Which material is suitable for blown-in insulation? - Experiences?

Hi, I requested a quote for blown-in insulation, and I was asked which material I prefer. Styrofoam beads, glass wool, or stone wool.

Does anyone have experience with this? Are the advantages of stone wool worth the approximately 30% extra cost? My cavity is about 9 cm.

Thanks

Rock wool has a higher density and, as a result, somewhat better sound insulation and heat protection. It is also a bit more heat-resistant. However, this can be disadvantageous with blown-in insulation. On average, the thermal insulation is somewhat worse. With blown-in insulation and such a large price difference, I would probably go for glass wool.

Thank you, I was also leaning in that direction.

Morning, I got a quote for blown-in insulation, and they asked me which material I prefer. [...] My cavity is about 9 cm.

We don’t know your house. A 9 cm thick air gap is very unusual; you should explain that in more detail. Most providers of blown-in insulation are purely sellers of their (non-certified) combination of trade and service, have no idea, and don’t offer any other options. Consequently, their only argument is the ratio of price to expected benefit. Apart from the fact that you might be surprised how many cubic meters of whatever can fit into your cavity, you should discuss the measure with a neutral, competent expert. In my mind’s eye, an Albanian roof window replacement mafioso is currently blowing globules into your cavity.

Hi, this is already a larger local company, so I have fewer concerns in that regard. I was present during the drilling and can understand how it was determined. How can I further explain the large cavity?

Moin, this is already a larger local company, so I have fewer concerns in that regard. I was present during the drillings and can understand how it was determined.

I recommend my advisees never rely on the "therapy proposal" of a provider, but rather have a methodically neutral expert evaluate which approach is most suitable for the specific modernization/renovation project.

How can I further explain the large cavity?

I would always consult the building file for this, compare the plan and the execution at that time, and discuss and plan the entire package of measures with an architect experienced in building renovations. Contracts based on estimates and billing based on measurements are the biggest cost traps in such projects.