Hi Danielle,
 
Thank you for your question.
 
As you can feel the central system of the base through your mattress, you would be better boarding over the entire base with either MDF or Plywood to make it a more solid base.  This should then sort this problem out for you. The MDF or Plywood does not need to be very thick anything between 3 - 5mm should do the trick.

 
This image shows three lengths of MDF sheets bridging the arched slats and central bar to prevent the central dipping problems. They are also not so big as to prevent any problems with aeration to the mattress.  Please see our video below which will provide you with further information on this subject :-
 

 
I would also recommend adding a mattress topper to your current mattress to add extra comfort layers due to the fact that you could feel the central support of your base through the mattress.  This topper will also protect your mattress at the same time.

I hope this assists however should you require further information please ring the office and speak to one of our friendly team - 0161 437 4419.
 
Kind regards
Julie