How to keep an encrypted home directory mounted (even after logout)

Question

Sometimes I'd like to ssh to a machine, mount my encrypted home directory and disconnect and keep the directory mounted.

What I managed already to do is

• ssh to my machine (without password only public keys are allowed for security reasons)
• create a tmux session
• mount the file system in the tmux session
• cd into the home directory
• execute some script that will run for a long time
• detach the tmux session
• logout

if I login again and attach to the tmux session, I see, that my script continues to run as long as it uses only relative path names.

However if I access absolute path names I see, that my home directory has been unmounted.

Is there any trick to keep it mounted.