The present invention refers to a method of the type described in the preamble of claim 1 for laying a floor in a wet room.

When laying a floor in a wet room, i. e. one where there is a risk of water spillage, such as in bathrooms and toilets, and rooms where clothes washers have been installed etc., it is necessary to keep water from seeping through to floors below and/or to a supporting structure that can be damaged by water leakage.

To achieve the desired waterproofness in such floors, a barrier layer in the form of a membrane made of a suitable water impermeable material, such as a PVC film, is used.

The use of such membranes in Norway is governed by"Wet room norms for bathrooms etc." A properly laid floor will remain waterproof (water imper- meable) as long as the membrane is undamaged. However, when installing fixtures such as toilets, wash basins with pedestals, bidees etc. , the underlying membrane risks being punctured when holes are bored for an anchor bolt. A punctured membrane represents a clear danger for the seep- age of moisture and resulting damage of the underlying sup- port structure or floor, which can lead to fungus infec- tion, corrosion and other kinds of damage.

The present method will essentially prevent damage of the underlying membrane when bolt holes are bored in a wet room floor already laid.

Use of the present method largely eliminates the danger that the membrane will be damaged during the boring operation.

The laying of a wet room floor in accordance with the present method includes the laying of a membrane film, (made of PVC, for example) in the usual way on a supporting floor. If heating cables are laid, a 2-4 cm thick marking plate is applied at the places/places where bolts are fastened, along with concreting (if needed). Subsequently, a 3-5 cm thick top concrete layer, is applied. If heating cables have not been laid, the membrane is covered with a 5-8 cm thick concrete layer. The floor may be painted, a vinyl coating may be applied, or tiles may be fitted, depending on the wet room's intended use.

The method is unique as specified in claim 1's characteriz- ing part ; additional features are mentioned in the dependent claims.

The plate which is placed over the membrane can be made of plastic, such as polypropylene, polycarbonate, or poly- ethylene (or a suitable alternative plastic substance), or of rubber or metal. The material used in the plate should be of such a nature that the one who is boring will notice right away when he has bored all the way through the con- crete flooring. The plate should preferably have a thick- ness in the range of 0. 5-10 mm, depending on the choice of materials ; for a metal plate, the thickness can range from 0. 5-1. 5 mm (0. 8 mm, for example). The invention will be described in greater detail in reference to figures 1-3.

Fig. 1 shows a wet room floor laid according to a familiar technique ; fig. 2 shows a floor with heating cables, laid in accordance with the present method ; fig. 3 shows the schematic structure of the wet room floor, without heating cables.

In figures 1-3, the same reference numbers are used for corresponding parts.

In fig. 1, which shows a conventionally laid floor, the parts are specified as follows : 1 : the supporting floor ; 2 : a membrane ; 3 : indicates the heating cables (it goes without saying that the heating cables should not be locat- ed where fixtures are installed, because this risks ruining the heating cables) ; 4 : shows the concrete layer 1, which is needed to hold the heating cables in place ; 5 : designates concrete layer 2, and 6 : designates the floor- ing, such as vinyl covering or tiles.

Fig. 2, which shows a floor laid in accordance with the invention, is largely identical to fig. 1, except that between membrane 2 and concrete layer 1, a marking plate 7 is inlaid.

Fig. 3 shows a perspective picture of a part of a wet room floor laid in accordance with the present method, and shows a supporting floor 1 with a subsequently laid membrane 2.

Thereupon a marking plate 7 is applied, a concrete layer 2, and finishing flooring 6 ; the parts marked 7,5 and 6 are shown bent for the purposes of illustration, but it must be understood that these parts essentially represent stiff, non-bendable parts.

The plate used in the present method should preferably be made of metal and, in order not to damage the underlying membrane, it should have rounded corners and edges. Before the plate is placed on the membrane, it is advisable to apply a two-sided self-adhesive tape to the side that will be facing the membrane, so that the plate will not be moved out of place when the concrete flooring is applied.

The plate can be applied in advance with one or more strips of self-adhesive tape, covered with a removable strip to

prevent sticking together during transportation and handling.

The use of the present method completely eliminates the danger of puncturing a moisture barrier in the form of a water impermeable and moisture impermeable membrane when boring in concrete at those places where fixed installa- tions are being installed in the wet room. The invention also includes the use of such a plate in the application of the method. It goes without saying that the plates may be of various shapes and sizes, depending on the form and size of the fixture to be bolted fast to the underlying layer.