ᐅ Increased Fire Risk Associated with Polystyrene Insulation

I had my house insulated with an external thermal insulation composite system (ETICS) using expanded polystyrene (EPS) and have now heard with concern about the increased fire risk. This material acts like an accelerant, and it’s unbelievable that such an insulation product received approval. Is there a way to make an existing polystyrene insulation more fire-resistant?

Only insulation materials that are not easily flammable may be used. Additionally, a house typically burns from the inside out – combustible insulation on the outside of a wall becomes problematic if heated insulation drips down over a window that is intended as an escape route. For this reason, it is recommended to insulate the lintel area above windows with mineral wool.

In a single-family house, the escape route issue is less critical, as there are usually multiple escape options available.

In any case, you cannot make polystyrene insulation more fire-resistant.

You cannot verify this afterward; the contractor’s invoice may state that mineral wool lintel insulation was charged, but whether it was actually installed cannot be determined once the plaster has been applied.

The topic is currently gaining a lot of attention in the media. The federal state of Hesse intends to bring the fire performance of exterior wall insulation made of polystyrene to the agenda of the Building Ministers' Conference.