MH - Blown Belly Insulation

Detail ID 4.0302.9
Exposed Floors
Desired Outcome

Continuous, contiguous, safe, pest and weather resistant thermal boundary

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


  • MH
Specification Objective

Verify that installation area is free of:

active water leaks, fuel leaks (i.e., gas, oil, propane), and pest intrusions

uncovered electrical junctions

improperly terminated devices (ventilation fans, dryers, plumbing stacks, condensate lines, combustion appliance flues/chimneys, etc.)

unshielded high-temperature devices (non-IC rated recessed lights, chimneys, flues, vents, etc.) unless they are zero clearance devices

insulation escape openings

Verify that installation area is:

intact and able to support insulation weight

Air and duct sealing is complete

Verify that all plumbing is within the thermal boundary, or insulated appropriately

Space safe and prepared for insulation

  • MH
Specification Objective

Select insulation that:

has a flame spread and smoke development index of 25/450 or less when tested in accordance with ASTM E84 or UL 723

are of minimal water absorbency

are noncorrosive

Select safe materials

  • MH
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)

Select safe and effective sealants

  • MH
Specification Objective

Fill all belly cavities to full capacity and prescribed R-value ensuring that all ductwork and plumbing has sufficient insulation value to prevent condensation or freezing

Continuous and contiguous thermal boundary

  • MH
Specification Objective

Install closure system over all access holes that is weathertight, patched with like materials that are stitch stapled and adhered to the existing closure system with permanent adhesive, and meets applicable fire safety codes

Weathertight, durable, and safe access closure

  • MH
Specification Objective

Post a dated receipt signed by the installer that minimally includes: Installed insulation type, coverage area, installed thickness, minimum settled thickness, installed R-value, and number of bags installed

Comply with 16 CFR 460.17 and document contract compliance

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Exposed Floors