How to Repair the Belly Insulation of a Mobile Home

Keith Allen

The belly, sometimes referred to as the underbelly, of a mobile home is defined as the floor of the home as it is accessed from the underside. The insulation of the belly can be damaged by moisture, rodents or simply decay over time.

Even simple repairs on the belly of a mobile home become challenging due to space restrictions. Most of this repair task will not be difficult, but will be uncomfortable and time consuming.

Repairing Small Problems

  1. Locate the tears and holes in the belly of the mobile home. Clear the area of the hole of any dirt and debris. Look particularly for rodent nests.

  2. Add insulation to replace any that has fallen through the hole. Poke the insulation into place with a small push stick.

  3. Patch the hole with flexible polyethylene tape. These tapes resemble duct tape but are made of a similar material to what is used in the belly of the mobile home. Apply heat with a hair dryer or heat gun to set the tape.

Large-Scale Repairs

  1. Remove the fabric belly of the section of the mobile home to be repaired. The belly of some mobile homes is divided into sections by support beams. Work on each section separately, as needed.

  2. Replace insulation that has fallen free from between the floor joists. Fasten paper-backed insulation in place with silicone caulk.

  3. Install the new polyethylene fabric belly. Fasten the fabric at the edges of the mobile home by driving nails or wood screws through a thin piece of wood over the fabric.

  4. Seal any gaps around plumbing or electrical services with polyethylene tape.

  5. Tip

    Use power tools such as an air nailer or power screwdriver when working under a mobile home. Space limitations will make swinging a hammer difficult, if not impossible. Polyethylene belly material is available from mobile home retailers and repair services. The standard widths are equivalent to standard widths of mobile homes.


    The polyethylene tape will outlast duct tape. Unless you enjoy crawling under mobile homes, it makes a good investment in time and effort saved.