Cleaning in Parkdale & Mordialloc: Coastal Humidity, Salt Air and Mould

Clients along the foreshore in Parkdale, Mordialloc, Aspendale and Beaumaris describe the same three things. Towels take forever to dry. There's a spot in the wardrobe or behind the bedhead that keeps coming back. And metal fittings - shower rails, door handles, outdoor hardware - corrode faster than they should. All three come from the same source, and it's not a cleaning failure.

Why the bay changes the numbers

Two things happen close to the water. Ambient humidity runs higher and, more importantly, stays higher for longer stretches - so anything damp dries slower, and the moisture content of the air inside the house sits above what it would a few kilometres inland. And salt aerosol carries in off the bay, depositing a thin, hygroscopic film on glass, metal and external surfaces. Hygroscopic is the operative word: salt pulls moisture out of the air, so a salt film keeps a surface fractionally damper than a clean one.

Those numbers matter because the biology has thresholds:

• Dust mites absorb water from the air rather than drinking it, and they thrive above roughly 50% relative humidity. Below that they struggle to survive.
• Mould generally needs sustained surface humidity around 70% or higher. It doesn't need standing water - just a cool surface and air that's damp enough for long enough.

Which is why the mould in these homes shows up in exactly predictable places: the south-facing external wall, inside a wardrobe pushed flat against it, behind a bedhead, in the corner of a window reveal, and in bathrooms without a working extraction fan. Those are the coldest surfaces in the house, and cold surfaces are where warm humid air condenses.

How to treat mould properly - and why bleach isn't the answer

This is the most common mistake we see, and Victorian health guidance is clear on it. For mould on hard surfaces, a mild detergent solution or a diluted white vinegar solution, applied and then physically scrubbed off, is the recommended approach. Chlorine bleach is not recommended for general household mould: on porous materials like plaster, grout and timber it bleaches the colour out of the surface growth while leaving the structure below intact, so it looks fixed and returns. It also produces irritating fumes in exactly the small unventilated rooms where mould lives.

The other half is that mould on porous material that has grown into the substrate - soft plasterboard, swollen skirting, silicone that's blackened right through the bead - can't be cleaned. It has to be removed and replaced. Silicone in particular: once the growth is inside the bead, cutting it out and re-sealing is the only real fix, and it's a cheap job.

If the affected area is large - more than about a square metre - or there's a suspected leak behind it, that's a building and health issue rather than a cleaning one.

The habits that actually change the outcome

1. Get indoor humidity into the 30-50% range. A $20 hygrometer is the most useful thing you can buy for a coastal house - it turns guessing into measuring.
2. Run the bathroom fan during the shower and for 20 minutes after, with the door shut. If the fan vents into the roof space rather than outside, that's a real problem worth fixing.
3. Pull furniture 5cm off external walls. Wardrobes and bedheads flat against a cold south wall are the single most common mould site in these homes, because there's no air movement to carry moisture away.
4. Don't dry washing indoors without ventilation. A load of wet laundry releases litres of water into the air.
5. Wipe window reveals dry on cold mornings through winter. Two minutes, and it stops the seasonal mould line before it starts.
6. Rinse salt film off glass and external metal periodically with fresh water before cleaning - it stops smearing and slows corrosion.
7. Clean carpets more often than the general guidance. Every 6-9 months rather than 12-18 makes sense this close to the water, because damp carpet holds odour and supports dust mites far more readily.

The one that surprises people

Wardrobes. Closed, unventilated, against an external wall, packed with fabric that holds moisture - it's an ideal environment, and nobody looks in the back corner of one until something smells. Leave the doors open occasionally, keep the contents off the back wall, and check the corners each season. It's the cheapest mould prevention available in a bayside home.