Hello Klaus,
we are planning a single-family house KFW70 approx. 140sqm without a basement. Various construction companies have made us an offer and now we are unsure which material we should use as roof insulation for the exposed roof structure. The options are Styrofoam or blown-in insulation isofloc. Which material would you use and why?!
Neither...
Mineral wool has very positive insulation and processing properties, is resistant to moisture and aging, and also meets fire protection requirements. Its production is not very sustainable, but the energy balance is positive after a short time. Health risks are minimized by strict legal regulations and wearing protective work clothing.
Properties:
Mineral wool is an insulating material with very low thermal conductivity. With sufficiently thick thermal insulation, the energy demand of a building – heating in winter or cooling in summer – can be significantly reduced.
Mineral wool is easy to work with and is characterized by good material properties and diverse applications. It protects against heat and cold, insulates sound, and is resistant to mold, rot, and pests. Compared to other insulation materials, mineral wool is aging-resistant and relatively economical and easy to handle.
Rock wool additionally offers good fire protection, as it has a high melting point, is non-combustible, and does not release toxic smoke gases. Since the melting of glass wool in the event of a fire can have a significant impact, for example, on load-bearing capacity, rock wool is often necessary in structural verifications.
The environmental balance of mineral wool is not optimal due to its nearly non-renewable material base, the generation of fiber dust during processing, and its poor recyclability. The production of rock wool also requires a lot of energy (high melting temperature). In addition, the high bulk density of rock wool results in a higher dead weight of the entire construction (roof, wall) and disadvantages in transport. Nevertheless, mineral wool has a positive energy and emissions balance. After a few months, the energy required for production is compensated by its use as thermal insulation; the energy balance is balanced after a few weeks.
.... continuation on the page of DENA
Source: German Energy Agency
Best regards