Wood is a versatile and remarkable building material that has been utilized for a long time in an assortment of applications. Despite the fact that untreated wood is more prone to deterioration and has less inherent resilience, preservatives are used to prolong the service life of wood. Numerous preservatives are available to extend the durability of wood against deterioration. The environmental concerns associated with first- and second-generation wood preservatives encompassing pentachlorophenol (PCP), chromated copper arsenate (CCA), etc., such as the leaching of preservative chemicals from the treated wood, leads to air, soil, and water contamination and disposal-related issues, which have driven the emphasis on the use of carbon-based third-generation wood preservatives, particularly triazoles. The development of preservative solutions with minimal adverse impacts on human health and the environment has received more attention. In the present study, we investigated the possibility of developing a formulation using organic fungicides (tebuconazole) and inorganic salts (copper sulphate and boric acid), and their efficacy was screened using the petri plate bioassay. At low concentrations, few of the formulations exhibited 100% inhibition against the white rot (Trametes versicolor) and brown rot (Oligoporus placenta) fungi. Additionally, the screened formulation was used in mango wood (Mangifera indica) and exposed to fungal decay. The wooden specimens treated with the screened formulation improved decay resistance. The rResults indicated a gradual reduction in percent weight loss, of 2.37% and 3.39% against white rot and brown rot fungi, in treated samples after exposure. The changes in chemical structure and microstructure after exposure to fungi were studied using Fourier transform infrared spectroscopy and scanning electron microscopy techniques. The potential effect of organic fungicide incorporated with inorganic salts increases resistance against fungi. Further SEM micrographs and FTIR spectroscopic analysis of decayed wood confirmed less degradation in treated wood compared to untreated specimens.