A barrier that stopped at the slab edge
One continuous layer, or no layer at all.
In short: Barrier not carried beneath the whole slab, and punctures left untaped.
What it does
Separates the slab from ground moisture, and performs only as one unbroken layer beneath the entire pour.
What we recorded
On one Marsden Park job the barrier did not extend beneath the whole slab. On another, punctures were left unsealed.
Why both amount to the same thing
A gap at the edge and an untaped puncture are each an opening in a layer whose function is continuity.
What follows
Moisture into the slab, typically showing much later as flooring lifting or persistent damp at the edges.
The fix
Extend the sheet, lap it correctly, tape the punctures. Minutes of work the day before the pour.
Written by the Owner Inspections team from inspections carried out in Marsden Park. Licensed building practitioners, NSW Fair Trading licence 366177C.
