Can a manhole be vacuum tested with an Internal Seal in place?
The proper installation of an Internal Chimney Seal into a properly constructed grade adjustment area will be able to pass a manhole vacuum test in accordance to ASTM C1244. However, we do not recommend this test be adopted as an acceptance test for “Chimney Seals” since the seals are designed to be water tight and not “Air Tight”. The upper portion of the manhole will almost never be subjected to the kinds of pressure created during a vacuum test and therefore should not be tested as such. A second vacuum test at half the standard pressure or a simple water test should be used for acceptance testing chimney seals.
