provide a heads-up much earlier in the process. The changes to Part 9 including the new 9.23.13 have been known by the Municipalities for well over a year, there is no reason the Municipality new resulting policies should not have been part of the permit package I received in March of 2013. I understand mistakes happen, and I hope they are now very vocal with any builders approaching them now and have this policy plastered all over the front desk, but this over-site sure has wasted a lot of my time and money.