Box gutters at lock-up on contemporary Castle Hill rebuilds
Joints, upturns and sumps, checked while they can still be changed.
In short: A Castle Hill lock-up inspection in March 2025 recorded a box gutter without an expansion joint, an upturn not properly formed and a sump that changed direction.
Why box gutters fail
A box gutter sits inside the roof footprint. When it overflows or leaks, the water ends up inside the house.
Expansion joints
Long runs of metal gutter expand and contract. Without an expansion joint the seams work loose.
Upturns
The gutter edge against a wall needs a proper upturn so water cannot ride up and over it.
Sumps
The sump should discharge straight down to the outlet. A sump that turns the water slows it and invites overflow.
Book lock-up for these designs
Once ceilings go in, box gutter faults show up only as stains.
Written by our local inspection team from work carried out in Castle Hill. Licensed building practitioners, NSW Fair Trading licence 366177C.
