You can select layout of forum pages. Also it’s possible to override this layout for every single forum in its editing page. For finding bbPress forum setting go to Publisher → Theme Options → General → Plugin Pages → bbPress – forums.
Here you can select a layout for all forums page
Override bbPress Layout for Single Forums
For changing layout of every single forum, edit the forum you want, scroll down to fine Better Forum Options. Here you can change the layout for this very forum just like what you did in above.