Huge transaction log size even after truncate and shrink

Hi all,
I keep seeing the transaction log grow to a size of 10 GB ( disk space) on a customer database even after regular hourly backups of it.
I also shrunk the log to 100 mb but now it's back up.
Any ideas on what i can look at and if I need to increase the frequency of backups as it's taking a lot of unnecessary disk space.
Much appreciated
Johnny

JRMTL,
Keep in mind, that all transactions go trough the transaction log.
If poorly designed transactions or natural large transactions are issued againts the server it is normal for it to grow !
Is the DB mission critical ? Doesn't it need point in time recovery... ?
If for example the DB isn't mission critical and you only need daily or weekly backups and don't need PITR you can put your DB in SIMPLE RECOVERY MODEL.
Hope this litle piece of text help you !.
Best Regards,
Paulo Condeça,