Mould a Growing Problem in Iceland

Mould is a growing problem in Icelandic homes and buildings – and not only old ones. Recent reports indicate that the way insulation is installed in Iceland could be the root of the problem.

Icelandic media has increasingly reported on entire homes demolished and buildings, even government offices, closed due to mould infestation. RÚV spoke to Ríkharður Kristjánsson, engineer, about the issue on morning radio today. Ríkharður says mould growth can be traced back to the Icelandic practice of insulating homes and buildings from the inside rather than the outside.

In true Icelandic fashion, Ríkharður compares house insulation to sheep. “You can see how the sheep prepares itself for winter. She grows wool, which is insulation, and she has it on the outside, not the inside. We, when we go out into the cold, we also dress ourselves in wool clothing, and we put it on the outside. But when we insulate a house, we do it on the inside.”

Ríkharður says the reason for the practice is simple: weather conditions make it difficult to insulate buildings from the outside in Iceland. He adds that there was general ignorance about the issues that could arise when insulation is installed from the inside rather than the outside.

“One thing is that it can emit humidity, that’s just the physics. Another thing is that the outer walls become cold, the inner walls and panels hot and when they cool the outer walls contract. It’s like when a man puts on a sweater that’s too small. It splits at the seams.” The same physical phenomenon occurs in houses, Ríkharður says, forming cracks in its structure. In addition to inviting moisture damage, the cracks can affect sound isolation in large buildings – the walls vibrate and sound travels more between floors.

Ríkharður says that although it is more costly to insulate buildings from the outside, the practice is gaining traction in Iceland. He mentions the recently built Höfðatorg tower in Reykjavík as one example. He adds that Iceland needs to set more stringent regulations for construction that take the local weather into account, as general European standards are not sufficient. In the meantime, procedure seems to be slowly changing.