OS 10.5 - Time Machine, File Fault, and encrytpion

Hello All!

I amusing file fault to encrypt my home folder. I keep my external drive mounted when logging out in order to ensure a time machine back-up occurs.

My question is whether or not the time machine back-up is encrypted because file vault is turned on.

Do I need to do something to protect the data on the external disk?

Also, to what extent does file fault encryption protect my data. I read in Macworld that file vault is fine for most users. However, third party applications may need to be used for maximum security (October 2008 issue).

Thanks!