referring to fig1 , a subsection 10 of a full contact floating roof of the present invention is shown . the subsection 10 is comprised of four square angle parallelepiped buoyant cells 12 , which are joined together by joins 14 . thus , the width 16 of the subsection 10 will be essentially four times the width of each buoyant cell 12 , and the length 18 will be essentially the length to which the buoyant cells have been cut . because it may be convenient to pre - assemble subsections 10 away from the final construction site , the length 18 of the buoyant cells 12 can be determined by factors such as total weight of the subsection 10 , shipping size limitations , or the dimensions of the overall roof to be constructed . in the preferred embodiment , the subsection 10 is provided with a frame 20 which around the perimeter of the subsection 10 , allowing for increased structural integrity for the subsection 10 , and allowing for easy attachment of lift points 22 to the subsection 10 . if one or more of the sides 24 of the subsection 10 will be in contact with the sides of the fluid containment tank ( not shown ) in which the floating roof will be installed , a primary 26 and secondary 28 seals are preferably attached to those sides 24 . to facilitate removal of excess loads , such as rainwater , drains 30 may be inserted through one or more of the buoyant cells 12 , and sealed in place with adhesives to prevent leakage around their perimeter . referring to fig2 , an end view of four buoyant cells 212 , assembled as in fig1 , is shown . each buoyant cell 212 comprises risers 214 which extend the length of the buoyant . cell 212 , forming essentially independent sub - cells 216 . in the preferred embodiment , formed strips of rigid or semi - rigid material 218 fit into extruded , gripping slots ( see fig3 ) in the sides of the buoyant cells 212 , positioning the buoyant cells 212 in a tightly held relationship to each other . adhesive ( not shown ) is additionally used in each of the joins 219 , to further strengthen and seal the bonds between the buoyant cells 212 . the sides 222 of the subassembly 210 comprise a frame 220 , which is preferably formed of fiberglass or frp with an extension 224 which fits into the extruded , gripping slots ( see fig3 ), and is preferably bonded further to the respective buoyant cell 212 with two - part urethane , preferably pliogrip . referring to fig3 , an end view of the extruded , gripping slot in the side of a buoyant cell 312 of the preferred embodiment is shown . the slot 314 is formed by extrusion so that a formed rigid or semi - rigid strip 316 can be securely slid into the slot 314 , so that adjacent buoyant cells may be securely joined together . as those of skill in the art will recognize , other means of attachment of the buoyant cells is feasible , such as using bolts or screws , or using bridges secured to the top or bottom surface of the buoyant cells . accordingly , this depiction of the preferred embodiment of the extruded , gripping slot 314 is for illustrative purposes only , and is not intended to limit the scope of the invention . referring to fig4 , one method of joining two subsections such as that of fig1 is shown . the frames 410 , 412 of the respective subsections 414 , 416 are positioned so that a gasket , preferably a self - stick gasket 418 can be placed between them to form a seal , and toggles 420 can be positioned at appropriate intervals down the length of the frames 410 , 412 to securely tie subsections 414 , 416 together . thus , any number of subsections 414 , 416 can be assembled side - to - side or end to end , as necessary to form the needed area for the full contact floating roof . referring to fig5 a , 5 b , and 5 c , various configurations of the interior of the buoyant cell 510 are shown . the sub - cells 512 may be filled with a gas through valves ( or , alternatively , couplings ) 513 , such as an inert gas ( not shown ) to increase the fire - resistant qualities of the buoyant cell 510 . similarly , the interior walls 514 of the sub - cells 512 may be coated with an intumescent material 516 to provide fire - proofing , or , in the case of a puncture of the buoyant cell 510 , fire - suppression . this coating can be easily accomplished by inserting a hose ( not shown ) with a spray attachment ( not shown ) down the length of the sub - cell 512 , then spraying the intumescent material 516 while withdrawing the hose . further , fluid or gas probes 518 may be inserted in each sub - cell 512 for leak detection purposes , and may be placed in signal communication with a detector ( not shown ) by providing a signal lead 520 through a hole 522 ( or slot , if at the end of the buoyant cell ) in the walls 514 of the sub - cells 512 . sealant or adhesive ( not shown ) may be placed around the signal lead 520 where it penetrates the walls 514 to insure the continued separation of the sub - cells 512 . the signal lead 520 can then be extended through the top 524 of the buoyant cell 510 . as those of skill in the art will recognize , signal leads could be extended from each sub - cell 512 rather than being joined in a single feed , without departing from the spirit of the invention . however , using a single feed reduces the number of penetrating holes in the top 524 . referring to fig6 a and 6b , multiple configurations of the seals for the ends of the buoyant cells 610 are shown . each sub - cell 612 is sealed with a block 614 of material such as valox , which is permanently set in place with adhesive . if the shape of the roof is round or oval rather than square , or even an irregular shape , the ends of the buoyant cells 610 may be cut to shape as needed , as shown in the example of a circular floating roof section of fig6 b . the sealing blocks 614 can then be cut to the shape of the end of each sub - cell 616 , as needed . however , if the ends of adjacent sub - cells are sufficiently straight , a single block 614 of material may be used to bridge and seal the ends of more than one adjacent sub - cell ( not shown ). those of skill in the art will recognize that variations of the above description may be made without departing from the scope and spirit of this invention , and this invention shall not be unduly limited to these illustrative embodiments .