Living in Pottsville only 20 minutes south of the Queensland border can present issues in regards air quality in the home. The heat, humidity, and the recent floods can cause problems with bacteria and mould.

In this high humidity environment any dust, dirt or organic matter can quickly turn into a food source for mould. You can almost see our bananas ripen on a hot day up here and to compound this problem many of our neighbours in the Tweed Coast, Murwillumbah and Lismore regions have experienced the worst flooding in decades.

Like many residents you may want to escape the hustle and bustle of the Gold Coast, preferring the space and privacy of a ‘tree change’ but unfortunately most houses don’t measure up when it comes to preventing mould and bacteria.

A key to a low-maintenance healthy home is the use of single-skinned building materials that are waterproof, thermally insulating and resistant to mould. An additional benefit is that the extra cost involved in this method of construction is offset by the durability of these materials. Having resistance to damp and mould isn’t only good for your health but it is also good for the structural integrity of your home!
Also ventilation inside and outside all the surfaces of the house is vital, in fact rising damp in a building can be fixed by just improving the ventilation underneath the house.


The first cardinal sin that is made is often poorly maintained carpet. How many people actually get their carpet dry cleaned regularly? How many carpets go without vacuuming for far too long? It would seem crazy to wear a jumper over and over perhaps dusting it off now and then without washing it. In the same way steam-cleaning carpet is a must and it may need it more often than you think. Even so, carpet comes in more than one layer, do you think that an underlay will stay clean and mould free over its lifetime of 10 – 30 years?

The worst carpet problem I have seen is at house in Moe an hour and a half east of Melbourne. Cat lady + carpet in the kitchen + no cleaning… Time to get out the anti-radioactive bio-suits!

In light of this many people have chosen other types of flooring and with proper care and maintenance they can be kept relatively mould free. For example there are anti-mould finishes on timber flooring, and anti-mould grout for tiled flooring. But in the long-term these two surfaces may still end up harboring harmful allergens.

More recently there has been the trend to use polished concrete floors for a modern, industrial look. You would think that you would be able to pour concrete and polish the top and you will never have mould coming through your floor. Unfortunately it isn’t that easy. As concrete is porous, rising damp (capillary action) will create an environment susceptible to mould.

One answer to this problem is with the use of a suspended concrete slab. For structural purposes a layer of plywood (or equivalent floor sheeting) will need to be placed underneath the slab to prevent it from cracking.

Marine ply is a good option for water resistance. Although even the highest grade marine ply will become subject to water and mould damage without protection. A waterproof membrane applied to both sides of the marine ply will create a waterproof non-porous surface that won’t allow moisture to penetrate. If the membrane that is exposed to the weather is re-applied every 5 years or so the membrane will become ‘sacrificial’ meaning the plywood will be preserved while the membrane that is attacked by the weather is re-applied as it deteriorates.

Not only can polished concrete flooring be used throughout the house it can also be used in wet areas like bathrooms and laundries that may otherwise become moldy. It is important that a high quality finish is used on the polished concrete surface and to maintain the surface a coat of wax every 3-9 months will prevent damage.


As with flooring single-skinned waterproof materials are the best option in humid areas. Perhaps thick stainless steel would be the best anti-mould, low maintenance, and thermal efficient option for walls, floors and for roofing. Unfortunately the price tag would mean that only the extremely rich could afford it.

From a more practical perspective a brick house with occasional maintenance can be a good alternative. This is a step-by-step guide to anti-mould brick walls

1. Ask the bricklayers if they mind putting an anti-mould additive into the mortar, ignore their assurance that “she’ll be right” without it.
2. When the walls are built apply penetrating waterproof sealant to both sides of the brickwork. This will help make the bricks waterproof as it fills all the microscopic holes in the brickwork.
3. Internal walls including interior walls can be flat rendered to decrease dust settling with a quality anti-mould additive.

A good option for wet area walls is tiles. Good quality anti-mould grout is recommended along with regular cleaning. If you have the money a complete wet area refurb every 5 to 10 years is a good idea because mould growth will invariably get into those hard/impossible to clean corners.


At the start of the article I mentioned that this was my kind of anti-allergy dream house. Move over Barbie all the kids will want my bland sparsely decorated anti-allergy model houses the world over! I guess this is where it gets a little more dreamy…

Call me obsessive but the idea of a roof cavity full of dust hanging over my head doesn’t really sit well with me. Is that dust coming back down through vents? Probably. Perhaps the dust comes out the outside of the roof around the eaves and gutters ending up back inside the house?

So the concept of a livable space in an attic is a good way to cut costs, maximize space and potentially reduce dust.

Using paint on a corrugated iron roof is a good option. This paint will reflect the heat from the sun instead of it being absorbed into your living space and it also contains anti-fungal and anti-mould properties.

In this dream house the attic/top floor ceiling will follow the roofing sheets at the same pitch only separated by the roof joists. I would use fiberglass insulation in the roof for its resistance to mould and use an anti-mould paint on mould resistant drywall ceiling sheets.

Have a look at the next article on anti-pollen, anti-dust fly screens, thanks for reading ☺