Abstract: The aim of the invention is to provide a shower floor element and a shower floor construction, which permit an extremely simple, cost-effective production, in particular in situ and/or a more reliable sealing system in relation to prior art. To achieve this, a waterproof film is applied to the upper face of a support element consisting of a hard expanded plastic with a relatively high density of approximately 100 g per cubic decimetre or more and is sealed to said support element. This enables the pre-fabrication of a shower floor element, so that during the installation in situ a tile covering or other covering can be directly applied to the film. If a suitable material is selected, said film can also be welded to the support element. Preferred connection methods are bonding or welding. Depending on the material, a shrinking or deep drawing process can also optionally be used, or a negative pressure can be produced between the film and the support element, causing the two materials to adhere to one another.