In two of the performance tests for bathtubs (Dynamic Load, Sec. 2.4, and Surface-Impact Resistance, Sec. 2.12), relatively low values were obtained in the laboratory tests for the pressed-steel bathtubs. Therefore, it appeared desirable to conduct a survey of field damage due to impact for tubs of this type. However, since available resources were limited, it became necessary to select a type of survey that could provide statistically significant data in a reasonable time and at a reasonable cost.

The procedure decided upon was a telephone survey. Two housing developments were first selected from the Washington, D.C., area, where it was known with certainty that only porcelain-enameled pressed-steel bathtubs had been installed by the developers. The two developments selected were:

1. Development "A": This is a very large mediumpriced housing development located approximately 15 miles from the District of Columbia. Occupancies from 1 to 3 years.

2. Development "B": This is a medium-sized development located almost adjacent to the District of Columbia. Homes, which are from 6 to 15 years old, are in the medium-price range.

Telephone numbers were chosen at random from the street names and house numbers known to be a part of these two developments. Secretaries in the NBS Building Research Division then placed the calls requesting the information specified on a survey sheet, a sample of which is included with this Appendix (table B-1).

Table B-2 lists the results of the survey. In interpreting the results the following comments appear to be pertinent:

(1) The homes contacted in Development "A" were built by mass-production techniques. Information was obtained indirectly indicating that extra precautions against chipping damage were not exercised when installing bathtubs, since the builder had found that it was more economical to repair chipped areas after installation than to require elaborate protective procedures by the workmen. This may account for the high incidence of damaged areas reported at the time of occupancy (see table B-2).

(2) The survey indicated that a serious fall had occurred in only 0.9 percent of the pressed-steel bathtubs. The falls that did occur were reported to have caused no noticeable damage to the fixtures.

(3) A total of 20 percent of the 324 tubs was reported to have one or more chips, while 80 percent (258 tubs) were reported as having no impact damage. Most of the chipped areas were small; 60 per cent of the damaged areas were described as less than 4-in in diameter.

(4) No field inspections were made by the project personnel. A few spot checks would have been desirable, but these could not be made because of time limitations. Therefore, since the results were based entirely on the replies of the housewives, the reference level for judging damage probably varied and, for this reason, uncertainties exist in the data. On the other hand, it seems very unlikely that the reported percentages could be in error by any sizable amount since there would appear to be no logical reason for a housewife to supply either a dishonest or an incorrect answer to the questions.