Mobile & Manufactured Home Insulation Around Airdrie: Belly Board & Skirting Repairs

The Problem It Solves

A manufactured home is insulated differently from a site-built house. There is no basement wall doing the work; insulation sits in the floor cavity and is held up by the belly board, also called the bottom board: a tough fabric or sheet stretched across the underside of the home. When that sheet is intact, the floor stays reasonably warm. When it is torn by wind, chewed through by mice, or cut open for a plumbing repair and never closed, the insulation sags, falls out, or gets soaked, and cold air runs straight across the underside of the floor. Owners feel cold floors and a furnace that never shuts off.

Frozen water lines usually follow. The water supply typically rises out of the ground into the belly, often protected by heat tape and a little insulation. Once the belly is open and the skirting leaks, the prairie wind pulls cold air under the home and across those lines, and the heat tape cannot keep up during a deep cold snap. A leak from a split line then soaks whatever insulation is left, which stays wet in the closed belly, grows mould and smells, and adds weight that pulls more of the bottom board down. One tear becomes a much bigger repair.

Skirting is the other half of the story. Skirting keeps animals out and slows the wind, but most of it is uninsulated and leaks at the ground, corners and panel joints. On multi-section homes, the crossover duct that carries heat between sections runs under the floor; if it has come loose or split, the furnace is heating the space under the home instead of the rooms. A dryer vent that ends under the skirting instead of outside it pumps warm, wet air into the same space.

How It Works

The fix starts under the home, not at the thermostat. We open or remove the damaged sections of belly board, pull out wet, sagging or rodent-soiled insulation, and check the plumbing, heat tape and ductwork while the cavity is open. The floor cavity is re-insulated with batts or loose-fill, and the belly board is patched with repair fabric and tape and fastened back to the frame and joists so it carries the insulation tight to the floor again. Large damaged areas get new material fastened across them, not a patchwork of tape.

Then we deal with the wind. Closed-cell spray foam, or rigid foam board where the skirting cannot take foam, seals the skirting perimeter at the ground line, the corners and the panel joints, cutting the cold air that sweeps under the home. We leave removable access panels and the skirting vents the installation calls for, keep foam off heat-traced lines, shut-offs and any part of the frame the manufacturer restricts, and keep or replace the moisture barrier on the ground so ground moisture does not rise into the belly. Loose crossover ducts and dryer vents ending under the home are flagged for repair.

What Decides the Specification

The condition of the belly decides most of the specification. A home with a few rodent holes and one sagging section needs patching and local re-insulation. A home where the bottom board has failed along its length, or where years of small leaks have soaked the insulation, needs the damaged board and insulation replaced across the whole area. Duct layout matters too, including the crossover on multi-section homes. Homes on piers with tall skirting behave differently from homes set low to the ground.

The skirting material decides how we seal it. Thin vinyl skirting can distort under spray foam and becomes hard to remove, so rigid foam board lining with foam only at the ground line and joints is often the better choice. Metal and treated wood skirting take closed-cell foam directly. Skirting must also be able to move, because frost heave in the ground under an Airdrie winter can lift skirting that is rigidly locked to both the home and the soil. Around the water riser, heat tape type, the shut-off location and any manufacturer instructions for the home decide what can be insulated and what must stay clear.

Around Airdrie

Manufactured homes around Airdrie sit in a few distinct settings. Some are in established parks where homes are set close together and skirted low; others sit on Rocky View County acreages and rural lots near Crossfield and Irricana, fully exposed to open prairie on every side. The exposed homes take the brunt of the strong west and northwest winds, which is where skirting leaks and torn belly board turn into frozen lines. Rural sites also see mice from surrounding fields, and one winter of nesting can ruin a belly.