Mould loves Ireland’s damp climate – what can you do to fight its spread?

Damp and mould often seem to appear out of nowhere, and expand with almost wild abandon across walls and ceilings

We don’t live in the driest or warmest of climates, and although the rain is wonderful for our gardens, a combination of damp air and closed windows can cause problems in the home. Damp and mould often seem to appear out of nowhere, and spread with almost wild abandon across walls and ceilings.

Helen Riordan knows exactly what this is like, as she noticed some black spots on her bathroom wall before Christmas and with “a million other things to do”, ignored them as she carried on with her busy working life. But she says that it wasn’t until she had friends coming to stay last month that she realised that the spots had multiplied and were not only on the bathroom ceiling, but also in her spare bedroom.

“I’m not great for ventilation as I tend to get cold quite easily, so I have the windows closed a lot,” she says. “I hadn’t used the spare room for a while and it was only when I went in there to make the bed up for a friend that I realised that there were black spots all over the wall by the window and also on the ceiling. And the spots which had been in a corner of the shower, had also spread in the bathroom.

“I was in a bit of a panic as I have a busy job and don’t have time to do much housekeeping, so I got some cleaning stuff from the supermarket and spent an evening scrubbing, but while it reduced the spots somewhat, they are still visible if you know what you are looking for. I have tried to hide them in the bedroom with books on the windowsill, and in the bathroom, I’ve put toiletries in front of them – it’s not a permanent solution, but as soon as I have a few days off, I will do a proper job of it.”


However, this may not be the best way to deal with mould, according to Deirdre Farrelly of, who says it is a fungus, which can spread quickly if agitated.

“Unfortunately, our climate is generally damp, so we must try to stay ahead of it in our homes,” she says. “Mould spores become airborne and leave a musty odour in the room, so it is important to have it treated properly and professionally. There are many reasons it can form, which include building defects, insulation or ventilation issues and problems with heating. If the mould is from an obvious building defect such as water ingress, then it’s time to call in an expert as in many cases it just takes some simple practical solutions to help prevent it forming.”

Indeed, the Dublin-based expert says that there are many ways in which we can minimise the spread of mould in our homes.

“Firstly, all bathrooms should have strong extractor fans, ducted out to the exterior, normally via the eaves,” she says. “And as they don’t last forever, they should probably be upgraded every five to eight years. They can easily be replaced with the latest unit which would have faster and more powerful moisture extraction rates.

In the bedroom, she says that, where possible, it is never good practice to have your bed near an external wall as people naturally create moisture and condensation while they sleep.

“This will land and build up on the coldest spot in the room – usually the external walls – and this will turn to mould and may spread from there. Also, try to keep wardrobes away from external walls and when storing clothing in wardrobes it is a good idea to make sure coats, jackets, shoes and laundered clothes are dry and don’t over-clutter your wardrobe as there needs to be an air flow.”

This is important throughout the house and Farrelly says that both heating and proper ventilation can help prevent mould.

“During colder months, it is important to ensure the room has an ambient heat source every day, so turning the heat off will lead to problems,” she says. “Walls, furnishings, and personal belongings will get damp and mouldy – but even if the heat is kept on low, this will benefit the fabric of the building.”

Opening the curtains, blinds and windows every morning is also important, says Farrelly, as this helps to dissipate any build-up of moisture overnight.

“Even in colder months, it is good practice to do this for ten minutes or so while getting ready in the morning and if possible, try to create cross-ventilation by opening all the windows and doors upstairs. And all bedrooms should have passive vents fitted (cored hole), as this allows air to circulate 24 hours a day without having to worry about it – but this should not be the only source of ventilation as it is still beneficial to open windows every day.”

Finally, she suggests that attic insulation should be checked at least once a year for wear and tear, as it can shrink or move over time due to storing and moving things about.

“So attics should be fitted with roof vent tiles – a typical three-bed house will have six, three on the front and three to the back.”

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