Crawlspace Insulation
in Brookswood, BC

Brookswood is a unique community in Langley Township, characterized by older rural residential development on large lots with sandy, quick-draining soils — a distinct contrast from the clay-heavy profiles common elsewhere in the Fraser Valley. The sandy soil conditions mean that flooding and standing water are rarely concerns in Brookswood crawlspaces; the primary moisture challenge here is vapour diffusion from the well-drained but still moisture-bearing sandy soil beneath.

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.