How to Reduce Humidity in Your Home (and Stop Mould)

How do you reduce humidity in your home?

Lower the moisture going into the air and give it a way out. Run exhaust fans in the bathroom and kitchen, open windows on dry days, dry washing outside, and use a dehumidifier in damp rooms. Aim to keep indoor humidity below about 60%.

Why is my house so humid inside?

Everyday living adds water to the air. Showering, cooking, drying clothes indoors, and even breathing all release moisture. Newer homes are sealed tight to hold heat, so that moisture has nowhere to escape and settles on cool surfaces like windows and the corners of outside walls. In damp climates the outdoor air is humid too, which is why opening up helps most on drier days.

What actually lowers the moisture?

Start with the sources and the airflow, in this order:

• Fix leaks and rising damp first. A dripping pipe or a wall that wicks moisture will out-pace any fan.
• Run exhaust fans during and for ten minutes after every shower and while cooking, and check they vent outside, not into the roof.
• Dry washing outdoors where you can. A single load dried inside can release several litres of water into the air.
• Open windows on dry days to cross-ventilate, especially the bathroom, kitchen, and laundry.
• Use a dehumidifier in rooms that stay damp, and empty it regularly. Aim to keep humidity below about 60%.

How do I reduce humidity in a bedroom?

Bedrooms get humid overnight because a sleeping person breathes moisture into a closed room for hours. Crack a window or leave the door open for airflow, and open the curtains in the morning so surfaces can dry. Keep wet clothes and damp towels out, leave a small gap at the back of the wardrobe, and add a compact dehumidifier or a moisture absorber if condensation keeps forming on the glass.

How do I stop mould in a humid house?

Getting humidity down is the essential first step, and it lines up with Queensland Health advice to control moisture before anything else. There is an honest limit though. A moisture absorber lowers the humidity but does not neutralise the mould spores already drifting in the air, and a spray clears a surface stain while the airborne spores settle and re-seed it. That is why mould keeps coming back after bleach.

The step most people miss is treating the air itself. First Light is a natural airborne mould-prevention treatment dispersed by a waterless diffuser, so it works on the spores in the room rather than the stain on the wall. In lab testing it achieved a 99.2% reduction in black mould on direct contact, tested to BS EN 13697. Pair it with steady moisture control and you address both the damp and the spores that damp feeds. For the full routine, see how to actually stop mould coming back.

For the full picture, see our complete guide to stopping mould in Australian homes. See also stopping mould in a humid Queensland home.