‘Our houses are crumbling down around us’: Homeowners in Ireland protest against mica damage

The sound of a wall cracking in the middle of the night is not an uncommon experience for residents of Donegal county in northwestern Ireland. Homeowners in the area have come together to demand government redress for their homes that are falling apart. They were built by various companies in a period of rapid construction using rocks from nearby quarries that contain an excess of the mineral mica – which after several years cracks, crumbles and turns to dust. 

A home built with materials containing excess amounts of mica minerals crumbling in northwestern Ireland.
A home built with materials containing excess amounts of mica minerals crumbling in northwestern Ireland. © MicaRedress

Mica minerals, naturally occurring in rocks found in local quarries, have been found in excess quantities in the blocks used to build a number of homes in the area, and are blamed for defects in up to 7,000 homes, causing cracks and widespread damage. 

Homeowners have begun sharing photos and videos of their deteriorating homes to draw attention to their cause and elicit a government response.

A video shared on Twitter on November 16, 2021 shows the crumbling exterior wall of a mica-affected home.
Photos posted on Twitter on November 10, 2021 show a mica home covered in cracks.

‘You can be lying in bed at night and you’ll hear the walls crack’

Michael Doherty is the public relations officer for the Mica Action Group (MAG), which aims to garner government support for people to rebuild their homes. 

We have bits of walls falling off, and some houses have had to be evacuated because they're just no longer structurally safe to live in. In my house, I can dig with my hand right through the outer wall, through the insulation until I hit the hard plaster of the inside wall. That’s how weak the walls are. It’s actually very scary: you can be lying in bed at night and you’ll hear the walls crack. You just hope that it’s not somewhere near another crack, because if they join up you could have a catastrophic situation. Families have moved into just one or two rooms on the relatively safer side of their homes. If the right storm hits over Christmas time, we could have a house collapse, that’s our biggest fear at the moment. 

Irish law forbids using building materials with more than 1% mica present, but testing has revealed that some Donegal homes contain more than 15%. 

Most of these homes were built during Ireland’s Celtic Tiger years, a period of rapid economic growth from the mid-1990s to late 2000s. The construction industry was booming: at its peak, 90,000 homes were built in a year. To meet with this increased demand for construction, a number of companies started making construction materials using more than the allowed amount of mica.

While these blocks may have passed certain inspections at the time of manufacture, such as strength tests, the problem lies in their capacity to hold up over long periods of time and in various weather conditions. The mineral attracts moisture from the environment, impacting the strength of the blocks used to build homes and causing them to crack and crumble after around five years, according to an expert panel report published in 2017.

'There was no one there to regulate them because the authorities trusted the quarries to do the right thing'

Quarries struggled to provide for enough blocks, so they moved into areas of the quarry that had rock that was excessive in the mineral mica. There was no one there to regulate them because the authorities trusted the quarries to do the right thing. The problem with all this is you don’t see the problem right away. It takes five or six years before the problems come to the surface and it just gets worse with every year that goes past. 

MAG was created 10 years ago when Doherty and other homeowners began to notice cracks in their homes. They soon realised that the mineral was impacting thousands of households in the region, and decided to hold the government responsible for failing to enforce mica regulations. 

‘My daughter won’t sleep in her room anymore’

Donegal resident Paddy Diver has been at the forefront of a citizen movement to garner public attention, holding public protests and fundraising, after he realised mica was in the home he built for his family. 

I put it in the back of my mind, hoping I wasn’t one of those houses affected by mica. I’ve been working in construction since I was 16. I built the house ten years ago, but then about four years ago, those cracks started to appear and started to get wider and bigger. It’s like a cancer inside the block that comes out. Every year it got a little bit worse. Now I can pull away at the wall with my hand. 


A video posted on Twitter on October 28, 2021 shows activist Paddy Diver pulling chunks of concrete off a home affected by mica. The material crumbles into dust.

I think my house is safe for another year, maybe two. It’s heartbreaking. I reassure my children because I know the house is strong enough, but the cracks are terrifying. My daughter won’t sleep in her room anymore. We had to move her bed into our room because she’s 8 years of age and doesn’t feel safe unless I’m in the room. My older son was awake at 3 o’clock in the morning because he couldn’t sleep hearing the cracks.

Realising he needed to take the protest “to the streets”, Diver and thousands of other Donegal residents took a convoy of buses into Dublin in October to send a clear message to the Irish government. 

A video posted on Twitter shows Paddy Diver speaking to thousands of people protesting in Dublin for mica redress.

The government offered a redress scheme in 2020 where mica-affected homeowners could be reimbursed 90% of their rebuilding costs, but Diver and Doherty say that in reality, homeowners end up having to pay much more than is possible to fix their homes. In the end, they say that some homeowners would have to pay from 30 to 200 thousand euros out of pocket to repair the damages – on homes they’ve already taken out mortgages on. Homeowners also have to pay over 5,000 euros to test for mica before being eligible.

A video posted on Twitter on September 17, 2021 shows a worker drilling into a brick to test for mica.

The Mica Action Group has been lobbying authorities to pay for 100% of necessary costs for all affected homeowners, as well as organising an independent public inquiry into how the defective blocks were able to be manufactured – and make sure it doesn’t happen again.

On October 21, 2021, one building firm implicated in the scandal, Cassidy Brothers, was ordered to shut down one of its concrete plants. Cassidy Brothers, which was the largest block supplier in north Donegal county, said in a statement in 2018 that it manufactured products made using raw materials from various suppliers. Quarries themselves are now under scrutiny by the Irish attorney general.

Donegal county isn’t the only place in Ireland grappling with this type of problem – homes in Mayo and other nearby counties were also built with mica blocks. More than 10,000 homes across Ireland were also determined to be affected by a mineral called pyrite, which has equally damaging impacts. 

MAG and other campaigners will present their case to the European Parliament next month.