抄録
This paper treats the wear by aging of asphalt-built roofs by selecting and examining their actual pieces in order to contribute to fundamental data for maintenance of buildings. Twenty-six telephone and telegraph office buildings aged from two to thirty-eight years were selected from all over the country and test pieces of asphalt waterproofing were picked out when the buildings were extended or repaired. They were examined about tensile strength of asphalt belt or roofing, and penetration or softening point of asphalt, etc. moreover, consequences of observation of outlook, etc. were added, the summary wear-degree was considered. As the result, the following conclusion was obtained. The relation between wear of 4-sheeted asphalt water-proofing and age is y=2.0t^<1.08>. If the remains were 20%, their longevity is considered approximately thirty years.
