ᐅ Removed Roof Insulation – Possible Causes?

Today, I went up to the attic of my house to install a satellite dish and was shocked by the condition of the roof insulation. Several insulation mats had holes with pieces of mineral wool hanging out. It looked as if an animal had been rummaging around up there. What could this be, and how can I stop it?

It is questionable whether there was an animal there; mineral fibers are not suitable food for any animal. However, it is possible that an animal might have spent the winter in the fibers. In that case, I wonder if you would notice anything in the attic.
Look for signs such as droppings, tracks, or food storage... If you find anything, you can search the internet for the corresponding animal, including possible deterrent methods.

Hello Olli, what you’re describing is something I know from personal experience. You most likely have a marten on your roof. These animals tend to bite into the insulation just for fun and will eventually cause a lot of damage. You absolutely need to close all roof hatches and make sure that your roof is properly sealed where it meets the exterior wall. Martens use the smallest gaps to get into the attic. Once you have sealed everything, the problem will resolve on its own.

If martens have nested in a roof, the holes or tunnels apparently serve as access routes.
However, holes in the insulation are only an indication that martens might be present in the roof; since martens eat their prey inside the den, you would also expect to find feeding remains, odor, droppings, or urine stains. I think that would have been the first thing Olli would have noticed—especially the smell.
As mentioned before, just look for signs.