BC Building Code requires a minimum effective R-value of R-20 for basement walls in Langley — and the best way to achieve it is with closed-cell spray foam applied directly to the concrete foundation wall. Unlike fibreglass batts, spray foam bonds firmly to concrete, creates a complete air and vapour barrier in a single step, and does not absorb moisture over time. It is the most durable and moisture-resistant option for a Langley basement, where ground dampness and cold concrete surfaces are persistent year-round challenges. Western Insulation's R-value guide explains what R-20 means in practice, which materials reach it most efficiently, and why your basement insulation choice directly affects the comfort of every floor above it. Read the full basement insulation R-value guide for Langley BC — then explore our basement and crawlspace insulation service in Langley to book a free assessment.