Question about liner install

[Gargra03]

Hello everyone
I am a newbie here and we recently purchased a home with a 6 inch liner installed with an insert. After checking everything out it looks as the the liner was cut flush at the top of chimney and with Roxul stuffed around it and a 13x18 chimney rain cap was installed. Do I need to remove the rain cap and install a top plate then rain cap or will the current setup suffice.

 

[webby3650]

You should have a top plate at least. I've reused the original masonry cap on occasion, but still use a top plate and storm collar clamp.
I would also assume the installers probably skimped on other things as well, like insulation on the liner. What insert is the liner hooked to?

 

[Gargra03]

It is hooked to a Ashley bay front stove. The liner looks uninsulated but the chimney is a interior masonry chimney. If I out a top cap on how would you suggest I extend the liner enough to secure it in top place.