Sealing insulated spiral ducting joints

[tanneja]

Am looking at our options for sealing the pre-insulation wrapped metal spiral ducting going from our MVHR to external. 

 

Do people rely on the gaskets in the couplers for their air tightness, or do you silicone the joint, or tape the joint?  If taping, presumably I would need to tape the joins from the inside as taping over the insulation jacket won't be very airtight, which wouldn't be possible at all joins.  Maybe everyone just uses the gaskets to make future access simpler?

[PeterW]

Gaskets are air tight. Duct tape round the joint on the outside also stops it moving in the future. 

[tanneja]

@PeterW thank you, yes that does seem like common sense, just I have seen youtube videos of users applying sealant before offering metal ducting together, I suppose it is down to personal preference and weighing up sealing for better performance vs. ease of disassembly.