How To Insulate Around Air Ducts In Floor Joists

In unfinished attic spaces insulate between and over the floor joists to seal off living spaces below.

How to insulate around air ducts in floor joists.

Whenever possible run the insulation between the obstructions and the subfloor. How to finish a basement wall. Cut slits in the insulation so you can run it on either. Use foam sealant such as great stuff to seal the joints.

Place rigid roam against the rim joists then caulk along the insulation. To insulate the exterior you have a choice between sleeve style insulation and blanket wraps which literally wrap around the ductwork. In older homes where the spacing of the floor joists varies you may need to cut the insulation to width as well. Adding insulation to your water heater can reduce standby heat losses by 25 to 45 percent which in turn reduces your energy bills.

1a attic access door. Water heater and water pipes. To install sleeves you must either disassemble the ductwork and slide it on before reassembling the ducts or as many homeowners find themselves doing slit it and wrap it around like the blanket style material. Enjoy better floor to floor climate control in your home by installing ceiling insulation.

Fiberglass insulation and expanding foam seal the open top of hollow concrete blocks. If there s room for a 3 5 batt with a paper facer to snug up to the duct fiber side to the duct paper downward toward the ceiling gypsum that s good enough foil tape works well if the ducts are shiny and clean but for older dirtier ducts duct mastic is more reliable. Airtight insulation reduces heat loss through the rim joist band joist. Fiberglass insulation works as an insulator because it traps air in the fibers of the insulation and slows the collision of warm and cold air.

Use caulk or foam sealant to seal the joint between the top. Fill the ends of joist bays with rectangles cut from rigid board insulation. If the fiberglass insulation gets wet or very damp it will begin to collapse get heavy and fall from the floor joists rendering it useless to trap air and be an insulator. It is important to secure insulation and cover it with a vapor barrier in order to prevent moisture and the mold that often follows close behind.

Install the insulation with the vapor barrier facing up toward the heated living area of the house. If the crawl space is ventilated which is ideal because it aids in the elimination of moisture then fiberglass insulation can be easily installed under the subfloor between the floor joists.