ticity and tensile strength sufficiently to wear well under adverse conditions. 

 Patching can be done easily, and additional coats adhere to the original application 

 and are not unsightly. 



COSTS AND COMPARISONS 



Labor Saving 



In approaching the subject of costs and of the savings to be effected by the 

 use of plastic, as compared with other materials, it is to be recognized that to a 

 large extent the reduction in cost is attributable to the difference between the 

 amount of time (man-hours) required for the application of mineral asphalt and 

 paper and for the application of plastic sealing compound. The limited scope of 

 the operations studied would seem to make a comparison difficult; however, the 



?M 





N 10139 



Figure 23. — Cleaning plastic spray equipment in the open air. 



variation between the time involved in the two types of operations is so extreme 

 that one conclusion is possible. The application of plastic sealing, material and 

 labor both being considered, results in a definite saving as compared with other 

 methods. 



Paper and Mineral Asphalt 



In sealing a group of storages at Wilmington, N. C, with paper and mineral 

 asphalt, a total of approximately 366 man-hours was required to seal one floor of 

 a particular section. This amount of labor held very consistently throughout the 

 four two-story sections which were sealed. Fumigations subsequently made at 

 this warehouse indicate that an extremely satisfactory job had been done. Paper 



30 



