How To Insulate Ductwork In Attic

Mechanically fasten and mastic seal all duct connections.

How to insulate ductwork in attic.

I called out the original hvac company and they took a look and said they saw no water. The attic and walls are one of the most important areas to insulate in any space. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order. 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. Use metal flex or fiber board ducts that are insulated to code. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. The foam provides a vapor barrier so the ductwork won t sweat.

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. Most insulation relies upon the air space between its fibers to deliver the r value promised. Use a pressure sensitive vapor retarder tape designed for ductwork. Bury the ducts deeply in insulation.

Check the speed of the blower motor on the furnace. How to insulate the attic air sealing the attic energy saving attic insulation duration. 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. Plan to pull up the flooring and layer new insulation on top of the old.

It was new when the ac was put in 7 years ago. The attic ductwork is flex duct work. Cover the metal ductwork with closed cell spray foam. When it comes to insulation ductwork matters too.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Avoid compressing the insulation. But what about the parts behind the walls and in the ceiling. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct.

The duct insulation should include a vapor barrier cover. 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. If necessary switch the wires to reduce the blower to its lowest speed. Tape any punctures in the insulation s vapor barrier to prevent leaks.

That s what happened to the ducts in the lead photo of this article.