AbstractTo improve technical performance of wood siding, treatment with maleic anhydride was applied. The effects on technical performance of drying time and esterification temperature parameters were analyzed. Wood samples of lodgepole pine and white pine were treated and tested. Results indicated that treatment improves technical performance of wood (dimensional stability, fungal degradation resistance, and accelerated aging). FTIR spectroscopy analysis showed spectra with peaks at 1750 to 1730 cm-1. These correspond to ester bonds formed between wood hydroxyl groups and MA carboxylic acid groups. SEM images indicate that the MA quantity in wood cavities was increased with decreasing esterification temperature. Weight percent gain (WPG) increased with decreasing time and temperature of esterification. Artificial aging and fungal degradation performances were monitored using FTIR analysis. Esterification temperature had no important effect on fungal degradation. Weight loss after fungal exposure of treated samples was not only due to fungal action but also due to evaporation of MA during the drying step. Regarding artificial aging, degradation of wood components and ester bonds were less for samples esterified at 180 °C than those esterified at 160 °C or 140 °C.