WO2003057997A1

WO2003057997A1 - A foundation structure

Info

Publication number: WO2003057997A1
Application number: PCT/SE2002/002318
Authority: WO
Inventors: Åke MÅRD
Original assignee: Maard Aake
Priority date: 2001-12-17
Filing date: 2002-12-13
Publication date: 2003-07-17
Also published as: SE0200679L; CA2467942A1; CN100476083C; DE60234126D1; SE0200679D0; CN1604982A; AU2002359129A1; JP2005514543A; RU2004120068A; EP1466055B1; ATE446416T1; US20050011149A1; EP1466055A1; RU2334050C2; ES2335483T3

Abstract

A building foundation structure comprising a supporting and heat and moisture insulating layer (17, 18, 40), preferably of foam glass, which rests on a flat and horizontal surface (51) of a ground layer (50), and metallic foil (111) that covers the horizontal area of the foundation structure, in order to prevent moisture and smell,.for example jusmin odour, to propagate upwardly through the supporting and heat and moisture insulating layer (17, 18, 40).

Description

A FOUNDATION STRUCTURE

The present invention relates to a building foundation structure of the kind defined in the preamble of claim 1.

More particularly, the invention relates to a ground-supported foundation structure. Normally, the ground is drained and a capillarity breaking layer of material , e.g. crushed stone, is strewn over a flat and horizontal upper surface of the ground, said material having a particle size of 2— 4mm.

It is well known, not least from the experience gained over a long period of foundation work, that ground-supported foundations run the risk of allowing moisture to migrate through the foundation structure and into the building erected on the foundations. Smells are also liable to penetrate through the foundations. It has been found in particular that the ground's own smell, "jusmin" odour , is liable to percolate through known foundation structures.

In addition to being impervious to smells/odours, it is necessary that a foundation structure can be established quickly and at low cost, and that the imperviousness of the structure will satisfy the requirements of being well integrated with the foundation structure.

Accordingly, an object of the present invention is to provide a generally smell/odour- impervious foundation structure that can be readily constructed in desired sizes from lightweight elements.

Foil that is impervious to jusmin odours and that retains its integrity for a very long time in the environment in which it is placed, for example a time period in the order of one hundred to several hundred years, is placed on a supporting surface, suitably a levelled layer, over the ground area. The foil is often exposed to ground moisture and moisture of condensation in an environment which will relatively often be acid or contain aggressive substances. Consequently, it is particularly suitable to choose a metallic foil material that can withstand such an environment over a long period of time while still retaining its imperviousness to jusmin odours.

When the metallic foil, for instance Al-foil, shall be laid essentially directly on the ground levelling layer, so that it will lie in direct contact with the granular material in said layer, the foil will preferably have a relatively large thickness, e.g. a thickness in the order of 0.1 - 1mm, so as to ensure that the foil will not be penetrated when subjected, in time, to the load exerted by a building construction, via the foundation elements, and brought into intimate contact with the levelling layer. At such thicknesses, the metallic foil can be obtained/delivered in roll form and unwound from the roll at the site of the foundation structure and laid over the foundation area. The foil will also have a good tear strength, therewith minimising the risk of damaging the foil as it is laid out. If, for practical reasons, the width of the foil is smaller than the width of the foundation structure, foil lengths can be lain adjacent one another with a join therebetween, e.g. an overlap join, so as to ensure the imperviousness of the foil layout to smells/odours. The overlap foil may have a width which is adapted in this respect and may include a strip or layer of glue, adhesive tape or some readily deformable foil, preferably springy foil, that has substantial width in the breadth direction of the overlap foil and therewith ensure that impermeability to smells and odours is achieved over a wide area in the air leakage direction. A single overlap joint between mutually adjacent strips of Al-foil will normally suffice, since such joints are usually pressurised along the whole of their length. The levelling surface may, of course, be covered with plastic foil prior to laying out the metallic foil, for instance in order to prevent the ingress of sand/grains into a possible overlap joint between adjacent strips of Al-foil. In one embodiment of the invention, the Al-foil may be laminated with plastic foil if so desired, for instance from a handling aspect, although the relatively thick and odour- proof foil, preferably aluminium foil, used in accordance with the invention is able to retain its integrity for a very long time in its environment, which is often aggressive. The majority of plastic foils would lose their integrity in said environment over the same period of time.

In another embodiment of the invention, the odour-proof foil, e.g. Al-foil, may, of course, be placed between two layers of heat insulating material included in the foundation structure, in which case the Al-foil may be thinner, because the insulating material defines a smooth and even support surface onto which the foil can be rolled out. The object of the invention is achieved. The invention is defined in the accompanying independent Claim while further embodiments of the invention are defined in the dependent Claims.

In the case of a particularly preferred embodiment of the invention the surface of the ground is first prepared by draining the ground and then laying on the surface a layer of capillarity breaking material, for instance crushed stone, having a particle size of 2-4mm, and thereafter smoothing the layer to obtain a flat and horizontal surface.

Prefabricated standard size sheets or sheets, e.g. rectangular sheets, of cellular insulating material, such as foamglas^R' having a thickness of 50mm for instance are laid tightly against each other in a first layer on the crushed stone. A further layer of such sheets may optionally be lain in mutual tight abutment on the first layer, wherewith the joins between adjacent sheets of the second layer will be offset in relation to the joins in the first layer.

It is endeavoured to achieve a liquid tight join when joining the sheets together. The cellular insulating material is preferably foamglas^R or some other material that provides an absolute minimum of water adsorption or absorption and that is also highly pressure resistant and safe against vermin and that is effectively heat insulating and diffusion tight.

The insulating layers are conveniently surrounded by a frame, whose members may consist of sheet metal U-beams, wherein the concave side of respective beams faces towards the interior of the foundation element. The area within the frame is filled with pressure-strong heat insulating material, for instance two superposed layers of cellular insulation (2 x 100mm foamglas) The frame of the foundation element can be stabilised, by mounting sheet-metal I-beams in said frame parallel with one of the frame U-beams. The sheet-metal beams of the foundation element are joined mechanically in a manner to stabilise the element. The foundation element may have a thickness of 200mm for example. The use of U-beams and I-beams in respect of the foundation element means that the cellular insulating sheets can be shape-bonded to the beams by inserting those sheet portions adjacent the beams into the concave part thereof. Moreover, the upper horizontal flanges of the beams will provide anchorage points for the wall construction of a building erected on the foundation structure. The building structure may be of the kind that has the form of a prefabricated box, which is usually produced in a factory situated at some distance from the foundation structure. Alternatively, the foundation element may be placed separately on the foundation structure and the components of a loose timber structure or a frame house then mounted on the foundation element and anchored to its sheet-metal flanges.

Because we have found that even in the case of sealing foil, e.g. plastic foil, that has a low smell transmission capacity, the foil will still allow smells and odours to wander therethrough in practice, we prefer to use a sealing layer that is comprised of a metal alloy or a metal.

So far as we are aware, aluminium foil provides the desired imperviousness to odours, even at thicknesses as small as 0.01mm - although thicker foils will, of course, provide greater security in this respect and will also facilitate construction of the foundation structure, since foils of the type in question can be delivered in rolls from which foil strips can be unwound and flattened and then laid on the foundation structure.

The invention will now be described by way of example with reference to the accompanying drawings, in which

Figure 1 is a schematic vertical sectional view of an inventive foundation structure;

Figure 2 is a schematic illustration of an overlap join between two strips of foil consisting of odour-impervious material;

Figure 3 illustrates a variant of the subject of Figure 1;

Figure 4 shows another embodiment of the subject of Figure 1;

Figures 5, 6, and 7 are respective views of frame elements in a frame construction that can be included in the foundation structure; and

Figure 8 illustrates an embodiment of a sheet to which sealing foil has been pre- fitted.

Referring to Fig. 1, it will be seen that at the site of the foundation structure there is a drained ground layer 50 which may consist of or be covered with a capillarity barrier, preferably a layer of crushed or broken stone, wherein the upper surface 51 of the barrier 50 is essentially flat and horizontal.

Placed on the surface 51 is aluminium foil or metal sheeting 1 1 1 which has a preferred thickness of at least 0.1 mm, and more preferably a thickness of 0.3 - 0.5mm. Established on the foil 1 1 1 is a layer of heat insulating material, preferably foamglas. Sheets of foamglas 40 are joined together and placed over the foil 1 1 1. The sheets 40 are stabilised with the aid of a frame 31 which surrounds at least the mutually joined sheets 40.

When the foil 1 1 1 is obtained in the foπn of strips whose width is smaller than the width of the foundation structure, the foil strips may be placed with an overlap join 1 12. A sealing layer, e.g. a time-durable adhesive, may be applied across the width of the join to minimise the danger of smells being transmitted vertically through the mutually joined foils 111. Alternatively, a sealed join can be established with the aid of welds, adhesive tape or there technical correspondence.

Figure 3 illustrates an embodiment in which a layer 17 of heat insulating material, e.g. mutually joined sheets 10 of foamglas, is placed on the surface 51 of the capillarity barrier, wherewith Al-foil is placed on the layer 17, prior to placing the foundation layer, established by the sheets 40 and the frame 31 , on the foil 111.

Figure 4 illustrates a variant in which a further layer 18 of sheets 10, mutually joined at their respective edges, is placed on the foil 111 before the frame with sheets 40 is placed on the layer 18.

The frame 31 surrounds the foundation layer established by the sheets 40 so as hold the foundation structure together in the horizontal plane, said frame also providing anchorage points for the building to be supported by the foundation structure. According to one embodiment of the invention, the exposed parts of the edges of sheets 40 may be recessed to receive the legs of a generally U-shaped frame member 32 (Fig. 5). In the embodiment according to Fig. 6, the frame member 32 has roughly the same height as the sheets 40 although the top and bottom surfaces of said sheets are slightly recessed to enable them to receive the legs of the frame members 32. Figure 6 shows that I-beams 37 may be arranged in the joins between adjacent sheets 40, said sheets having in the join regions recesses that receive the flanges of the I-beams so that the I-beams can also have the same height as the sheets 40. However, it is preferred at present that the free distance of the frame members between said flanges corresponds to the thickness of the sheets of insulating material. The flanges on the frame members have only a small thickness, e.g. a thickness of 1mm, and their position above the main surfaces of the sheets normally causes no trouble.

The frame 31 is normally rectangular in shape and comprises straight, U-shaped sheet metal profiles which are joined together (FIG. 7) at the corner regions of the frame by means of rivets, screw joints, glue joints or corresponding fastener means between overlapping leg portions of sheet metal profiles, which have essentially the same web measurement and a small material thickness, e.g. a thickness of 1 mm.

It will be seen from Fig. 6 that pull rods 43 may be extended between the members of the frame 31 so as to hold the frame members together in the horizontal plane.

It will be understood that the frame 31 with associated heat insulating sheets 40 can foπn an integral part of a prefabricated box unit, so that the foundation structure can be completed by placing such a prefabricated box unit onto the foundation structure and supplementing any parts of the foundation that may have been earlier mounted on the site of the foundation structure, wherewith prefabricated box units may be joined together to form the body of a building on the foundation structure.

Naturally, the foundation structure can be established in the manner shown in Figs. 1, 3 and 4, wherein the framework of a building can be erected in accordance with loose timber techniques or block ? techniques and anchored to the frame structure.

By way of a modification of the embodiment shown in Figs. 3 and 4, there may be included an additional frame which grips all other heat insulating layers and possible inteπnediate or outwardly lying foils/metal sheets 111.

One of the heat insulation layers (17, 18) may be formed by preferably rectangular heat insulating elements 10 that are mutually joined along their edges. One main surface of respective elements 10 may be covered with a piece of metal foil 11, preferably aluminium foil. The pieces of metal foil 11 on the elements 10 can be sealingly connected with overlap joints, e.g. by overlapping strips 12 of said metal foil on the foil side ot mutually adjacent elements along their respective joins. Alternatively, the foil covering on respective elements 10 may have an edge portion 12 that projects out beyond the edges of two mutually adjacent edges and overlaps the foil covering at the edges of said adjacent elements.

Both of the layers 17, 18 may be built up by joining together such prefabricated sheets 10 provided with a foil covering 11. The sheets 10 of said two layers may conveniently be orientated so that their foil cladding 1 1 will be in mutual contact, whereby the insulating sheets 10 of the layers 17, 18 will be separated by two mutually bordering layers of foil material. The foil cladding or covering 1 1 on the sheets 10 has an equivalent composition to that of the aforedescribed foil 111.

Preferably, the joins between the sheets 10 in respective layers 17, 18 will be offset in relation to one another.

Claims

1. A building foundation structure comprising a heat and moisture insulating layer (17, 18, 40) which rests on a flat and horizontal surface (51 ), characterised in that the area of the foundation structure is covered with a foil

(1 1 1 ) of metallic material.

2. A foundation structure according to Claim 1 , characterised in that the foil (1 1 1 ) is located beneath the layer (17, 18, 40).

3. A foundation structure according to Claim 1 or 2, characterised in that the foil

(I I) rests directly on said surface (51); and in that said surface is comprised of a capillarity barrier layer, preferably consisting of crushed or broken stone.

4. A foundation structure according to any one of Claims 1 - 3, characterised in that the foil is an Al-foil with a thickness of at least about 0.1mm, preferably a thickness of less than 1mm, such as more preferably a thickness of roughly 0.5 mm.

5. A foundation structure according to Claim 1, characterised in that the layer

(17, 18, 40) includes at least two courses (17, 18) of insulating material; and in that the metallic foil (111) is sandwiched between two vertically adjacent insulating courses.

6. A foundation structure according to Claim 5, characterised in that the foil

(I I I) has a thickness of at least 0.01mm, preferably a thickness of at most lmm.

7. A foundation structure according to any one of Claims 1 - 6, characterised by a frame (31) that surrounds said layer at least at the upper layer parts.

8. A foundation structure according to any one of Claims 1 - 7, characterised in that parts of the frame (31) together with parts of the heat and moisture insulating layer are integrated in respective prefabricated building box units which when placed on the foundation structure together form a building framework on said structure.

9. A foundation structure according to Claim 5, characterised in that each of the layers (17, 18) is formed by mutually joined sheets (10) of insulating material; in that one main surface of each sheet (10) is covered with a piece of foil (1 1), wherein said foil pieces (1 1) together form the first mentioned foil (1 1 1); in that the layers (17, 18) cany said foil pieces (1 1) on their mutually facing sides; in that a strip (12) of said foil material, preferably aluminium, sealingly joins together the foil coverings or cladding (1 1) on adjacent sheets (10) in at least one of the layers (17, 18); and in that the joins between the sheets (10) in respective layers (17, 18) are offset relative to each other.

10. A foundation structure according to Claim 1, characterised in that the strips (12) are fomied by edge portions (12) of the sheet-covering foil that protrude beyond the edge portions of respective sheets (10) along two adjacent edges thereof, wherewith the outwardly projecting edge portions (12) of said foil coverings are caused to overlap an adjacent edge portion of the foil coverings (1 1) of adjacent sheets.