These three suburbs grow mould faster than anywhere else on our run. Steep treed blocks, deep gullies and shade that holds moisture until mid-morning — it is a near-perfect environment for it, and it is why so much of our work out here is mould rather than dirt.
It is not your render and it is not your paint. It is the microclimate. The western suburbs sit in folded, hilly country with a lot of retained tree cover, and a house tucked into a gully or backing onto bushland simply does not get the hours of direct sun that burns moisture off a wall. Overnight dew sits until late morning. The south and south-east walls barely dry at all through the wet months.
Mould does not need dirt to grow. It needs moisture, shade and something to sit on, and a painted or rendered wall gives it all three. That is why a house out here can be cleaned, look immaculate, and be visibly patchy again in eighteen months while an identical house on a sunny Sunnybank block still looks fine after five years. Nobody did anything wrong — the conditions are just different.
Which means the method matters more than the pressure. Soft washing kills the growth chemically and removes it. High-pressure blasting knocks the visible top layer off, leaves the root structure in the surface and lets it come back faster — while also damaging the render. If the same wall keeps going green, that is very likely what has been happening to it.
Roofs follow the same pattern. Under tree cover, lichen gets into the surface of concrete tiles years earlier than it does out in the open, and the shaded half of the roof is always noticeably worse than the sunny half.
No high pressure anywhere near this. Pressure would have taken the render with it.
Mould on an exterior wall turns up in routine inspection reports constantly out here, and it lands on a property manager’s desk as a maintenance item. We do a steady amount of that work, and we make it easy: we deal with the tenant directly about access, we photograph before and after, and we invoice the agency rather than chasing anybody.
What we will also do is tell you when a wall does not need us. Some marking is staining in the paint rather than live growth, and washing it will not change it. Repainting is the honest answer in those cases and we would rather say so than bill for a job that will not satisfy the report.
For end-of-lease and pre-listing work, the useful combination is usually a soft wash of the affected walls, a driveway and path clean, and gutters cleared — the three things that show in an inspection and in the photos.
Also working nearby: Graceville, Chelmer and Moorooka.
