Mushroom Vent

[@ChrisCoCreated]

You are absolute stars for posting this. Just the problem I've got, thank you!

[@NeilTaylor]

Glad you found it useful.

[@Kat-xi6wj]

Great job.I have the same problem I try fix it like you.What size mastic sealing strip you have?
Thanks

[@NeilTaylor]

I can not remember as my wife got it on-line, but it came on a roll.