In short: A porch roof weighs very little, which is exactly the problem. Uplift, not gravity, is what its fixings are there to resist.
Uplift is the load that matters
People look at a porch post and think about the weight above it. The engineering is thinking about wind getting underneath a light roof and lifting it. Skew nailing holds a post in place against gravity and very little else.
Why it passes a glance
A skew nailed post is upright, fixed and looks finished. Nothing about it appears wrong until the day it is asked to resist uplift, which may be years away and will be during the worst weather that site has seen.
Checked at frame, fixed in minutes
Proper tie down hardware costs a few dollars. Installed at frame stage it takes minutes. Retrofitted after the porch is finished and lined it means undoing finished work.
Written by the Owner Inspections team from inspections carried out in Donnybrook. Licensed building practitioners, Building & Plumbing Commission registration CDB-U 53425.
