In TDC, TDF and Ductmate fittings there’s usually an open gap of remaining V Notch in between where the duct is joined with the corner. This gap needs to be sealed, otherwise it can become a point of leakage when TDC, TDF or Ductmate is used as the transverse joint connection. The Duct Shop is typically […]
Filling the gap caused by the V Notch on TDC and Ductmate Fittings Read More »
Rolled Mastic What exactly is rolled mastic…? Rolled Mastic is the equivalent of liquid duct sealant but on a roll. Sitting on a shelf it might appear as an oversized roll of the aluminum foil red letter tape—it looks like aluminum foil tape even when it’s installed. But this product is more like Duct Sealant
Sealing Duct from the Interior and why it ensures the tightest seal… Many Sheet Metal Contractors recognize that ALL of the Duct’s Pressure is from the inside…pushing out, and that sealing the lock’s interior is not only aesthetically better but also better from an engineering perspective. Many engineers don’t want to see mastic on the
Sealing Duct from the Interior Read More »
Duct Sealant—Longitudinal vs. Transverse Sealing Rectangular Ductwork: Choosing a Sealant with characteristics that match the Seam/Connection and the point of application Duct Sealant Characteristics Longitudinal Seam: a narrow lock that usually is long and continuous and moves in one direction. Covering this lock with more than 1/2“ width of sealant makes for a messy appearance and a waste
Duct Sealant—Longitudinal vs. Transverse Read More »
SMACNA and Mastic on Rectangular Duct “Rectangular Longitudinal Seam leakage for Pittsburgh and Buttonlock seams is low compared to that in Transverse Joints” SMACNA Duct Construction Standards 2005 But SMACNA also states that “the designer is responsible for determining the pressure class or classes required for duct construction and for evaluating the amount of sealing necessary”.
Cartridged Duct Sealant for the cleaner application on Longitudinal Seam Duct Sealant applied by cartridge gun to Pittsburgh Lock on Duct Interior With a Brush and Bucket this is what sealing the interior duct Pitts seam often looks like…not very good. Feedback is that some contractors apply the mastic to the Longitudinal seam (the Pittsburgh
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Pitts Seam Sealant Sealing in the Pocket Applying Sealant into the Pittsburgh Seam is different than applying it on the Pittsburgh Lock but either means accomplishes the same result. This image shows Exterior view of Pittsburgh’s Female Pocket with the Pitts Seam Sealant clearly visible at top near where the Longitudinal Seam and the Transverse Connector (TDC in
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