Physical and mechanical properties of low-density insulating particleboards (0.45 g/cm3) made from wood chips and waste sunflower stalk (SFS) were studied, and correlations with the acoustic properties were determined. Two types of layered boards were manufactured, one with SFS in the central section, and the other with SFS on the surface layers; the layered boards were then compared with two kinds of homogeneous boards made from 100 % SFS and wood chips. Two types of resin were used, urea–formaldehyde (UF) and isocyanate; the press time was 5 and 7 min. Results showed that higher compression ratio in boards containing sunflower stalk resulted in significant improvement of physical–mechanical properties. Interaction between different layers of wood chips and sunflower stalk caused no clear trend in the acoustic properties of the layered boards with none of the resins; however, significant difference was found in the homogeneous boards produced with UF and isocyanate resins. High significant correlations were found between modulus of rupture and elasticity and thickness swelling (24 h) versus six acoustic properties. It can therefore be concluded that acoustic properties, as non-destructive tests, can be used to estimate some of the physical–mechanical properties of new insulating particleboards with different density and compositions.