Dropped ceilings, soffits and air leaking

Dropped ceilings (soffits) can be a problem in terms of energy efficiency and air leakage.

These types of structures may involve hidden air cavities where the air will travel till the kitchen or other rooms, causing higher air leakage than other visible sources. Solving this problem provides important energy savings and comfort.

Soffits and Air Sealing

The air infiltration

Wind pressure may easily cause air to travel through eave vents into the air cavities related with soffits and from there to the kitchen or other rooms. Possible common insulation will not stop air penetration: cellulose, fiberglass and other fibrous insulation boards aren’t air barriers.

Recessed light fixtures or other weak elements related with the soffit are the final element in the air leakage chain.

How to solve air Leakage Associated with dropped ceilings

The commonest solution involves sheet goods (drywall, plywood), a convenient sealant and a careful insulation of each cavity.

Possible recessed light fixtures should also be conveniently caulked.

The image above (from US DOE) shows where cavities use to be located and the sealing spots.

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