Airtightness sealing around ventilation exhaust unit


I’m currently installing a few exhaust fans in wet rooms, essentially a couple of Aereco BXC2 units. Some are mounted on the ceiling, and others in the walls - there’s various access challenges depending on their orientation.

What are my options for airtight sealing these? I’m thinking about options depending on access from either side (i.e. in-room or from the voids behind), and which would work best.

Has anyone done something similar and could offer advice?



If you are fitting several extract vents and you are airtightening, it beggars the question “where is the fresh air coming from?”. This needs as much planning as the extract if you want healthy, energy efficient ventilation.