No need to wait. Most companies that register domains for you will allow you to pre-order domains before they expire. Once the domain becomes available they snap it up for you. Have a chat to someone like Black Knight (no affiliation) and they'll explain how it works.
been in touch with blacknight, have been told i have to wait till it "drops off." and that I will have to keep checking till its available. (it expired on 18th August) .ie domain
It's usually 30 days, that's the standard grace period. Basically the person who originally owns it, is given 30 days to renew before it goes on the market again.