Changes in tensile properties, sample size, interfacial strength, and thermal conductivity of melt-laminating layers of wood/ebonite natural rubber (NR) and expanded ethyelene-propylene diene rubber (EPDM) for polymeric roofing applications were monitored under a period of UV aging times for 60 days, the results being compared with single rubber layers of wood/NR and expanded-EPDM. The experimental results suggested that the tensile modulus of the wood/NR-EPDM melt-laminating layer increased with increasing aging time. The tensile strength of the wood/NR layer decreased after prolonged UV aging, and positioned between that of the wood/NR and expanded-EPDM layers. The sample size reduction of wood/NR layer with expanded-EPDM top coating layer was lower than that for wood/NR single layer. The peel strength of the wood/NR-EPDM melt-laminating layer was found to decrease with increasing UV aging time as a result of delamination of the rubber layers. The thermal conductivity of the wood/NR-EPDM melt-laminating layer decreased from 0.085 to 0.070 W/m K with increasing aging times upto 40 days, but tended to increase to 0.080 W/m K at the aging time of 60 days. The experimental results in this work clearly suggested that expanded-EPDM could be used as protecting layer, not only for moderation of photo-oxidative degradations of wood/NR layer for roofing application, but also for minimization of dimension changes of the wood/NR-EPDM melt-laminating layer. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 335-342, 2010