What type of insulation is this?

[Emelie Axelsson1]

Opened up the outer wall to install a patio door and can't recognize what type of insulation material has been used, see picture. Does anyone know what it is and if it's common? Looks like paper and cardboard

 

[epw]

It looks like it could be some kind of wind barrier and not insulation.

 

[Vante]

Looks like the insulation in our summer house (an Anebyhus from the 50-60s.), some sort of asphalt impregnated cardboard.

 

[cpalm]

some sort of asphalt-impregnated cardboard.

Yep, Wellit.
I have it in a couple of places too. Seems to be a good material in that it has a decent lambda value, stays fresh over time, and doesn't cause any moisture problems or the like. However, flammability is mentioned as a disadvantage.