How to deal with mould in your home following rainy weather

Ignoring it is not an option, says specialist Steve Ashby

Mould inside the home can cause discolouration and disfiguration of walls, door frames and skirting boards. Sarah Maisey / The National

Like many others, my home was flooded in last month's storm and its aftermath, with a chance of recurrence if it pours again this week.

As the water rushed through the doors and leached up through the floor, my neighbours mobilised and we rushed from house to house hoisting expensive fridges, washing machines and dining tables on to bricks and out of harm's way.

After two days, we squeegeed the last of the water out of my house, and by day four the garden had absorbed the final pool of fetid water. All done, I thought.

And then the mould appeared.

Loitering in corners, inside cupboards and on the backs of bedside tables, mould spores are now thriving in my house, growing on the damp walls and furniture that sat waterlogged for two days. Although all doors and windows were flung wide open to help dry things out, unfortunately I had not realised that the warm, humid climate that affords us a lovely lifestyle most months of the year is also the perfect breeding ground for mould.

While not exactly a pleasant house guest, mould is a naturally occurring organism that is found across the planet, including in the ice-clad North and South poles. Approximately 1.5 billion years old, it plays a crucial role in the Earth’s ecosystem, recycling vital nutrients back into the environment by breaking down dead organic matter. Too small to be seen by the naked eye, mould only becomes visible when enough grows together to become a colony.

“Mould is all around us and it is part of the cycle of life,” says Steve Ashby, founder and managing director of Vivoteq, a specialist mould treatment company. Since they launched the company in 2009, Ashby and operations manager Mairi McKerr have successfully treated thousands of homes and 15,000 hotel rooms. In one of life's moments of happenstance, he is also my neighbour. “Mould is only a problem inside in our built environment because it does exactly what it would do on a rainy day outside – it thrives.”

The recent flooding, he explains, inadvertently created the perfect environment for mould. “It needs two things to survive – moisture and absence of light. From there, it will just take off and grow incredibly fast,” he explains.

“If water got in [to a house], people are likely to find mould behind skirting boards that are generally made of MDF, which gets wet and acts like a sponge.”

MDF, or medium-density fibre board, is a common material in modern UAE homes, used for door frames, cheap furniture and skirting boards. When these get wet, the surface will absorb water and begin to swell. In my house, this telltale ballooning can be seen on the legs and sides of my Scandinavian flat-pack furniture.

My first instinct was to rip out all the contaminated surfaces, drag them through the house and dump them in the garden. While understandable, Ashby explains, it is also the worse thing to do. “Mould sporulates, and gives off billions of spores to regenerate in as many places as possible.”

Having evolved to release spores into even the lightest of breezes, mould, when disturbed, sends spores skittling around our homes, looking for the next surface to land on. “Spores float in the air and land on other things that might be humid, such as clothes, shoes, furniture and handbags,” he explains.

In a bid to remove mould from one area, we risk spreading it further. Any skirting board or patch of wall that has swollen or become discoloured suggests mould might be present, and Ashby recommends isolating it as quickly as possible. “Get some plastic or even cling film, and tape it over the area,” he says. “Don’t take [the infected pieces] off, because the spores will go everywhere. If you tape it up, the mould will still be there, but it won't be going everywhere. And then you call a professional.”

Given the UAE's humid climate, it is imperative to not disregard mould, if discovered, says Ashby. “Even if you see a tiny bit, do not ignore it. It will not just go away by itself,” he says.

Steps to help contain mould

As a member of the fungi family, mould has two states: active and dormant. The active state is when it finds the right conditions and begins to grow. Dormant is when conditions are unfavourable, so it simply shuts down to wait until conditions are better. The recent wet weather has provided the ingredients for mould to be active, so drying furniture out will help return mould to its stable, dormant state.

Mould in the home also carries serious health implications, as all 150,000 species can trigger respiratory issues, headaches, congestion, sneezing, allergies and infections.

Some items, if handled carefully, can be sorted by the homeowner. Small furniture with mouldy patches, can be covered and removed. “Wrap that area in plastic then get it outside and let it dry. The humidity during the day is very low, about 30 per cent, and it will do a good job of reducing the mould back to its normal state. There are various products you can get that kill mould, so spray those on and let it dry. Then you can probably put the furniture back inside,” Ashby explains.

Examine clothes for small dots of white or green mould, and if spotted remove them to somewhere dryer. “Take all clothes out of the cupboard and hang them on free-standing rails where the humidity is low.” Clothes can then be machine-washed or dry-cleaned.

Buying a dehumidifier is crucial as it removes moisture from the room, while furniture must be pulled away from walls and put on bricks to aid air circulation. Floor coverings such as parquet, vinyl or rugs must be removed to dry the water trapped underneath.

When it's time to call in the professionals

Wet walls, however, are more serious, says Ashby. “If you have a wall that you think is getting wet, press against it and if it moves under just thumb pressure, you could have a problem.”

Be vigilant for a “damp, dank, earthy smell” and a deepening discolouration on the walls, as this points to mould growing on the other side. Once again, doing nothing is simply not an option. “After a week or two you will see the mould on the front [of the wall]. It travels through the gypsum,” Ashby explains.

In such cases, the wall panels will need to be removed, and it is important this is only tackled by people with experience. “The international protocols are to cut out the wall panel until you get 60cm above the infestation, in every direction. These are regulations that were propagated in the 1970s and good companies will know and adhere to that.”

When looking for a reputable company, Ashby suggests asking key questions. “Ask them what international standards they use, and if they can’t tell you, then stay away. Ask for references. Good companies will get a lot of their work by word of mouth. Ask what products they use. If they say bleach, walk away.”

While household bleach will kill surface mould, it will not tackle the root issue. Reputable companies instead should be using specialist compounds to deal with the problem in its entirety.

“The keywords to look for are quaternary ammonium salts, commonly known as quats. This is a long-tailed carbon chain molecule, and at Vivoteq we use a mixture of two quats as a very fine fog.”

Once introduced into the home, the molecules help suppress the mould. “When it tries to grow, it gets spiked by the long-tailed molecule that ruptures the membrane of the mould spore. Quats are essential, yet incredibly powerful. However, when used correctly, they are non-toxic.”

“When you start seeing spots on clothes, shoes or bags, call a professional company immediately. We only ever see five per cent of what's there; the rest of it is already on your personal belongings.”