This study assessed the protective action against biological fungal growth of two consolidating products applied to wood. Experiments examined effects produced by white and brown rot fungi on White poplar (Populus alba) and Norway spruce (Picea abies) treated with two consolidants, Paraloid B72 and Regalrez 1126, applied both individually and together, with the aim of evaluating differing levels of penetration into and location in the wood. The main aim was to test whether these products, which are generally applied during restoration, could act against fungal growth on healthy wood or increase biological attack. Changes in both morphological and chemical levels induced by fungal attack were observed, susceptibility to biological colonisation was analysed, and protective efficacy was tested. Several series of wood samples treated with the above products were placed on agar plates inoculated with two fungal species (brown-rot decay fungus, Fomitopsis palustris, and white-rot decay fungus, Trametes versicolor) and growth was observed for 2 months. The results for Norway spruce showed selective development of one of the two rots according to product application: both products applied together caused slowed growth of both fungal species. The White polar samples treated with the consolidants, both alone and together, all showed similar behaviour. SEM analysis was also carried out in order to observe changes in wood microstructure induced by rot colonisation.