Abstract
<title>Abstract</title> <p>Forestry and woodworking residues were utilized to produce fiberized thermal insulation materials without the addition of binders or preservatives. Poplar bark, poplar sawdust (Populus euramericana), and forest residues collected from undergrowth were fiberized and used to fabricate cured, rigid insulation panels. The densities of the forest residue, bark, and sawdust samples were 172 kg/m³, 217 kg/m³, and 232 kg/m³, respectively, while the density of the control sample, made from solid pine wood, was 520 kg/m³. Biodegradation tests were conducted to assess surface staining and mass loss in the samples. All experimental samples exhibited significantly better resistance to surface staining than the solid wood control material. After a two-month testing period, the bark samples performed the best, experienced a mass loss of 15%, which was less than one-third of the mass loss observed in the other sample types. The study highlights that natural insulation materials, especially those made from bark, exhibit promising resistance to fungal growth and decay, suggesting their potential for sustainable and durable insulation solutions. The bark's inherent properties, such as its ability to protect timber against biological and mechanical damage, contribute to the effectiveness of insulation material.</p>