u2212 0 306 u2212 0 247 1 0 04 1583 u2212 0 042 u2212 0 034 2 0 08 1609 u2212 0 027 u2212 0 021 3 0 16 1583 u2212 0 015 u2212 0 014 control after 0 1585 u2212 0 409 u2212 0 145 both wet 12 u00d7 4ft production boards and final dried 12 u00d7 4 f production line boards were also measured in accordance with astm c473 95 to determine the amounts of shrinkage of their widths and lengths after drying the more the boards shrink the less is their dimensional stability the results are reported in table 6 the data in table 6 show that boards prepared in accordance with the invention were more dimensionally stable than control boards at 0 04 stmp addition and above no length or width shrinkage was found sag resistance under humidified and condensation conditions production line gypsum board an additional test illustrates sag resistance provided by the compositions and methods of the present invention more specifically production line ceiling board was tested wherein controlled condensation was allowed to occur at a vapor barrier placed between the ceiling board and the joists the method for this test is as follows a small scale attic and room enclosure was constructed the attic space was insulated on its top and sides and kept cool to obtain controlled condensation at the ceiling the ceiling area was 8 foot u00d7 8 foot with 2 foot u00d7 8 foot framing and 24 inch o c the room space was enclosed by a 6 mil poly vapor barrier at its top and.