Apprentice question
Field check
Standard work. Do it right, keep moving.
A saddle tap must hug the barrel. Dress the flange or use the correct saddle size before sealing it.
['If the saddle curvature does not match the main duct, a wide heel gap becomes a structural air leak. Mastic alone will crack if the metal is not fitted first.', 'Remove the tap, reshape/dress the flange to match the barrel, confirm the opening size, reset with approved gasket/sealant, and fasten evenly around the perimeter.']