A thermal barrier and a vapour barrier sound similar, but they do completely different jobs. A spray foam thermal barrier protects foam insulation from heat during a fire. A vapour barrier controls moisture and helps prevent condensation and mould inside your walls. Covering spray foam with plastic sheeting doesn't meet fire protection rules. Closed-cell spray foam at sufficient thickness often acts as its own vapour retarder, which makes it a strong choice for wet West Coast homes. Learn the difference and avoid common renovation mistakes with our guide: https://westerninsulation.ca/spray-foam-thermal-barrier-bc/