In short: Drainage problems are the cheapest defects to fix and among the most expensive to ignore, because they feed every moisture problem that comes afterwards.
Ponding is a symptom
Water ponding in a silt pit means the pit is not draining, which means the system it feeds is blocked, undersized or falls the wrong way. It is visible on the day and easy to test, and it is the kind of thing that gets accepted at handover because it was dry when the inspection happened.
The ground against the slab
Once the landscaper arrives, ground levels change. Garden beds against the slab edge, paths that fall toward the house, and irrigation on one side only are all owner-created drainage problems that later present as slab movement and get blamed on the builder.
Check it in the rain if you can
The most useful drainage inspection happens while it is raining, or immediately after. Everything is obvious then and nearly nothing is obvious in dry weather.
Written by the Owner Inspections team from inspections carried out in Riverstone. Licensed building practitioners, NSW Fair Trading licence 366177C.
