Snow sliding phenomena on a roof by using the electrically heated roof-tile (ERT) was investigated on the basis of the results of snow sliding experiments carried out from December 1989 to February 1990. The roof is covered with the lines of the ERTs and non heated tiles, and each line of ERTs is electrically heated. Most snow sliding occurred at partial area on a roof but not whole area. It was found that the occurence of snow sliding strongly depends on the surface temperature of non-heated roof tiles. Experimental results showed that snow sliding on the roof ocurred after the surface temperature of non-heated tiles increased to about 2°C. The partial snow sliding might be caused by the non-uniform distribution of surface temperature on roof. The surface temperature of a non-heated tile increases as the input electric power to ERTs is high and the space between the lines of ERTs is narrow. The surface temparature is influenced by snow depth as well as.wind direction. During the period of experiments, west wind blowed dominantly, thereby there were lesser snow precipitation at the west side of the roof than the east side. It seems to cause non-uniform distribution of surface temperature.

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