Abstract
Careful consideration was given to the change in the snow-sliding performance of coated steel sheets roofs due to deterioration in snowfall area. Samples of the steel sheets that had deteriorated were collected from those actually used as roof coverings in Sapporo City.
As a result of these experiments, the dynamic friction resistance of those sheets which have been used for five years or more is on the upward trend. And no marked change can be found until fifteen years. After that, as irregularities on the outer surface increase, the above resestance has become much more larger.
