Vapour barrier protects homes by preventing water vapour from escaping from the building envelope. Leaking vapour barrier can lead to condensation in the walls and wood rot. In Canada the Canadian General Standards Board (CGSB) developed a standard for greatly improved vapour barrier that is now a requirement of the building code for new home construction.
Film made to meet the requirements of CAN/CGSB-51.34-M8 has clearly defined and tested properties which can only be achieved with first quality ingredients and careful manufacture and testing. The film also needs to contain stabilizers that are designed to ensure that the film will last the lifetime of the house.