distance a is related to two adjacent support feet of a diagonal row said distance at least equals the diameter d o of the inner circle at the open end of the support foot so that the deformation areas 10 have a surface sufficient enough to allow deformations of said deformation areas for height adaptation of the support feet to an uneven ground yet the distance a must not be larger than 75 mm since a person walking on the floor sheet could be in danger of sinking in between two support feet the width of a grown up 39 s shoe heel is about 80 mm such a heel cannot sink into a support foot 11 fig3 shows a cavity floor with a heat insulating layer 17 arranged on the underlying ground 16 e g a raw concrete ceiling on which the floor sheet 15 of fig1 and 2 stands support feet down the lime floor 18 which will constitute the floor surface has been spread on the floor sheet 15 said lime floor fills the support feet 11 completely and develops an additional continuous layer on top of the horizontal area 10 to spread the lime floor 18 the floor sheet 15 previously laid loosely on the insulation layer 17 is capable of bearing the weight of a walking person without auxiliary load distributing means the floor sheet can also be used in the opposite way i e with the support feet up nor is it necessary to use the floor sheet as a mould for.