Sealing Dropped Ceilings

Detail ID 3.0102.10
Topic
General Pressure Boundary
Subtopic
Specific Air Sealing
Desired Outcome

Airtight, safe, durable seals that remain in place, and prevent moisture and air movement @ 50 Pascals of pressure

SF Single Family Site-Built Housing
MH Manufactured Housing
MF Multifamily Housing

Specifications

  • SF
  • MH
  • MF
Specification Objective

Select sealants that:

are compatible with their intended surfaces,

allow for differential expansion and contraction between dissimilar materials,

meet the requirements of the applicable fire safety code (e.g. thermal or ignition barriers), and

for use inside the pressure boundary select low volatile organic compound (VOC) sealants that meet independent testing and verification protocols

Select safe and effective sealants

  • SF
  • MH
  • MF
Specification Objective

Select materials that:

adequately support applied load and are permanent air barriers,

meet the requirements of the applicable fire safety code (e.g. thermal or ignition barriers), and

for use inside the pressure boundary select low volatile organic compound (VOC) materials that meet independent testing and verification protocols

Select safe and effective materials

  • SF
  • MH
  • MF
Specification Objective

Install support material for spans wider than 24", except when air barrier material is rated to span greater distance under load (e.g., wind, insulation)

Support material installed for any walking/working surface (attics or floors) will support the weight of a worker and any insulation applied in the area

Ensure sealing materials remain in place and support applied loads

  • SF
  • MH
  • MF
Specification Objective

Remove any material from the sealing area that will prevent full adhesion of the selected sealant

Surface is clean and ready to accept sealant

  • SF
  • MH
  • MF
Specification Objective

Install a permanent air barrier either above or below the existing ceiling material that will structurally support the final insulation level

Align pressure boundary

  • SF
  • MH
  • MF
Specification Objective

Apply a continuous seal at all seams, cracks, joints, edges, penetrations, and connections of the pressure boundary while applying sufficient pressure to push sealant into any gaps or cracks and contact any backing or infill material required

Fully adhered, airtight, and durable seal

  • SF
  • MH
  • MF
Specification Objective

Install only noncombustible materials and sealants with an ASTM E136 listing in contact with any device producing 200 degrees F or more (chimneys, vents, flues, etc.)

Prevent a fire hazard