Dave Grohl has a ''crazy idea'' for the next Foo Fighters album.

The 'Best of You' hitmaker has begun working on the follow-up to 2011's 'Wasting Light' and he has already decided he doesn't want it to be a ''conventional record''.

He said: ''[I have] a crazy idea of what I want to do with the next record and how we record it. It's not conventional. It won't be a conventional record.''

And it seems the rocker is even keeping his bandmates in the dark about his plans for the album.

Drummer Taylor Hawkins said: ''[The album is] just sort of a germ in Dave's head at this point. He says he's got a lot of ideas. We haven't really gotten down to brass tacks. I don't know what the path will be. It's always a little different, which is good.''

While work has begun on the record, the group don't yet know when it will be released.

Dave told Billboard magazine: ''Well, we're just writing right now. When we start working on a record, what I've found is we work best at our own pace, and sometimes it happens quickly and sometimes it takes a while.''