Thermal conductivity measurement. Display omitted •The hygrothermal properties of bamboo particles are studied.•Novel binders from natural resources are used for building bio-insulation materials.•Influence of high relative humidity on durability of bamboo particles is investigated.•Thermal insulation of bio-materials is evaluated under different humidity conditions. Bio-insulating materials are well known to reduce the environmental impact of constructions and are able to regulate the indoor temperature and humidity of buildings. This study investigates the influence of high-absorbing bio-glues based on a protein and lignin compound on moisture transfer and storage as well as on thermal performance of bamboo particleboards. The investigations are based on the moisture buffer value, vapor permeability, isothermal vapor sorption and thermal conductivity. Simultaneously, the mechanical properties and mold growth of these materials, manufactured for the study, are also investigated. The results demonstrate excellent moisture buffer capacity, from 2.13 to 3.26 g/(m2·%RH). The vapor sorption isotherm results exhibit the materials’ high moisture storage, and the vapor permeability behaves like commercial bio-insulating materials. The thermal conductivity of particleboards shows a low value, in accordance with their density and variation in moisture content. In addition, the results indicate mold appearance on the surfaces of specimens after 14 days exposure to 84% relative humidity. Moreover, a comparison of the hygrothermal characterizations between bamboo particleboards and fiberboards (Nguyen et al., 2017) is carefully made to highlight the exceptional features of those bio-boards.