US20080155937A1

US20080155937A1 - Method for Building Houses

Info

Publication number: US20080155937A1
Application number: US11/578,747
Authority: US
Inventors: Fredrik Sontum
Original assignee: Individual
Current assignee: Selvaag Spinoff AS
Priority date: 2004-04-21
Filing date: 2005-04-21
Publication date: 2008-07-03
Also published as: NO20041615D0; NO322390B1; WO2005103402A1; NO20041615L; EP1747327A1

Abstract

In a method for making a house, a foundation plate (1) consisting of a lightweight concrete is cast directly; on a drained and leveled substratum such that it extends a distance (a) outside the external walls of the house. Grooves (2) are milled in the foundation plate (1) where prefabricated wall elements (5-8) later are to be erected, where the bottom of the grooves is exactly horizontal and at the correct level. Next, prefabricated wall elements (58) are placed into the respective grooves (2) and glued to each other and to the foundation in the grooves. The wall elements have a height which is about 45 cm larger than the inner roof height of the house in order to facilitate the casting of a sub-floor of lightweight concrete inside the house once pipes and conduits for sanitary and electrical installations have been laid, and after parts of the walls (5-8) which have been cut out to provide openings (3, 4) for doors and windows, have been placed on the foundation plate (1). Any floor heating or floor finishing is placed on the sub-floor. The house is provided with a roof (10, 11) which comprises roof elements, which also are made from lightweight concrete and are provided with tensile reinforcement. The lightweight concrete used may comprise EPS spheres, cements, additives providing adhesion between the EPS spheres and the cement, and the water. Through this method the cost of erecting the structure for the house may be reduced by 30-50% as compared to traditionally made houses.

Description

The present invention relates to a method for building a structure for a house wherein at least the outer walls of the house are constituted by prefabricated wall elements which are raised on a foundation and fixed to each other, whereupon the house is provided with a roof, and openings for doors and windows are cut out of the wail elements for later installation of the doors and windows.
The foundation for such houses is commonly a concrete ring wall, which will have to be protected against frost and must have a perfectly horizontal top surface. Such ring walls are therefore quite expensive. Prefabricated walls are previously known as sandwich structures having a foam plastic core with gypsum plates on either side thereof. The parts of the walls which are cut out for doors and windows will normally have no sensible reuse and must therefore be discarded. Furthermore, the external sides of the wall elements require a relatively substantial facing in order to withstand wind and weather.
The present invention aims at simplifying the method for such houses and at the same time making the house less expensive and providing it with very good thermal insulating properties.
This is obtained by a method according to the type mentioned by way of introduction, where the characteristic features are that the foundation is cast from a lightweight concrete such that the foundation covers the entire base of the house and furthermore extends a given distance outside the outer walls of the house, the foundation being cast up to a predetermined distance below the level of the finished floor, that accurate grooves for the wall elements are formed in the foundation, said grooves having a width adapted to the thickness of the respective wall elements and having a bottom lying at a level at a predetermined distance below the level of the finished floor, that the wall elements, which also are cast from lightweight concrete, are placed into their respective grooves and are connected to each other and the foundation, preferably by gluing, that pipes and conduits for sanitary and electrical installations are mounted on the foundation, and that a sub-floor in lightweight concrete is cast on the foundation up to a predetermined, lower distance below the finished floor.
Since the grooves for the wall elements can be made accurately, both regarding their positioning and exact bottom level, the wall elements will assume their exact position when they are placed into the grooves. Thus, a concrete ring wall with an accurately leveled crown becomes unnecessary. The work involved in raising the walls can proceed very quickly, and the connections between the walls and the foundation become completely sealed. The glue used in the connections may be a cement paste.
The foundation, the wall elements and the sub-floor may all be cast in the same or similar lightweight concrete, preferably of the type of lightweight concrete being commercially available under the trade name polyconcrete and comprises EPS spheres, cement, additives which provide adhesion between the EPS spheres and the cement, and the water. The walls may preferably have a thickness of about 25 cm, while the sub-floor is somewhat thicker, preferably about 45 cm. This means that the parts of the wall elements which are cut out to provide room for doors and windows may be placed on the foundation and cast into the sub-floor. This will save pouring material for the sub-floor and concurrently permit the reuse of the parts cut out. The polyconcrete is in itself a good example of reuse. This is due to the fact that the EPS spheres the polyconcrete contains come from EPS material previously used in packaging material, such as fish cases and pressure-protecting packaging material used for a number of commercial products.
Also the roof of the house may be made from lightweight concrete elements. These may have a thickness of 30-40 cm, depending upon their length, and they are provided with tensile reinforcement. One has also tried to include compressive reinforcement in the roof element, but this has turned out to reduce the deflection, possibly due to a higher shear deformation in the element. In other respects, the roof elements have proven to be very stable when subjected to temperature differences.
Since the wall elements have a relatively large thickness, it has been feasible to mill grooves in some of the corners of the house for downpipes from the roof, thereby both protecting the downpipes and being architecturally advantageous. Furthermore, the lightweight concrete used has high drainage ability, thus making a single layer of plaster sufficient external surface treatment of the wall elements. The internal treatment may also be a single layer of plaster.
External decorative elements, such as prefabricated facade columns or cornice elements for the roof may also quite simply be glued in place and be varied in a number of ways in order to provide the house with a special character.
The internal sub-floor may be finished with tiles or colour-printed levelling mass, which may be used directly on the lightweight concrete. Any pipe coils for water-based heating or heating cables are cast into the sub-floor before the flooring is completed.
A house built in accordance with the present invention will have very good thermal insulating properties. As an example, one has found that in a structure having a floor area of 90 m²it was possible to maintain an inside temperature of 25° C. at an outer temperature of −4° C. by means of a single heater of 1500 W. Furthermore, for use in cold areas, the requirement to frost protection of the house will be satisfied if the foundation extends about 1 m outside the outer walls of the house.

For a better understanding of the invention, it will be described more closely in connection with the exemplifying embodiment shown in the appended schematic drawings, where:

FIG. 1 shows a perspective view of a foundation for a house according to the invention,

FIG. 2 shows a perspective view of the foundation in FIG. 1 with wall elements installed,

FIG. 3 shows a cross section at a larger scale of a lower portion of a wall and the foundation, and

FIG. 4 shows the subject of FIG. 2 with the roof installed.

FIG. 1 shows a base plate or foundation 1 for a house according to the invention. The foundation, which consists of lightweight concrete, preferably so-called polyconcrete, has been cast directly on the ground following its drainage and levelling. The thickness of the foundation may be about 20 cm, but the surface will usually not be completely flat, nor will it be exactly horizontal. In order to simplify the erection of the walls of the house, the walls being prefabricated in the form of wall elements which are also cast from polyconcrete, and concurrently ascertain that they will be standing on a base which has the correct height and is completely horizontal, accurate grooves are milled in the foundation in the exact position of the walls. These grooves are milled by means of a milling machine, which is guided along a beam, which by means of laser equipment is aligned such that the groove will be located exactly where it is supposed to be and has a bottom which is exactly horizontal and lying at the correct level. The depth of the grooves, which are somewhat exaggerated in FIG. 1, will have a varying depth according to inaccuracy of the surface of the foundation 1 and may vary e.g. between 1 and 3 cm, but may also in places be substantially deeper.
It will be noted that the foundation 1 extends outside the grooves 2 for the wall elements at a distance a, which preferably is about 1 m in order to protect the foundation from the influence of frost in the area of the wall elements.
FIG. 2 shows the foundation 1 after all the wall elements having been put in place and glued to each other and to the foundation 1 in the grooves 2 by means of cement-based glue. Also, the wall openings 3 and window openings 4 have been cut out in the elements, this being done only after the walls having been placed on the foundation. The house consists initially of four different elements, 5, 6, 7 and 8 having different sizes. However, it will be understood that the house may be made so that the number of different wall elements becomes less if this should be of particular importance. In any case, the wall elements are inexpensive to manufacture, and a larger number of different wall elements will not have any great effect on the cost of the house.
With the house in the condition shown in FIG. 2, the pipes and conduits for sanitary and electric installations (not shown) are mounted on the foundation, and the parts of the walls which are cut out to form door openings 3 and window openings 4 are placed between the pipes on the foundation. Thereupon a sub-floor is poured on top thereof to a predetermined height, for instance 5 cm below the finished floor, which may have a level about as shown by the line 9 on the wall elements 6. The sub-floor may thus have a thickness of about 30 cm. The flooring or any elements for floor heating (not shown) are placed on top of the sub-floor.
FIG. 3 shows a sectioned portion of the lower part of a wall element 5-8 and the surrounding part of the foundation 1 with the groove 2 to illustrate the relative dimensions of their magnitude. The wall element shown may have a thickness of 25 cm.
FIG. 4 shows the building in FIG. 2 after being provided with a roof 10, 11, which also is made from wall elements cast from polyconcrete, as noted above. The orientation of the elements are not shown in FIG. 4, but they will extend in the longitudinal direction of the walls 5 and 7. It will be noted that the elements on the roofs 11 have a somewhat smaller thickness than on the roof 10, which is due to the length of the elements. As mentioned previously, the shorter elements may have a thickness of 30 cm, while the longer elements have a thickness of 40 cm. Furthermore, the roof 10 is raised somewhat with respect to the roofs 11 for architectural reasons.
The invention is not limited to the exemplifying embodiment described above, but may be varied and modified by the skilled person within the scope of the following patent claims.

Claims

1-10. (canceled)

11. A method for making a structure for a house wherein at least the external walls of the house are made from prefabricated wall elements which are raised on a foundation and are attached to each other, whereupon the house is provided with a roof, and openings for doors and windows are cut out of the wall elements for installation of the doors and windows, wherein the foundation is cast from a lightweight concrete such that the foundation covers the entire base of the house and furthermore extends a given distance outside the outer walls of the house, the foundation being cast up to a predetermined distance below the level of the finished floor, wherein accurate grooves for the wall elements are formed in the foundation, said grooves having a width adapted to the thickness of the respective wall elements and having a bottom lying at a level at a predetermined distance below the level of the finished floor, wherein the wall elements, which also are cast from lightweight concrete, are placed into their respective grooves and are connected to each other and the foundation, wherein pipes and conduits for sanitary and electrical installations are mounted on the foundation, and wherein a sub-floor in lightweight concrete is cast on the foundation up to a predetermined, lower distance below the finished floor.

12. A method according to claim 11, wherein the wall elements and the sub-floor are cast of the same or similar type of lightweight concrete as the foundation.

13. A method according to claim 11, wherein the lightweight concrete used comprises EPS spheres, cement, additives which provide adhesion between the EPS spheres and the cement, and water.

14. A method according to claim 11, wherein the parts of the wall elements which are cut out for doors and windows are cast into the sub-floor.

15. A method according to claim 11, wherein the foundation extends a distance in the order of magnitude 1 m outside the external walls of the house.

16. A method according to claim 11, wherein said predetermined distance to which the foundation is cast below the level of the finished floor, is about 45 cm.

17. A method according to claim 11, wherein the order of magnitude of the thickness of the wall elements is 25 cm.

18. A method according to claim 11, wherein slots for downpipes from the roof are milled into some of the corners of the house.

19. A method according to claim 11, wherein the wall elements are provided at least externally with a layer of plaster.

20. A method according to claim 11, wherein the roof of the house comprises elements which are made from a similar or the same lightweight concrete as the wall elements and are provided with tensile reinforcement.

21. A house made by the method according to claim 11.

22. A method according to claim 12, wherein the lightweight concrete used comprises EPS spheres, cement, additives which provide adhesion between the EPS spheres and the cement, and water.

23. A method according to claim 12, wherein the parts of the wall elements which are cut out for doors and windows are cast into the sub-floor.

24. A method according to claim 12, wherein the foundation extends a distance in the order of magnitude 1 m outside the external walls of the house.

25. A method according to claim 12, wherein said predetermined distance to which the foundation is cast below the level of the finished floor, is about 45 cm.

26. A method according to claim 12, wherein the order of magnitude of the thickness of the wall elements is 25 cm.

27. A method according to claim 12, wherein slots for downpipes from the roof are milled into some of the corners of the house.

28. A method according to claim 12, wherein the wall elements are provided at least externally with a layer of plaster.

29. A method according to claim 12, wherein the roof of the house comprises elements which are made from a similar or the same lightweight concrete as the wall elements and are provided with tensile reinforcement.

30. A house made by the method according to claim 12.