Crawlspace Insulation
in Abbotsford, BC

Abbotsford is the largest city in the Fraser Valley and the primary agricultural hub of the region. It straddles the transition between the flat Fraser River plain — the Matsqui Prairie — and the upland areas around Sumas Mountain and Vedder Mountain. This topographic divide produces very different crawlspace challenges in different parts of the city. Homes in the Clearbrook and Matsqui Prairie areas sit on some of the flattest, lowest, and most water-retentive agricultural soils in the region; the 2021 atmospheric river event that caused catastrophic flooding in the Abbotsford area demonstrated vividly how quickly these flat, low-lying areas can be overwhelmed by water.

The majority of homes in Surrey and the surrounding communities built before 2000 have fiberglass batt insulation installed between the floor joists in the crawlspace. When this insulation was new and dry, it provided reasonable thermal resistance. The problem is that fiberglass batts installed in a vented crawlspace environment in a high-rainfall climate like ours rarely stay dry. They absorb ambient moisture, sag out of their cavities, and gradually collapse onto the ground. Wet fiberglass insulation has essentially zero R-value, adds weight that can pull down on vapor barriers or staples, and provides a hospitable nesting environment for rodents.

For crawlspaces that are not being fully encapsulated, we install new unfaced fiberglass batts or mineral wool between the joists, but only after addressing the moisture conditions that destroyed the previous insulation. Installing fresh batts into a still-damp crawlspace environment means you'll be back in the same situation within a few years. Proper sequencing matters: drainage, vapor barrier, then insulation.