Sealing Floor Ducts

How to seal duct boot to ceiling with fiberglass mesh tape and mastic for gaps larger than 3 8 inch.

Sealing floor ducts.

Heat must travel a shorter distance and enters. Use caulk for gaps that are less than 3 8 inch. The tape does a great job sealing but as the metal expands and contracts with seasons it can begin to come loose. This is one of those things that can go unnoticed but have.

Diy duct sealing only goes so far. If you really want to seal all of your air ducts you will need to contact a professional. Only qualified contractors should perform changes to your duct system. Use fiberglass mesh tape and mastic where gaps are larger than 3 8 inch.

That is where the duct sealer comes in. Floor ducts are effective because they deliver heated air at floor level. Use your putty knife to generously coat the aluminum tape with duct sealer. An odor alerted me to standing water debris and even a dead animal in the ducts below my floor.

I have galvanized air. Floor vents are typically used in homes where the furnace is in a basement or the ducts the piping from the furnace travel through an underground crawlspace. The heat then rises and continues to warm the rest of the room. Watch this video for more tips to seal air ducts.

Seal the seam between the duct boot and the flooring or sealing framing and finish material. If you live in a house with a crawl space there is a good chance the floor vents are not sealed.