WATER TIGHT FOUNDATION WALL SHEET WITH A FILTER CLOTH

The present invention relates to a watertight foundation wall sheet for use as a watertight layer between or on the outside of vertical building constructions, such as a foundation wall. Watertight foundation wall sheets are of the type, which on at least one side, preferably are formed with a pattern such as grooves, studs or projections configured to allow water or dampness to run downwards, and where the foundation wall sheet is preferably equipped on at least one side with a filter cloth preferably of a type which allows water to pass through whilst particulate material is held back.

It is already known to equip a foundation wall sheet with studs, projections and/or grooves. The purpose of these is to ensure that water can run down without coming into contact, in any degree worth mentioning, with the building construction behind. The applicant's own Norwegian patent No. 315,282 is referred to as an example .

It is further known to cover the side of the foundation wall sheet equipped with projections, studs or grooves with a filter cloth. A foundation wall sheet of this type is applied by letting the side of the foundation wall sheet equipped with studs and filter cloth face away from the building construction and outwards towards the backfilling.

It is also standard practice to lay a drainage pipe at the foot of the building construction to drain away water which has come through the ground, ground water or water from the surrounding ground. Drainage pipes of this type are preferably covered with graded material such as gravel or crushed stone. To avoid undesirable sand, earth or clay getting into the drainage pipe it is usual, in addition to the previously mentioned gravel or

crushed stone, to cover the drainage pipe with a loose filter cloth which is laid over the graded material by rolling out the cloth from a roll, the axis of the roll being orientated more or less across the lengthwise direction of drainage trench.

When laying the filter cloth in this traditional fashion it is often difficult to achieve a proper protection against the intrusion of material into the drainage pipe since uncovered areas can easily be formed, over or around the drainage pipe.

Having first to lay down a loose filter cloth and then place a filtering material under and over the drainage pipe before finally covering this with filter cloth down in a narrow drainage trench is a difficult task. This is further complicated by the depth and the uneven sides of the trench. The quality of the cover can also vary considerably unless the trench is made extra wide .

One object of the invention is to produce a foundation wall sheet which in a simple and cost effective way can be applied to a building construction.

A second object of the invention is to secure a good and effective draining of ground water, seeping water and any other dampness which might come through the ground.

A further object is to provide a solution which ensures that the drainage remains effective after completion of the drainage work in that later blocking of the drainage pipes is effectively prevented.

The objects of the invention are achieved by a foundation wall sheet defined in the characterizing part of the independent claims, seen in the light of the introductory part.

Possible embodiments of the invention are further described in the dependent claims.

Two preferred embodiments will now be described in

more detail with reference to the Figures where:

Figure 1 shows a vertical section of a foundation wall sheet according to the invention, provided with a folded filter cloth or flap temporarily fastened to the foundation wall sheet;

Figure 2 shows the same section as shown in Figure 1 but after the folded filter cloth's or flap's upper edge is loosened from the foundation wall sheet ready to be laid round the drainage pipe;

Figure 3 shows schematically a vertical section through the preferred embodiment of the invention fixed to the lower part of a building construction prior to the positioning of the drainage pipe and filling of drainage material;

Figure 4 shows schematically the embodiment shown in Figure 3 after the folded filter cloth is wrapped round the drainage pipe and the drainage material has been filled in the trench;

Figure 5 shows schematically a vertical section through another embodiment of the invention equipped with a split folded filter cloth fastened to the lower part of the building construction before the laying the drainage pipe, prior to filling the drainage material;

Figure 6 shows the embodiment shown in Figure 5 after laying the drainage pipe and positioning the folded and split filter cloth material;

Figure 7 shows schematically a vertical section through a third embodiment equipped with a creased folded filter cloth prior to the laying of the drainage pipe;

Figure 8 shows schematically the embodiment shown in Figure 7 after the folded filter cloth is folded out, the drainage pipe has been laid and the draining material has been filled in the trench.

In the following description the same reference numbers are used for the same construction details.

Figure 1 shows a section of a foundation wall sheet 10. The foundation wall sheet 10 is of a type formed of a plastic foil 12 equipped with rows of studs 13. The whole side of the foil 12 where the studs 13 project outwards is covered with a filter cloth 14 (not shown in Figure 1) . The foundation wall sheet 10 is supplied in continuous lengths in rolls, rolled up along an axis parallel to the vertical edges 16. At the lower end an extra fold or flap 15 of filter cloth is provided 15. This fold or flap 15 is fastened to the filter cloth and to the studded side of the sheet 14 by either welding or gluing to a few of the studs 28. Alternatively the fold 15 can be fastened temporarily to the cloth 14 or the foil 12 using a "velcroue" system (not shown) . The folded filter cloth 15 can be made of one piece which has its upper edge temporarily fastened to the filter cloth 14 behind it by, for example, spot welding, spot gluing or by using a "velcroue" system. Alternatively the fold or flap 15, can be fastened to the filter cloth or plastic foil at an upper crease 17 placed, more or less in the middle of the fold or flap 15, the fold 15 being temporarily fastened to the filter cloth and plastic foil at the crease 17 on studs 28. The flap or fold 15 making the outermost part of the fold 15, can either be folded so that the free end lies inside or outside the remaining part of the fold. Other preferred embodiments of the folded filter cloth are described below with reference to Figures 3, 5 and 7.

Figure 2 shows a corresponding section of the foundation wall sheet as shown in Figure 1 but where the fold is drawn out. As shown in Figure 2, the fold is consequently only fastened to the filter cloth and plastic foil at its lower edge whilst the opposite end of the fold is free.

Figure 3 shows schematically a vertical section through the lower part of a building construction 11.

The building construction, as shown, consists of a slab or floor 18 and a foundation wall 19. The slab 18 protrudes beyond the wall 19. Insulation material 21 is applied to that part of the wall which is expected to lie under the surrounding ground 20 and rests on the jutting out portion of the slab 18. A membrane 22 can be arranged between the insulation sheet 21 and the wall 19. This membrane 22 can be in the form of a plastic foil or an sealing material applied to the wall. The insulation sheet 21 is fastened to the wall 19 by means of suitable fastening materials or devices such as plugs 23, bolts or other similar fastening means. Alternatively the insulation sheet can be glued into place using any suitable method.

A foundation wall sheet 10 according to the invention is fastened to insulation sheets 21 by means of conventional fastening means, such as plugs, bolts 24 or similar. The foundation wall sheet 10 is of the well- known studded type, where the side of the sheet intended to face outwards towards the back fill material, is covered completely with the filter cloth 14. According to this solution the studs also face outwards so that water and dampness which may get to the foundation wall sheet 10 are allowed to drain vertically down on the foundation wall on the wall sheet's outside. The filter cloth 14 is of such a type and made from such material that water can pass through the filter cloth 14 but other material and particles are held back. The filter cloth 14 extends in the whole height of the foundation wall sheet 10 and is permanently fastened to it by gluing or welding. At the upper end of the insulation sheet 21 a top profile 25 is installed, covering the upper end of the assembly, preventing water, dampness and any loose matter from entering between the insulation sheet 21 and the foundation wall sheet 10.

As shown in Figure 3 a drainage pipe 26 is installed

at the base of the building construction 11. Such pipes should preferably lie at a level under the slab or floor 18. The drainage pipe 26 is surrounded by drainage material 27. This drainage material 27 is also filled up against the filter cloth 14 and the foundation wall sheet 10. Ordinary back fill 20 or earth is filled up on top of the drainage material 27.

The embodiment shown in Figure 3 is of the type where the folded filter cloth consists of a single flap. This is laid over and partly round the drainage pipe 26. As is shown in the Figure the bottom end of the fold is permanently fastened to the foundation wall sheet 10 whilst the other end is free.

Installation of the foundation wall sheet is made in the following steps :

Firstly, the foundation wall sheet 10 is fastened to the building structure 11 using plugs 23 with the fold temporarily hung up on the foundation wall sheet 10. A layer of drainage material 27 is then laid round the building structure 11, there after the drainage pipe system 26 is installed and covered by more drainage material 27. The end of the folded filter cloth is then loosened from the foundation wall sheet and laid over the drainage material 27, the installation is then back filled in the usual way.

Figure 4 shows schematically the form of installation shown in Figure 3 after the folded filter cloth 15 has been placed over the drainage material 27, lying below and over the drainage pipe 26.

Figure 5 shows an alternative embodiment of the invention. For the sake of clarity the back fill material 20 is not shown. This embodiment is in many ways similar to the one described in connection with Figure 3. According to this solution the folded filter cloth 15 consists of two separate flaps 15 which are fastened along one edge to the foundation wall sheet's

10 lower edge and which, at the other edge, are temporarily fastened to the filter cloth 14 at some few spots 28. As shown in Figure 6, the two flaps are not fastened to each other along the top edge 15.

Figure 6 shows the foundation wall sheet as installed. As shown, the first step is to lay a pillow of drainage material 27, thereafter the outside flap 15 is loosed from its fastenings 28 and laid over the drainage material 27. The drainage pipe is then laid and covered with drainage material 27. The second flap is then released and laid over the drainage material covering the pipe. When this second flap is in place further drainage material and back fill can be applied as described in Figure 4.

Figure 7 shows schematically a further preferred installation form where the folded filter cloth 15 is in the form of a creased fold. The creased fold 15 is permanently fastened along its lower edge to the foundation wall sheet's lower edge whilst the other edge of the folded and creased filter cloth 15 lies against the filter cloth 14. This free edge can be temporarily fastened using a "velcroue" system (not shown) where the one part of the system is fastened to the free end of the flap whilst the other part is fastened just above the permanent fastening of the other edge to the bottom of the foundation wall sheet. The upper end of the fold is still temporarily fastened to the foundation wall sheet 10.

With this placing of the "velcroue" system it can also be used to fasten the folded filter cloth' s free end after it has been laid round the drainage pipes 26.

Figure 8 shows schematically the installation form shown in Figure 7, but in installed position. According to this form of installation a bed of drainage material 27 is first laid. The folded filter cloth 15 is then loosened, laid over the bed of drainage material and up

along the side of the trench. Thereupon a second layer of drainage material 27 and the drainage pipe 26 is laid on top of the filter cloth, while a third layer of drainage material is laid on top of the pipe and the whole is then covered by taking the free end of the folded filter cloth 15 back over the installation and preferably fastening this using the "velcroue" system already in place. A forth layer 27 of drainage material is then laid on top of the filter cloth 15, whereupon backfill is filled in a conventional manner.

Although one of the shown embodiments is provided with two folds 15 having the same length, it should be appreciated that the outer fold 15, i.e. the fold 15 intended to be placed beneath the drainage pipe 26 and the drainage filling 27 may preferably be longer than the inner fold.

Further, it should be appreciated that the folds on a visible part may have numbers or laying instructions added, indicating the sequences to be followed when loosing the folds. The instructions may either be in the form of numbers or in the form of text and/or figures .