The present invention relates to a system for fixing to the ground walls of buildings with so-called raft foundations, in particular light buildings, such as, for example, buildings with wooden walls, or another material with a low specific weight.

The present invention is nevertheless also applicable to buildings with masonry walls.

The light buildings, in particular with wooden walls, generally comprise a foundation, a so- called raft foundation, made with a cast of reinforced concrete substantially having the shape of a plate, on which supporting elements are fixed, which are also known as ground beams, i.e. elements with a longitudinal extent that form a base to which the walls of the building are fixed.

The ground beams can be made of wood, but, in this case, have the drawback that, being in direct contact with the raft foundation, they are exposed to humidity and rainwater, in addition to possible infiltrations of water coming from inside the building, as can occur, for example, in the case of floods inside the building.

Wooden ground beams exposed to humidity or water can rot and transmit humidity or water infiltrations to the walls of the building causing the walls to deteriorate and the stability of the building to be compromised.

Recently, ground beams have been used that are made of concrete or metal that insulate the walls of the building from the raft foundation, protecting the walls from the infiltrations of humidity and/or water and protecting the walls from deterioration.

Making ground beams of cast concrete does, however, have significant difficulties of manufacture and dimensional tolerances that are such as to make the assembly of the structure of the building above difficult, in particular the walls.

The metal beams enable the walls to be assembled easily and precisely, but are significantly expensive and can significantly affect the cost of the building.

The object of the present invention is to provide a system for fixing to the ground walls of buildings, in particular walls of light buildings, that does not have the aforesaid drawbacks. Another object of the present invention is to provide a system for fixing to the ground walls of buildings, in particular light buildings, which permits precision assembly of the ground beams and of the walls, also in the presence of irregularities in the surface of the raft foundation. A further object of the present invention is to provide a system for fixing to the ground walls of buildings, in particular light buildings, that effectively insulates the walls from humidity and/or water infiltrations.

The aforesaid objects are achieved with a system for fixing to the ground walls of buildings according to claim 1.

Owing to the invention, it is possible to fix with precision the ground beams to the raft foundation of the building in a perfectly horizontal position. It is further possible to fix the ground beams such that they are all at the same level.

Owing to the invention, the walls of the building can be assembled in such a manner that there are no misalignments, either horizontally, or vertically between adjacent walls.

Lastly, owing to the invention, the walls of the building are insulated from the raft foundation and are not subject to infiltrations of water or humidity coming from said foundation.

Further features and advantages of the invention will become clearer from the following description, which is provided merely by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 is a top view of a support element, or ground beam, of the fixing system according to the invention;

Figure 2 is an elevation view of the ground beam of Figure 1 ;

Figure 3 is a longitudinal section of the ground beam of Figure 1 , along the line III-III in Figure 1 ;

Figure 4 is a cross section of the ground beam of Figure 1 , along the line IV- IV in Figure i ;

Figure 5 is a frontal view of the ground beam of Figure 1;

Figure 6 is a perspective view of a fixing element by means of which adjacent ground beams are fixed together;

Figure 7 is a raised view of the fixing element of Figure 6;

Figure 8 is a side view of the fixing element of Figure 6;

Figure 9 is a top view of the fixing element of Figure 6;

Figures 10 and 11 illustrate the manner in which two adjacent ground beams are fixed together;

Figures 12 to 16 illustrate successive steps of fixing to the raft foundation a ground beam of the fixing system according to the invention; Figure 17 illustrates the assembly of a wall on a respective ground beam;

Figure 18 illustrates achieving the thermal and acoustic insulation of a building that is achievable with the system according to the invention, after the assembly of the walls on the ground beams.

In Figures 1 to 5 a support element 1 is illustrated, which is called herein after as a ground beam, made of plastics, for example moulded or extruded polystyrene, and intended to be fixed to the reinforced concrete raft foundation 2 of a building and to constitute a base onto which a wall 28 (Figure 17) of a building (which is not illustrated) is fixed.

The ground beam 1 is part of the system according to the invention for fixing to the ground the walls 28 of the building.

The ground beam 1 made of moulded or extruded plastics is very light and thus easily transportable and manipulatable during implementation. Further, the ground beam 1 has a small cost that contributes to reduce the total cost of a building in which ground beams 1 are used to support the walls 28 of the building.

The ground beam 1 has a prevalent extent in a direction parallel to a longitudinal axis B and comprises a pair of sides 3, provided with reinforcing longitudinal inserts 7, for example made of wood. The sides 3 are interconnected by a plurality of crosspieces 4, in which through ventilation holes 20 can be made (Figure 13), the function of which will be explained in greater detail below. The sides 3 extend perpendicularly to the raft foundation 2 when the ground beam 1 is fixed to the raft foundation 2 whereas preferably the crosspieces 4 are perpendicular to the sides 3.

A plurality of spacers 5 is provided, for maintaining constant the space between the sides 3 along the entire length of the ground beam 1.

On a bottom of the ground beam 1, between the sides 3 and the crosspieces 4, openings 6 are defined, the function of which will be explained below.

A lower part 8 of each side 3 has a length, in a direction parallel to the longitudinal axis B, lower than the length of the side 3 in the same direction, such that a step 9 is defined, between said lower part 8 and the rest of the side 3, at opposite ends of the sides 3 that are perpendicular to said longitudinal axis B.

In Figures 6 to 9, a connecting element 10 is illustrated that is used to connect together two adjacent ground beams 1.

The connecting element 10 comprises an elongated body 1 1, consisting, for example, of a metal section bar, for example C-shaped, it being nevertheless possible to use other forms of section bars, for example a box section bar. The body 11 has a height that is substantially the same as a height of the step 9 and a length the same as a width of the ground beam 1 in a direction perpendicular to the longitudinal axis B.

At opposite ends of the body 11 respective uprights 12 are provided, that comprise a first part 21a and a second part 21b arranged in a T shape and are arranged for being fixed to the sides 3 of two adjacent ground beams 1 to be connected. The uprights 12 extend perpendicularly to the body 11. In the second part 21b of each upright 12, at opposite end zones of said second part 21b, a respective group of holes 13 is provided into which fixing elements 22 can be inserted by means of which the connecting element 10 can be fixed to the ground beams 1 to be connected. Each upright 12 thus has a first group of holes 13 at a first end zone of the second part 21b and a second group of holes 13 at a second end zone opposite said first end zone. The fixing elements 22 can consist of nails, or screws.

Each second part 21b is provided with an abutting element 14, for example in the form of a tab, that is used to position the connecting element 11 correctly with respect to the ground beams 1 to be connected, as will be explained in greater detail below. The abutting element 14 can be obtained by punching.

The body 11 is provided with a pair of further holes 15, arranged in a symmetrical position with respect to a vertical central axis A of the body 11 , and with yet a further hole 16 arranged at the central axis A. The term "vertical" means an axis that is parallel to the direction of the force of gravity.

The further holes 15 are intended for housing respective adjusting elements 17 that are used for adjusting a distance of the body 11 from the surface of the raft foundation 2 and correcting possible tilts of the body 11, so as to position the body 11 exactly horizontal. The adjusting elements 17 can consist of adjusting screws, in which case the further holes 15 are threaded.

The still further hole 16 is intended for housing an anchoring element 18, which is used to fix the connecting element 10 to the raft foundation 2 of the building.

The anchoring element 18 can consist of a self-tapping screw for concrete.

In Figures 10 and 11 it is illustrated how two adjacent ground beams 1, 1A are connected together using the connecting elements 10.

In Figure 10 a first step is illustrated of the connecting procedure in which a connecting element 10 is placed at an end of a first ground beam 1, such that the body 11 is inserted into the step 9, until the abutting elements 14 abut on the ground beam 1, at the reinforcing elements 7, such that a first group of holes 13 of each upright 12 is situated at a respective reinforcing element 7 of the first ground beam 1. Subsequently, a second ground beam 1A is brought up to the first ground beam 1 until an end of the beam 1A abuts on the end of the ground beam 1 on which the connecting element 0 rests, so that a second group of holes 13 of each upright 12 is situated at a respective reinforcing element 7 of the second ground beam 1A. Lastly, the connecting element 10 is fixed to the ground beams 1 and 1A by the fixing elements 22 that are inserted into the reinforcing element 7 of the first ground beam 1 through the first group of holes and in the reinforcing element 7 of the second ground beam 1A through the second group of holes 13.

Owing to the connecting element 10, it is possible to fix rapidly together and with precision two adjacent ground beams 1, and, as will be explained in greater detail below, adjust the distance thereof from the surface of the foundation 2 and correct possible tilts with respect to a horizontal reference plane, so as to arrange the ground beams 1 all parallel to said horizontal reference plane, so that there are no misalignments, either horizontally or vertically between adjacent ground beams 1, and thus between the walls 28 supported by the ground beams 1.

In Figures 12 to 18 the steps of making a wall of a building with the system according to the invention are illustrated.

In a first step, Figure 12, at least two ground beams 1, previously fixed together as disclosed above, are placed on the foundation 2 of the building, made previously, arranging the ground beams 1 on the basis of references placed on the foundation 2, for example squaring wires, making a first partial fixing of the ground beams 1 by inserting a self- tapping screw 18 for concrete in the still further hole 16 of the connecting element 10, screwing the self-tapping screw 18 partially in the concrete of the foundation 2.

In a second step, Figure 13, using the adjusting screws 17 a distance of the ground beams 1 with respect to the foundation 2 is adjusted and a tilt thereof, if any, with respect to a horizontal reference plane is corrected using a level. The expression "horizontal plane" means a plane that is perpendicular to the direction of the force of gravity.

In a third step, Figure 14, the two ground beams 1 are fixed definitively to the foundation 2 by fully screwing the self-tapping screw 18 into the concrete. Possible spaces that remain between the sides 3 and the foundation 2 are filled with a filling material 19, for example polymer foam. In a fourth step, Figure 15, possible screw connector elements 23 for concrete are fixed to the foundation 2, the screw connector elements 23 being inserted through the openings 6 in the bottom of the ground beams 1 , and reinforcing metal bars 24 for concrete are arranged inside the sides 3, for example being arranged resting on the crosspieces 4.

In a fifth step, Figure 16, a cast of concrete 25 inside the sides 3 of the ground beams 1 is made, for example a cast of concrete reinforced with fibres. The cast of concrete 25 completely fills the space existing between the sides 3, above and below the crosspieces 4, passing through the openings 6 and coming into contact with the concrete of the foundation 2. Further, the cast of concrete 25 envelops the screw connectors 23 and the reinforcing metal bars 24.

The screw connectors 23, previously fixed to the foundation 2, are used to secure the cast of concrete 25 to the foundation 2, whereas the reinforcing metal bars 24 are used to increase the structural resistance of the cast of concrete 24.

The upper surface 26 of the cast of concrete 25 is smoothed so that it is parallel to said horizontal reference plane and does not protrude above the sides 3.

Lastly, a possible transparent sheath 27 is placed on the ground beams 1.

In a sixth step, Figure 17, on the upper surface 26 of the cast 25 of concrete a prefabricated wall 28 is fixed, which is made of material with a low specific weight, for example with wooden panels, fibre plaster or fibre cement panels, or panels consisting of a metal frame filled with thermal and/or acoustic insulating material.

The wall 28 is fixed to the upper surface 26 of the cast of concrete 25 by a plurality of fixing means 29, 30, 31, that comprise, for example, a plurality of L-shaped brackets 29, which are fixed to the wall 28 by further fixing elements 30, consisting, for example, of nails or screws, and to the cast of concrete 25 by still further fixing elements 31, for example concrete screws or expansion plugs.

Alternatively, if the wall 28 is a masonry wall, the wall 28 is made directly on the cast of concrete 25, the masonry wall 28 being fixed to the cast of concrete by mortar.

In a sixth step, Figure 18, an outer surface of the wall 28 is coated with first thermal and/or acoustic insulating means 32, consisting, for example, of panels of thermal insulating material or both thermal and acoustic insulating material, and on the inner surface of the wall 28 second thermal/or acoustic insulating means 33 is placed, which also consists, for example, of panels of thermal insulating material or of thermal and acoustic insulating material. Subsequently, after the walls 28 of the building have been finished, the subfloors 34 of the building are made, to which will be fixed the floors of the building, and a ventilation space 35 is made, for example an igloo ventilation space, that insulates the blocks 34, and thus the floors of the building, from possible infiltrations of humidity coming from the ground on which the building stands.

The ventilation of the ventilation space 35 is ensured by the ventilation holes 20, made in the crosspieces 4 of the ground beams 1, that communicate at one end with the environment outside the building, and at another end with the ventilation space 35.