Obstructed Sub-Floor Vents and Limited Ventilation
Obstructed Sub-Floor Vents and Limited Ventilation is a moderate-severity drainage defect SURE inspectors have documented across 3 inspection reports.
Causes
- Accumulation of soil/vegetation/debris
- inadequate design
- Overgrown vegetation
- accumulated soil
- debris
Symptoms to look for
- limited subfloor ventilation
- restricted ventilation
- Vents covered
- Vents covered by soil/vegetation/debris
- concealed termite entry
Remedies
- Engage a landscaper or handyman to remove vegetation and/or lower soil level to clear vents
- Engage a builder to make improvements to the ventilation
- Engage a landscaper or handyman to remove vegetation and/or lower the soil level so that sub-floor vents are unobstructed and allow free-flowing air.
Worth asking our inspector about this specifically.
This is common across Perth stock and usually fixable without drama, but the scope of the fix varies. Every SURE inspection includes 12 months of free advice. Call out the defect by name and we check for it directly.
Curated entries in Drainage
- Curated 1–4/5Undrained Air Conditioner Overflow
Split-system and ducted air conditioners produce condensate that must be piped away from the building. Where the overflow line terminates against the wall or discharges onto soil at the perimeter, repeated wetting creates conducive conditions for subfloor moisture, termite activity, and rising damp in adjacent masonry or framing.
- Curated 1–4/5Inadequate Surface Water Drainage
Where surface water cannot drain freely away from the building perimeter, it accumulates against footings and walls, creating persistent soil moisture that is a primary conducive condition for termite activity and footing movement. The BCA requires finished ground levels to fall away from the building at a minimum 1:100 grade for at least 1 metre at every external wall.
- Curated 1–4/5Downpipes Not Connected to Storm Water
One or more downpipes discharge directly onto the ground at the building perimeter rather than into a stormwater system. Water concentrates against footings, raising the risk of footing movement, rising damp, and termite conducive conditions - we find this in 22.1% of all Perth inspection reports.
- Curated 1–3/5Debris in Gutters
Leaf litter, dirt, and organic matter accumulating in gutters blocks downpipes and causes water to back up, overflow, and saturate fascia and eave linings. We see this in 17.5% of all Perth inspection reports - one of the most frequent maintenance defects on the books.
- Curated 1–3/5Uneven Pathways
Differential settlement of concrete or paved pathways creates raised or sunken sections that direct surface water toward the building rather than away from it. Our inspectors record this in 7.86% of all Perth reports. Beyond water ponding and potential moisture ingress at the perimeter, uneven surfaces present a trip-hazard that may engage liability considerations for vendors and landlords.
- Curated 2–4/5Stormwater Drainage Directed Towards Building
Site grading or paving directing stormwater runoff towards the building foundation rather than away from it. Causes subfloor moisture accumulation, rising damp, and potential foundation movement on reactive soils.