Bracing a tall house on a narrow lot
Tie downs and strap bracing carry the wind load in a double storey.
In short: Strap bracing not hooped over the plate, recorded at a frame inspection in Ermington.
Why height changes things
A double storey on a narrow lot catches more wind for its footprint than a wide single storey. Fewer, taller walls have to resist it, so each bracing wall works harder.
Straps and plates
Metal strap bracing works by tension. AS 1684 requires the strap to be hooped over the top plate and nailed there, so the load reaches the frame.
What was recorded
At an Ermington frame inspection, strap bracing had not been hooped over the plate. A North Rocks frame had extra fixings needed around a void.
The bolt at the bottom
Bracing walls are held down to the slab with tie down bolts at set positions on the engineering. A wall missing one depends on nails it was never designed to rely on.
Checking it
All of this is visible at frame stage and hidden once wrap and plaster go on.
Written by our local inspection team from work carried out in Tallawong. Licensed building practitioners, NSW Fair Trading licence 366177C.
