Trailers and mobile homes are an inexpensive housing option, but they're not known for their stellar performance during cold weather. Anything you can do to keep a trailer warmer is probably worth the effort. Because trailers lack a full foundation, they are susceptible to cold air and drafts coming up from under the floor. Installing insulated skirting around the edges of the trailer can reduce this problem and keep the whole trailer much warmer.
Things You'll Need
Rigid foam insulation panels
Locate the access panel in your trailer skirting, and crawl in underneath the trailer. Inspect the area for other problems while you are there. Be sure there are no leaks in the floor or animals living under your trailer before you insulate.
Measure the distance from the ground to the underside of your trailer. If it's exactly 24 inches, you're in luck because this is the manufactured width of rigid foam insulation panels and you won't have to cut them. If it's less than 24 inches, cut a panel lengthwise to fit this dimension. If it's more than 24 inches, install a full panel, then cut another panel to fill the remaining area.
Attach the panel to the inside of the trailer skirting by applying dollops of construction adhesive every 12 inches in a grid pattern. Press the panel against the inside surface of the trailer skirting.
Cover the joints between all of the foam panels with construction tape. This tape is made of heavy-duty cellophane, and it will help to prevent any drafts that try to get between the panels.
Wear a mask while under the trailer if you are sensitive to mold and dust.