How To Insulate Ductwork In Attic

But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.

How to insulate ductwork in attic.

Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. The attic ductwork is flex duct work. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order.

Bury the ducts deeply in insulation. How to insulate the attic air sealing the attic energy saving attic insulation duration. The duct insulation should include a vapor barrier cover. Use metal flex or fiber board ducts that are insulated to code.

Tape any punctures in the insulation s vapor barrier to prevent leaks. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Plan to pull up the flooring and layer new insulation on top of the old. Energy saver dealers 204 202 views.

It was new when the ac was put in 7 years ago. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Most insulation relies upon the air space between its fibers to deliver the r value promised. Avoid compressing the insulation.

Check the speed of the blower motor on the furnace. I called out the original hvac company and they took a look and said they saw no water. Use a pressure sensitive vapor retarder tape designed for ductwork. Use a paintbrush to apply duct mastic to the joints where an elbow.

Cover the spray foam with fire retardant spray. Mechanically fasten and mastic seal all duct connections. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Cover the metal ductwork with closed cell spray foam.

When these ducts are exposed to exterior air the plastic jacket never gets cold enough to permit condensation because the hot attic air keeps the plastic jacket warm. Because the simplest and cheapest way to insulate an attic is to add material to the floor. That s what happened to the ducts in the lead photo of this article. The foam provides a vapor barrier so the ductwork won t sweat.

Most attic ducts are insulated flex ducts that is flex ducts with r 6 or r 8 fiberglass insulation along with an exterior polyethylene jacket.