How To Seal Ductwork In Attic

The tape and the caulk stick a lot better when there isn t a lot of dust there.

How to seal ductwork in attic. Use zip ties to secure any loose ducts to the attic floor. Steps to sealing attic air ducts locate the source of the thermal leaks by inspecting the ductwork while the air conditioner is running. To apply insulation measure the circumference of the duct. Liquid duct sealant provides a tight seal around odd shaped metal joints.

Duct sealant is another product that is commonly used to seal up duct leaks. Duct sealing by michael church here and in this video we re going to show you how and why it s very important to air seal the run of the ductwork. It s important to seal the exhaust fan well at the joint so the air doesn t bypass or leak out of the joint. Air duct sealing video transcript.

Make sure the duct is secure in place. After you have cleaned the surface simply place a strip of the aluminum foil tape over the leak or use your mastic sealant and a paint brush to seal it. And it costs about 10 bucks but it ll save you more than that in the first year you can t go wrong buying this. Well if they re not properly sealed they are.

Use a continuous strip of foil tape to seal off all longitudinal seams along the straight runs of the duct. To seal this instead of regular duct tape i m going to use some acrylic faced aluminum tape. This pasty thick paint like substance can be applied to cracks and gaps in your ductwork with a caulking gun and spread with a paintbrush or if using a gallon pail just scooped and applied directly with the paintbrush. You all have duct work either in your attic or crawlspace or something like that.

I make sure to keep that insulation away from the adhesive face so i don t contaminate it. Possibly in an unfinished basement. Don t use duct tape. Tape works especially well on fiberglass and flexible ducts as well as flat metal ducts.

Apply a generous amount of sealant mastic over the thermal leak. Before you do anything grab your rag and make sure that the area is clean before applying either mastic sealant or foil tape. To seal ductwork the old fashioned way.