Is there a way i can put my forums page into maintance mode 

You can put the full IPB system into maintenance mode from ACP - System - Settings - General Configuration.  The second option is “Site Online”… set that option as off. 

You can even control the message users get during the time the site is marked as offline. 

In case you don't want to put the whole site offline but only a specific application, for example only Calendar/Events, you can put it offline by going to ACP > System > SITE FEATURES > Applications > Events > Lock Icon (on the right).