Farm buildings and homes in Co Donegal are “crumbling” as a result of defective blocks used in their construction, after the mineral muscovite mica was discovered in the blocks a number of years ago.

Irish Natura and Hill Farmers Association (INHFA) spokesperson Henry O’Donnell said: “A large number of houses and farm buildings are now crumbling, leaving their owners facing the prospect of a huge repair bill due to the inadequacies of the current redress scheme.

“I would have built a couple of farm buildings around 2007 when there was a rush on the TAMS scheme. The buildings are made of structural steel but the walls were built with the blocks. There’s deterioration in them, with some crumbling, but it was built to TAMS specification,” he said.

O’Donnell’s house also needs to be demolished and rebuilt. He added that once redress for householders is sorted out that there should be redress for farm buildings too.

Mica in concrete blocks has resulted in some farm buildings on Jimmy Mooney's pig farm in Co Donegal cracking and crumbling. \ Jimmy Mooney

Another farmer, Jimmy Mooney from Malin Head, keeps 600 sows and his farm buildings and his home are affected by mica.

“The way pigs work, we have different units and houses. I’ve knocked and rebuilt one and I’ve various others to be knocked. It’s a wild setback. I can see from other farm buildings how bad the blocks are, I don’t think anyone appreciates how bad blocks are,” he said.

“I’ve got 27 pens to knock and it will cost €5,000 per pen. It’s multiples of that,” he said.

Mooney told the Irish Farmers Journal that he wants people’s homes affected by mica to be sorted out first and that nobody should be out of pocket.

“There are some horror stories up here. Farm buildings will need to be looked at at some stage but homeowners need to be supported first.”