Crawlspace Insulation
in Matsqui, BC

Matsqui Prairie is the flat agricultural floodplain west of Abbotsford proper, one of the most productive farming areas in BC and one of the most challenging environments for crawlspace moisture management. The prairie sits essentially at river level, protected from seasonal flooding by the Matsqui dyke system. Within the dyked area, the water table is close to grade through much of the year and can rise to near-surface levels during periods of heavy precipitation or high river levels.

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.