Permavent Apex Untaped Breather Membrane, 180g - 1m x 50m
Permavent APEX has Sd value of 0.01m. Permavent APEX has full BBA Certification for use in both cold and warm non ventilated roofs. Permavent APEX is fully compliant with BS5534:2014+A2:2018 Code of Practice.