Any attic wall that adjoins an interior space should be insulated and air sealed! Where air barriers (See Info Sheet #1.3) are not installed on the unconditioned (attic) side of the walls, very hot or very cold air in the unconditioned space can easily flow through and around the wall insulation. Figure 1 depicts cold [...]
Make sure to Seal All the Connections in your Flex Ductwork Some of the connections to pay attention to are: the pressure box, registers, collars and boots. Connections at the junction box should be sealed with a heavy layer of mastic. Mastic should be applied with a paintbrush around the entire perimeter of the collar [...]
An Easy Do-It-Yourself Home Improvement Project The Correct Way to Seal Duct Collars with Mastic Step 1 Apply mastic approximately 2” wide uniformly around the collar of the metal fifing. Reference the data on mastic container for application rate, application thickness, cure times and handling information. Step 2 Slide at least 2” of duct core [...]
Air Sealing of Penetrations in Subfloor and Ceiling All holes and penetrations in the top plates, ceiling and subfloor should be sealed with expandable foam or caulking to prevent air infiltration into the conditioned space of the building. Holes are often cut or drilled for piping or wiring and can be found by following pipes [...]
Seal Ducts for Enhanced Energy Efficiency Depending upon the size of the leak, tremendous amounts of air can be lost from the duct work. Repairing those leaks and making sure that they don’t return is relatively easy. Sealing the connections between flexible ducts, plenums, junction boxes and boots/registers keeps the HVAC system running clean and [...]
