Wood exposed to UV, moisture and temperature results in the degradation of the surface cell structure, consequently changing the surface properties and colour. Absorption of UV light by lignin is responsible for the vast majority of wood degradation and deterioration. Although the discolouration can be removed through planing, it is not always possible and is aesthetically displeasing. There have been many studies conducted to enhance woods properties and prevent lignin degradation. This paper investigates the use of phenol formaldehyde based resin to modify Pinus radiata to improve dimensional stability and resistance to weathering. Untreated and modified boards were exposed to natural weathering (field exposed) and artificial weathering using Arc Xenon system. It was concluded that PF modified wood is less susceptible to weathering than untreated radiata pine in accelerated and field exposed weathering.