You should try making your own custom fills they are really quiet easy and fun to make .
Draw your patten with lines, circles etc etc. Simply copy them to the clipboard. Under options/fill types duplicate an existing fill, making sure you set it to symbol fill and then past in your elements that you created from the floor plan..
You may need to play around with some of the settings to get it exactly right. Once you are done simply choose the fill you have just created..
HTH.
Cheers.
Ben