ISO-STRAW 18 kg Bag – Floor Fill Insulation for Wooden Beam Ceilings and Cavity Filling
Blown-in Insulation for Roof, Wall and Ceiling made from 100% Wheat Straw
ISO-STRAW is a blown-in insulation made from unbound chopped straw, produced from 100% regional wheat straw, untreated and free from additives. With the European Technical Assessment ETA-24/0228, ISO-STRAW is approved as an official construction product across Europe. It is especially popular as a floor fill insulation or ceiling cavity filling (e.g. in wooden beam ceilings), as the high installation density not only provides excellent insulation but also significantly improves sound insulation.
Why ISO-STRAW as Floor Fill Insulation?
- Strong sound insulation through mass: approx. 85 kg/m³ installation density for floor fill, commonly used in intermediate ceilings.
- Settlement-safe in ceilings: tested settlement behavior in cavities sv = −0.5% (up to d = 330 mm).
- Summer heat protection: high heat storage capacity (c = 2100 J/kgK) effectively reduces temperature peaks.
- Vapor permeable: water vapor diffusion resistance μ = 2.8, supports balanced moisture regulation.
Composition and Environmental Compatibility
- Composition: 100% wheat straw (unbound chopped straw), free from additives, untreated.
- Free from harmful substances (REACH 1907/2006/EC): biocides = 0%, boron compounds = 0%, SVHC = 0%.
- Climate-friendly: processed ISO-STRAW permanently binds 1.4 kg CO₂ per 1 kg of straw.
- Resource-efficient: straw is an agricultural by-product, no additional crop land required.
- Packaging and recycling: vacuum-packed bags, return via processors possible, pure material recycling to reduce packaging CO₂ footprint.
Professional Application Note
ISO-STRAW can be applied manually in ceilings or installed using suitable blowing machines. Proper compaction is essential, especially in roofs, walls, and ceilings, to ensure settlement stability. ISO-STRAW is also used as loose fill in floor constructions.
Technical Data (Excerpt)
| Product type | Blown-in insulation made from unbound chopped straw (thermal and acoustic insulation) |
| Approval | ETA-24/0228 (EAD 0401387-01-1201) |
| Fiber geometry | Length approx. 30 mm, width approx. 5 mm |
| Fine fraction < 1 mm | 5–15% (approx. 10%) |
| Bulk density (installed) | 85–115 kg/m³ |
| Specific heat capacity | c = 2100 J/kgK |
| Declared thermal conductivity | λD = 0.042 W/mK |
| Design thermal conductivity | λB = 0.047 W/mK |
| Fire behavior | Class E (EN 13501-1) |
| Resistance to biological attack | 2 (normal) |
| Water vapor diffusion resistance | μ = 2.8 |
| Water absorption (short-term) | Wp = 15.96 kg/m² |
| Corrosion potential | none |
| Airflow resistance | r = 15 kPa·s/m² |
| Settlement behavior (cyclic temp./humidity) | SH 0, no measurable settlement (≤ 1%) |
| Settlement in ceiling cavities | sv = −0.5% (max. d = 330 mm) |
| Settlement in walls/rafters | sd = 0%, SC0 (max. d = 240 mm) |
| Packaging unit | Bag 18 kg |
Download
ISO-STRAW brochure PDF
ISO-STRAW data sheet PDF
