Insulating the underbelly of your mobile home is the most cost-effective method for controlling heating and cooling costs. Use suitable insulation such as R-19. Insulating the underside of a single-wide trailer takes one afternoon with the proper planning. Two people are needed to insulate a double-wide.
Inspect the underside of the mobile home for damage, holes or older insulation or plastic. Remove the older insulation and plastic. Remove any nests or debris handing from the underside of the floor. Seal any holes with wood cutouts or insulation stuffed into the holes.
Shut off the water and electricity to the mobile home. Unhook the plumbing and wiring connected to the structure. Move the pipes and wires out of the way. Tie off wires and set the pipes on the ground nearby.
Unroll the insulation. Install the insulation between the floor joists working from the front support beams backward. Start the roll at either side between the first and second joists. Set the insulation with the paper backing showing. Tuck the insulation between the joists as you progress across the frame to the opposite side. Affix the insulation using support wires attached to the frame. Repeat the process between each set of joists until the trailer is fully insulated.
Reconnect the plumbing and wiring. Reseal the seams of the pipes to avoid leaks into the insulation. Insulate the pipes and ductwork if needed.
Unroll the fabric roll. Tack the fabric roll over the insulation, pipes, ductwork and wires to provide covering underneath the trailer. Use multiple large squares of fabric to cover the underside of the trailer. Overlap the fabric to ensure no gaps are present.
Replace the skirting around the mobile home. Dispose of old insulation and debris. Place debris and removed material in plastic lawn bags for removal.