Field of the Invention

The present invention relates to a device for drainage of the foundation wall in houses and building constructions.

Background of the Invention

As a single factor, humidity is probably the biggest problem we have in relation to indoor environment. Humidity is conditional for life and growth of many bacteria, fungi and other microorganisms that break down organic matter. Most building materials consist of organic matter. Besides constituting a constructional problem upon attack from decaying fungi, mould, algae and dust mite thriving in humid climate will be the cause of allergies and other oversensitive diseases.

Humidity also has large consequences for inorganic matter. Humidity in concrete support may for example lead to breakdown of softeners in plastic floor coverings. When plastic material is broken down due to humidity, foul-smelling gases are released (for example 2-ethylhexanol). Additionally, almost all materials which release chemical substances to the air will obtain increased release when the humidity contents are increased.

The ground around the building that has its floor below ground level must be drained if the ground is not self-draining.

Normal outer walls against terrain do not normally have density or strength to resist water pressure. At the outside of the wall there must therefore be a pressure-reducing and draining layer of crushed stone, gravel or sand, which prevents development of water pressure against a wall and which ensures conducting the water unhindered into the draining pipe. Special drainage sheets or drainage mats can be used when the ground is suited for this. Also, the walls below the terrain must have a water-resistant surface.

Drainage pipe is laid around the foundation wall. Where the ground is self-draining, for example where the ground below and around the building consists of gravel or blasted stone and the water has free drainage through the ground to ground water at the lower level, the draining pipe may be omitted. The drainage pipe should be surrounded by draining mass and be protected against mudding from overlaying soil masses.

When a traditional drainage system for a foundation wall is put into place, a drainage ditch is usually dug along the ring of the foundation wall in advance, whereby the bottom of the ditch is level with the foot of the ring of the foundation wall and level with this. Then a button designed sheet is usually first attached to the concrete wall itself which has the purpose of ensuring venting for the concrete wall, before putting drainage pipes in the bottom of the ditch, as close to the wall as possible. In this manner, water will be prevented from being in contact with the wall and from possibly forcing its way through this; instead, the water flows further downwards and is collected in the bottom of the ditch where it is conducted away with the aid of the drainage pipe, which is perforated in order to let the water in.

However, problems may arise when backfilling draining mass into the foundation wall. If there are coarse stones in the mass, they may easily rupture the button designed sheet, and otherwise lay against the concrete wall and in time this will be damaged. Further, occasionally some of the ditch wall may collapse, with the consequence of mixing soil with the drain mass. In practice it is not possible to restore this, i.e. by taking mass up again. The ditch must necessarily also be relatively wide, which means that a substantial amount of mass must be transported, more than what is required for the drainage. This increases the cost for the building, both in that the mass itself has a cost and in that there is an increased need for transportation.

To avoid this, several so-called drainage cases are described in patent literature. Common for all these is that they are placed on the outside of a foundation wall, and that they are provided with channels which may be filled with drainage mass of different form, size and type. It is also usual for such drainage cases to be in connection with drainage pipes at the underneath side of these. When the drainage case is mounted it can be filled with normal mass on the outside from the site into the case. This involves a substantial saving in the amount of mass which has to be transported to the site.

It is also known, for example from SE 446998 B, where it is demonstrated that such draining cases shall ensure the correct amount of relevant drainage mass and that mixing of other mass into the drainage mass is avoided. The technology in said patent comprises two layered rolls which constitute drainage case walls for the side which is facing towards the foundation wall and that side which is facing towards the ground, respectively.

The two layers are connected to each other with intermediate walls, such that they shall appear as four-walled vertically-erected channels when unrolled, which are open in both ends, and placed side by side on pre-laid drainage pipes into a foundation wall in a longitudinal direction around this.

When the roll is rolled out as a first lowermost shift along the foundation wall, it is cut and drainage mass is put into this, before in a corresponding way a new shift is started on top of this by connecting to the first shift in a lip on the longitudinal edge, rolling out again and filling drainage mass here too. In this manner, the process is continued until the foundation wall is covered in its complete height around the circumference.

Common for all the known solutions is that they comprise many parts which must be mounted at the building site and that they are bulky during transportation and difficult to mount on the building in a satisfactory manner.

Summary of the Invention

It is a purpose of the invention to provide a system and a device for drainage, i.e. a drainage case of the above-mentioned type, which avoids the disadvantages of known cases, and is far more practical in use.

This is achieved by a system and a device according to the attached patent claims.

Short Description of the Drawings

For an easier understanding of the invention, a further description of the invention will be given, with reference to the attached drawings, where:

Figure 1 shows mounting of sheet elements to the foundation wall before closure,

Figure 2 shows completed mounted elements after closure,

Figure 3 shows the constructive details in a drainage system according to the invention. Further Description of the Invention

Figure 1 shows a foundation wall (upper) where mounting of a drainage system is to be carried out according to the invention. The foot and the concrete wall itself are covered separately here. As the lower detailed drawing shows, the system consists of elongated drainage cases 1 with trapezoidal cross section, which are placed next to each other until the wall is covered. The opening between the drainage cases 1 is covered by a joining sheet 11. The corners have separate solutions, and the figure shows two different alternatives: at the base a separate corner case 13 is used. At the wall above is shown an angle-formed corner plate 14 covering the connection between two drainage cases which meet at the corner. At the bottom of the drainage cases holes are arranged for conducting drainage pipes 15. When the system is mounted, suitable drainage masses are filled into the drainage cases, whereupon the top side of the cases are covered with top lids 12. Figure 2 shows the finished system ready for filling of other mass on the outside.

Figure 3 shows details of the components which are included in the inventive drainage system. The drainage case 1 is shown in section and profile and consists of two inclined side walls 2, 3, a front wall 4, and possibly a rear wall 7. The front and side walls are equipped with perforations or openings 8 which let water through. The openings 8 can be in the form of holes or slits. The holes can be of any form, but are preferably circular. Further, in the lower end of the side sheets, hole 10 is formed for introduction of drainage pipes.

The drainage cage 1 is preferably equipped with a rear wall 7 in the form of a button designed sheet (foundation wall sheet). This saves time in that the case and the button designed sheet are mounted in one operation. However, the case can also be without rear wall, in case the user prefers to install a fully covering button designed sheet on the wall before the case is mounted.

Along the edges of the drainage case 1 there are flanges 5, 6 which allow the case to be fixed to the concrete wall with nails or any other suitable attachment means. Several drainage cases are mounted side by side such that the flanges overlap. The flanges can also be equipped with screws, allowing adjacent cases to be mounted tightly into each other, or even hooked tightly to each other.

The drainage case can be made of metal or plastic, i.e. preferably such that the front and side walls are made in a rigid material in sheet form, while the rear wall is made of standard button designed sheet in plastic. In the metallic version, the case can be made of pressed steel plates or of extruded aluminium. Plastic is, however, preferred due to costs.

The drainage system also comprises a connection plate 11. When two cases are mounted side by side, the plate 11 is eased into groove 9 formed in the corners of the cases. Plate 11 can also tie the cases to each other, if it is arranged to be locked in the grooves 9. Alternatively the plate can also be put into the groove in one of the cases, pivoted in to the other case and then be attached with clips, screws, nails or any other fastening means. The connection sheet 11 is also equipped with drainage openings 8.