MOVABLE CONCRETE FOUNDATION, MOVABLE BUILDING, AND METHOD FOR MANUFACTURING CONCRETE FOUNDATION FOR MOVABLE BUILDING

TECHNICAL FIELD OF THE INVENTION

The invention relates to a concrete foundation and a method for manufacturing the same as well as to a movable building with a concrete foundation and sewage piping that are disclosed in the preambles of the independent claims presented below.

PRIOR ART

In the field of building detached houses, it has been moved from the traditional on- site building towards prefabricated building, whereby only the installation of the elements takes place on the building site. Even in prefabricated building, the trend is towards increasing the grade of prefabrication of buildings, whereupon the amount of the building work to be performed on the working site further decreases. In the furthest developed solutions of prefabricated houses, a detached house is built together with its foundation entirely ready at the factory and delivered as a ready house to the site, where it is lifted to its place for example on a levelled gravel bed.

Even though the previously described way of building and erecting a prefabricated house with a foundation reduces considerably the work to be done on the building site and speeds up the taking into use of the building, there still is some installation work to be done before the building is entirely ready for moving in. Such necessary works to be done on the building site are connecting the building to electricity, water and sewer networks. Especially, connecting to sewer network is sometimes problematic and slow. On all sites, there does not even exist centralized municipal sewer network, whereby an own individual sewage treatment system has to be built to the site. Depending on the soil and groundwater conditions of the building site, such system may comprise emptiable closed containers, septic tanks, biological and/or chemical small-size purifying plants and filter fields.

OBJECT AND BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to reduce or even eliminate the above- mentioned problems appearing in prior art.

It is an object of the present invention especially to provide a movable concrete foundation and a movable building with which the drawbacks and disadvantages related to sewage treatment of buildings may be reduced.

In order to realize the objects mentioned above, among other things, the concrete foundation, building and method according to the invention are characterised by what is presented in the characterising parts of the enclosed independent claims.

The embodiment examples and advantages mentioned in this text are in suitable parts applicable to as well the concrete foundation, the building and the method according to the invention, even if this is not always specifically mentioned.

A typical concrete foundation according to the invention is made of reinforced concrete. On the foundation, a building, for example a residential building, is typically built. The foundation is ready-built at the factory and transported as a uniform ready construction to the building site, i.e. the foundation is a movable concrete foundation. At least one sewage treatment unit to be connected to the sewage piping of the building to be located on the foundation ¹ has been integrated to a typical foundation according to the invention, by means of which unit the treatment of the sewage generated in the building is taken care of. This sewage treatment unit may be an emptiable closed container, an emptiable septic tank, a chemical purification unit, a biological purification unit or any other treatment unit suited for the purpose. One or several, for example 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 to 5, 2 to 10 or 5 to 10, treatment units may be integrated to the one and the same foundation. A movable foundation according to the invention may form the foundation of the building to be built thereon in its entirety or it may form only a part of the foundation of the building.

A typical method according to the invention for manufacturing a concrete foundation of a building in a casting mould comprises at least the following stages:

- mounting necessary piping and wiring inside the mould,

- placing one or several sewage treatment units and the piping required by them inside the casting moulds, whereafter

- casting concrete of the foundation.

The volume of a single sewage treatment unit according to the invention may be for example 0.1 to 10 m ³ or 0.2 to 4 m ³ or 0.3 to 1 m ³ .

By sewage piping is meant piping intended for transferring water needed in the building, especially the piping intended for transferring used water. In a building and a foundation according to the invention, there may be several sewage pipings that are separate from each other and intended for different water types. Different water types, of which one or several may have their own pipings or a piping shared with one or several other water types but separate from others, are for example clean drinking water, so-called graywater, treated graywater, rain water, treated rain water, excrement-containing water and treated excrement-containing water.

In an embodiment of the invention, at least one treatment unit has an inlet connection for connecting the treatment unit to the sewage piping of the building. At least one treatment unit may have an outlet connection for leading the sewage out of the treatment unit. At least one treatment unit may have a discharge connection for emptying the treatment unit. The discharge connection may for example be made suitable for a suction hose of a pumping truck.

In another embodiment of the invention, there are more than one treatment units, and the treatment units are connected to each other with a connecting pipe. This enables a multi-stage treatment of sewage.

In a typical movable building according to the invention, there is a concrete foundation according to the invention and sewage piping. At least one sewage

treatment unit connected to the sewage piping of the building is integrated to the foundation of the building for treating the sewage generated in the building. Said sewage treatment unit may be for example a closed container, a septic tank, a chemical purification unit or a biological purification unit.

In an embodiment of the invention, the movable building is by its internal and external structures a prefabricated house substantially ready-built for example in a house factory. In an embodiment of the invention, the building forms only a part of a building.

In an embodiment of the invention, only the concrete foundation according to the invention is manufactured in a house factory or the like. In that case, the end-user that has bought the foundation can build on the foundation the building he desires.

In an embodiment of the invention, the concrete foundation according to the invention and on it only a part of the ready-built movable building are manufactured in a house factory or the like. The building may for example be ready-built apart from the decoration work. On the other hand, for example only the frame and the roof of the building may be built in a house factory or the like.

An advantage of the invention is that it speeds up the process of bringing the building ready for moving in, because the sometimes problematic and labour- consuming connecting to the sewer network or the individual sewage treatment system can be handled later, e.g. after moving in.

A further advantage of the invention is that it considerably speeds up and facilitates the building of an individual sewage treatment system, because a considerable part of the treatment system is already integrated to the building. In this case, only the completion of the sewage treatment system readily present in the building with measures to be taken at the building site remains to be done on the working site. Such measures may e.g. be the building of a filter field, if needed. On areas where the sewage has to be collected to an emptiable closed

container, with the help of the invention, the excavation work to be done on the building site can be entirely avoided.

Yet another advantage of the invention is that by means of it, a part of the heat energy contained in the sewage and of the heat energy generated in the sewage treatment process may be utilized in the heating of the building, whereby savings are accrued as to heating costs. In an embodiment of the invention, the foundation according to the invention leads heat energy upwards to the floor surface of the building which heat energy may be directly utilized in the heating of the building.

In an embodiment of the invention, the foundation comprises special heat exchange devices for transferring heat energy from the sewage treatment device to the interior of the building. For example a heat pump, known as such, recovering heat energy from the water may be placed to the sewage treatment unit. The heat contained in the sewage and the heat generated by the sewage treatment process are thus recovered and transferred to be used for the heating of the building, e.g. to be used in the hydronic floor heating. An arrangement of this kind typically comprises devices known as such, such as heat exchangers and a control unit.

In an embodiment of the invention, also rain water is utilized in the system, which water is collected to at least one sewage treatment unit. The rain water may usually be used directly for example as irrigation water. The rain water may also be purified in the system into service water, for example to be used in a shower or a tub. The rain water may be collected for example from the roof of the building by leading the water rained on the roof through gutters and down pipes to its treatment unit.

In an embodiment of the invention, used shower water and other so-called graywater generated in the building, for example from a bath tub, a swimming pool or a washing machine may be directed to one sewage treatment unit. The graywater may be treated and recycled for example as toilet flushing water. In

some cases, the treated graywater may be used as irrigation water, car washing water, or it may be released to the nature.

In an embodiment according to the invention, the water used in the toilet is directed to its own sewage treatment unit. This unit may be such that a tank truck fetches the sewage. Excrement-containing water may also be treated, and the treated sewage may be directed to the nature, through a filter field, if needed. Treated sewage may in some cases be used also as irrigation water or as car washing water.

In the foundation of a building according to the invention, it is thus possible to treat different kinds of waters in different sewage treatment units. It is possible to arrange for all or for some water types their own pipings that are separate from each other.

BRIEF DESCRIPTION OF THE FIGURES

The invention is described in more detail below with reference to the enclosed schematic drawing, in which

Figure 1 shows as an example a building according to the invention seen from the side, and

Figures 2a, 2b and 2c show as examples some embodiments of the foundation according to the invention seen from above.

DETAILED DESCRIPTION OF THE EXAMPLES OF THE FIGURES Figure 1 shows as an example a building according to the invention seen from the side. The building has a foundation 10 made of reinforced concrete, which foundation has a upper surface 12 and a lower surface 14. On top of the upper surface of the foundation, there have been built external walls 16 of a building and a roof 18 on top of them according a conventional method of construction. Inside the area delimited by the external walls and the roof, there are conventional internal structural parts belonging to a building, such as partition walls, a floor, a ceiling, inside doors, and fixtures, as well as heating, plumbing, ventilation and electrical systems. The building may be substantially ready-made by its internal

and external parts to a so-called prefabricated house or to the grade of readiness desired by the client.

In the building shown in Figure 1 , there are inside the foundation of a building, i.e. inside the area delimited by upper and lower surfaces 12, 14 and outer edge 11 of the foundation, sewage treatment units 20 integrated as a part of the foundation. In practice, the integration has been performed so that the treatment units 20 have been placed inside the casting moulds before the concrete of the foundation has been cast, whereafter the concrete has been cast to the mould. After the hardening of the concrete, the treatment units remain as an integral part of the concrete foundation. Naturally, also the reinforcement needed by the foundation, the sewage piping for the floor of the building and other possible piping and wiring needed by the technical systems of the house have been mounted inside the moulds before the casting of the concrete. However, these are not especially within the scope of the invention, thus they are not described further in this connection.

Sewage treatment units 20 are dimensioned so that their upper surface facing the room space of the building remains below the level defined by the upper surface 12 of the foundations and their lower surface facing the soil surface extends at most to the level defined by the lower surface 14 of the foundations. The lower surface of the treatment units is set in the ready construction a little above the level defined by the lower surface of the foundations. At their lateral surfaces, the treatment units are placed clearly apart from the outer surfaces of the foundations. Thereby after casting of the concrete, the treatment units become entirely surrounded by concrete at least at their upper surface and lateral surfaces. The concrete layer to be formed on the upper surface of the treatment units forms the floor slab of the building. The concrete shields the treatment units during the later building stages of the building and during transport and lifting of prefabricated houses. At the building site, the ready-made foundation may be safely laid onto a levelled gravel bed, because the loads of the foundations are transferred to the gravel bed via the concrete parts of the foundations without causing strains on the sewage treatment units. Before casting of concrete, the sewage treatment units 20

may be surrounded by a suitable insulation material, for example by polystyrene, expanded polystyrene or another insulator. In an application of the invention, the lower surface and/or the lateral surfaces of the treatment units 20 are insulated but the upper surface is not. In that case, the heat energy gets to move especially upwards, to the building above the foundation.

In a prefabricated house according to the invention, it is possible to use several different sewage treatment units 20. The choice of a suitable treatment unit may be done always case by case according to the client's wishes, the soil and/or groundwater conditions of the building site or the purpose of use of the building.

Figure 2a shows as a principle picture an embodiment of the foundation 10 of the building according to the invention seen from above. In the Figure, an outer edge 11 of the foundations is shown with a uniform line. Inside the area delimited by the outer edge, there are three closed containers 20a that form the sewage treatment system of the building. Each closed container has a discharge connection 22, the end of which extends to the outside of the outer edge of the foundation. At the end of the discharge connection, there is an openable lid 23. The closed containers are connected to each other with connecting pipes 24, through which the sewage may flow from one container to another. At least one closed container has an inlet connection 26 that is connected to the sewage piping 30 of the building. The sewage issuing from the sewage sources of the building, such as a toilet, floor drains, and basins, is directed along the sewage piping through the inlet connection 26 to the closed containers, 20 to which they are stored. When the closed containers are filled up, they will be sucked empty through discharge connections, and the sewage is transported to a sewage treatment plant for further treatment. The embodiment of the invention shown in Figure 2a is suitable for being used for example in building sites where there is no centralized sewer network and where it is not allowed to absorb the sewage to the ground.

Figure 2b shows as an example a second embodiment of the foundation of the building according to the invention. In the embodiment shown in Figure 2b, there are a number of second closed containers 20b in addition to the first closed

containers 20a. The first closed containers are similar to those in the embodiment of the Figure 2a, and excrement-containing sewage generated in the building are directed to them. The second closed containers may be similar to the first closed containers as to their structure, and the so-called graywaters, i.e. sewage other than the excrement-containing sewage, generated in the building is directed to them. The second closed containers are connected to each other with connecting pipes 24 as a queue. In the first closed container of the queue, there is an inlet connection 26, through which the "gray" sewage flows to the other closed containers, and in the last closed container of the queue, there is an outlet connection 32, through which the graywater may be directed out of the container. The outlet connection may be connected for example to a sewage filter field 100 built to the site, with which filter field the sewage is absorbed to the ground. The sewage in the second closed containers may also be used for example as irrigation water for lawns and plants in courtyard areas. The first closed containers to which only excrement-containing sewage is gathered are emptied at need e.g. with a pumping truck.

Figure 2c shows as an example a third embodiment of the movable foundation according to the invention. In the embodiment of the Figure 2c, the sewage treatment system integrated to the foundation comprises five treatment units that have been connected with connecting pipes 24 as a queue. In the first treatment unit 2Od of the queue, there is an inlet connection 26, through which the sewage flows into the units, and in the last treatment unit 2Oe of the queue, there is an outlet connection 32, through which the sewage is directed out of the units to a sewage filter field 100 built to the site. The three middlemost treatment units are septic tanks 20c in which the solid matters of the sewage are separated from the sewage water by depositing on the bottom of the septic tanks. The first treatment unit of the queue is a chemical purification unit 2Od, in which a chemical coagulant is admixed to the sewage in order to precipitate the nutrients that are in soluble form to depositing particles. The chemical purification unit typically comprises a chemical container for the chemical coagulant and a dispenser that are connected to the purification unit (the chemical container and the dispenser are not shown in the Figure). In an application of the invention, the chemical container and the

dispenser are placed outside the foundation inside the building for example to a service room in which the filling of the chemical container is easy. The last purification unit in the queue is a biological purification unit 2Oe, in which the biological purification of the sewage takes place by means of decomposer bacteria. In a biological purification unit, there may be filler material functioning as a substrate for microbes, such as plastic discs, as well as a sewage aerator (the filler material and the aerator are not shown in the Figure). Purifying the sewage chemically by means of a chemical coagulant and biologically by means of decomposer bacteria is prior art technique known as such that is used in several different individual small-size purifiers on the market, thus their structure and functioning are not described further in this connection. Septic tanks 20c are emptied at need, just as the closed containers.

The Figures 2a, 2b and 2c show some embodiments of the movable foundation according to the invention. It is clear to a person skilled in the art that sewage treatment units shown in them as examples may be combined and placed to the foundation in different ways. For example, the number of septic tanks and closed containers may vary, and the chemical and/or the biological purification unit may be arranged in connection with a septic tank. Nor is the invention limited solely to the use of the above-described treatment units but any kinds of suitable sewage treatment units, such as different filters, may be used in it.

A movable concrete foundation according to the invention is ready-made at the factory, and on top of the foundation, a building is built at the factory. The building may be manufactured to any grade of readiness desired by the client, such as to a so-called cover from weather stage, to be ready for decoration or to a prefabricated house substantially entirely ready at its internal and external parts. The foundation and the building on top of it are transported as one complex to the building site and laid to its place for example on a levelled gravel bed. After this, connecting to the electrical and water supply networks as well as eventual supplemental installation and building work of the sewage system are performed, whereafter the building is ready for moving in. The foundation according to the invention may also be transported solely to the building site after manufacturing,

whereby the building to be built on top of the actual foundation is built only at the building site.

Some embodiments of the movable concrete foundation and the building according to the invention have been described above. The invention is not limited to the solutions described above, but the inventive idea can be applied in numerous ways within the scope of the claims. The Figures do not specifically show matters that are secondary in view of the main idea of the invention, known as such or obvious as such for a person skilled in the art. The dependent claims present some possible embodiments of the invention, and they are not to be considered to restrict the scope of protection of the invention as such.