1. Verify 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.

2. Verify 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.

3. Belly repair

• Choose appropriate option from steps 3a - 3b to patch mobile home belly.

3a. Belly repair: small

• To patch a flexible belly, use adhesives and/or stitch staples to bind the flexible patch to the flexible belly material.

• In weaker areas of the belly screw wood lath to the framing to reinforce belly material.

3b. Belly repair: large

• Use belly fabric or house wrap to cover damaged area. Creating a "new" belly.

•  Secure edges of fabric by rolling a 1x2 into the edges and securing the 1x2 to framing members of trailer with appropriate fasteners.

•  Tape any seams with manufacturer approved tape AFTER properly preparing surface to ensure adhesion.

4. Install insulation

•  There are two methods for installing loose fill fiberglass insulation in a mobile home belly.

• Blow in fiberglass through belly material; steps 5-5a.

• Blow in fiberglass through rim; steps 6 - 6e.

• Pick the most appropriate method for the job you are working on.

5.  Blow in fiberglass through belly material

• Loose fill fiberglass is the only material to be used in Utah WAP.

• Cut  a hole in the belly material just big enough to fit the insulation hose through it.

• Using the insulation hose fill the cavity taking care not to over pressurize and cause a blowout.

5a. Patch access hole

•  After insulating the belly patch the access hole  with adhesives and/or stitch staples to bind the flexible patch to the flexible belly material.

6. Blown in fiberglass through the rim

• Loose fill fiberglass is the only material to be used in Utah WAP.

• Follow steps 5a-5e to install blown in fiberglass in the mobile home belly.

6a. Remove skirting

• Remove skirting to gain access to the rim joist.

• Use caution older sun damaged skirting can become brittle.

6b. Drill hole

• Drill hole big enough to fit fill tube.

6c. Blow in insulation

• Fill cavity to manufacture specified density for the material being used. 

• Watch belly material and repairs for blow outs.

• Best practice would be to go inside the home and verify ducts were not breached with insulation materials.

6d. Plug the hole

• Caulk plastic or wood plug in place.

6e. Re-attach Skirting

• Re-attach all skirting that was removed to gain access to the rim joist.

7. Worst Case Draft test

• Conduct a Worst Case Draft (WCD) test to verify Category I, II, and III appliances are venting safely before leaving home for the day.

• Testing shall be recorded using the Utah WAP Worst Case Draft Test form.

8. Install insulation certificate

• A dated insulation certificate signed by the installer will be posted on a wall in the space where the furnace is located, a utility room or an approved location inside the building.

• Certificate shall include:

  • Installed insulation type

  • Coverage area

  • Installed thickness and minimum settled thickness.

  • Number of bags installed in accordance with manufacturer specifications.