TinnerFlow™1st YearSealing, Leakage & MasticCheck first
Butyl gasket needs its thickness to compress and seal. Lay it relaxed, keep it continuous through corners, and remake stretched or torn sections before the joint is bolted shut.
To save time while prepping TDC companion flanges on the ground, you pull and stretch the sticky butyl gasket tape thin to make it reach the corners of a large plenum box, causing it to gap and tear along the metal rim.
Butyl gasket needs its thickness to compress and seal. Lay it relaxed, keep it continuous through corners, and remake stretched or torn sections before the joint is bolted shut. The likely recovery is to check the condition, correct prep/setup if it is within your assignment, and bring the foreman clean information before the work creates rework overhead.
Use this as training guidance. Foreman direction, approved drawings, project specs, manufacturer instructions, employer safety policy, and AHJ/code requirements always control the final answer.