Practical Engineering: Building Strong Garage Door
Walls, continued
Follow the Recommendations
Before using this technique on a job, take time to study the
APA's literature, available free online at
www.apawood.org/bracing. This document
suggests that the Narrow Wall Bracing Method should be:
• used next to garage doors only
• applied only to the first story of residences up to two
stories
• used only on structures that are entirely sheathed
• used only in Seismic Design Categories A through C
And as you might expect, you should always confirm that the
codes and inspectors who govern your area have no problems with
the APA system.
Practical Considerations
As a builder, I feel the trickiest aspect of the APA method is
the fussy placement of the anchor bolts. Most of the foundation
subs I've worked with would likely have difficulty grasping the
importance of accurately placing the bolts: If they're 3/4 inch
off, you may not be able to install the plate washers. My
strategy is to highlight the bolt placement details on the copy
of the plans I give the sub, and to remind him that the amount
of his final payment is directly tied to accurate anchor bolt
placement. Retrofitting a botched bolt placement would be time
consuming and expensive.
The restriction on sheathing penetrations is also problematic
from a supervisor's standpoint: I've got to make sure everybody
on the site knows not to mess with the narrow-wall sheathing.
My approach? Spray paint "NO HOLES" on the sheathing and the
housewrap as they're installed. It's a good idea to explain the
same thing to the homeowners, so they don't later decide to put
a pet door in the wall. I also document this restriction.
Contributing editorCarl Hagstromis a builder in Montrose, Pa., and
presents structural clinics at JLC Live.