AU648203B2 - Footing unit - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT r r, r Name of Applicant: Actual Inventor: Address for Service: BESSER PIONEER PTY LTD VANCE JOSEPH SELLEN CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

Invention Title: FOOTING UNIT Details of Associated PL2291.

Provisional Applications: Nos. PK9412 and The following statement is a full description of this invention, including the best method of performing it known to us: THIS INVENTION relates to a footing unit for use with a poured concrete slab.

Concrete slabs and particularly concrete floor slabs for dwellings are usually required to be at least 100 mm thick and are required. to be poured onto a minimum thickness of bedding sand. The edges of the concrete slab are usually required to be of increased thickness to provide strength in this region to support the weight of wall frames. This thickened portion usually also includes reinforcement in the 1 0% form of steel bars or rods which may be tied into bundles.

In practice, to lay a concrete slab, the area is initially excavated and levelled and a trench is dug around the periphery of a depth corresponding to the required ••thickness of the concrete. Bedding sand may then be placed in the excavated portion taking care that the bedding sand does not fall into the trench. To assist this, it is usually necessary to peg barriers around the inside wall of the trench :i to prevent sand and other debris from falling therein. A further difficulty is when concrete slabs are to be laid on loose or gravelly soil or sand as in these instances, the walls *of the trench are usually prone to collapsing. This requires the walls of the trench to be shored up which adds to the cost and time, in laying the slab. Furthermore, as the tranches are usually excavated by a backhoe, to is often the case that the trench is dug deeper or wider than necessary resulting excess use of concrete. Alternatively, once a trench is dug it needs to be lined and back filled to ensure the correct size and depth. Again, this adds to the cost of laying the slab.

After the trench has been dug, reinforcement bars are laid in the trench and are required to be spaced above the floor of the trench by bar chairs or other support means.

Again, this adds to the time and cost of laying the concrete slab. Once a reinforcement (or service ducting) has been positioned in the trench, concrete is poured into the trench .:to provide the necessary footing. Once the concrete has hardened, the floor slab is poured which extends over the concrete poured in the trench usually by a thickness of 100 mm. To ensure the correct thickness of the floor slab, timber lengths of 100 mm height are laid about the periphery of the slab against which the concrete is poured. The concrete can S then be screeded flat and finished in the usual manner.

For brick veneer houses, the outer most row of bricks are supported directly by the concrete in the trench.

Usually, the first few rows of bricks are also used to provide oioo formwork against which the concrete slab can be poured.

Australian patent 583565 discloses a footing element for a wall foundation. The footing element however provides no support to allow a row of bricks to be correctly placed and positioned.

It is an object of the invention to provide a footing unit which may overcome some of the abovementioned disadvantages.

In one form, the invention resides in a footing unit for use with a poured concrete slab, said footing unit comprising a base wall, a pair of spaced side walls extending 4 from the base wall and defining a channel therebetween, and, a shoulder portion extending outwardly from one of the side walls and adapted to support a column of bricks.

The footing unit can be placed in the base of a roughly dug trench and can be placed onto a bed of sand to level the footing unit. A number of such footing units can be placed in a side-by-side relationship, the number depending on the length of the trench. Alternatively, for raised slabs, the or each footing unit can be merely placed on a ground surface.

S.The base wall may be substantially planar in configuration and suitably is of a substantially rectangular shape when viewed in plan. The thickness of the base wall may vary depending on the weight to be supported but usually is of a thickness between 20 mm to 100 mm and preferably of a thickness of about 50 mi.

The side walls may extend from adjacent opposed edges of the base wall. Suitably, the side walls extend substantially at right angles from the base wall so that the side walls are substantially parallel relative to each other.

The thickness of the side walls may vary and a suitable range of thicknesses is between 20 mm to 100 mm with a preferred thickness being approximately 50 mm.

One of the side walls may have a free upper end which is spaced above the free upper end of the other of the side walls. Suitably, the spacing between the free upper ends corresponds to the desired thickness of the slab to be poured.

As the thickness of a slab is usually between 100 mm to 200 mm, it is preferred that the spacing between the side walls is also between 100 mm to 200 mm. Alternatively, the one side wall may have an increased spacing which can be chipped or cut away to the desired height. To assist this, lines of weakness may be introduced into the one side wall. Of course, the other of the side walls could also be chipped away or cut to provide the desired spacing between the two side walls.

The free upper end of the one side wall may include a ramped or bevelled portion to assist in the correct placing IQ of flashing as shall be described in greater detail below,, The shoulder portion may extend outwardly from an outer face of the one side wall. The shoulder portion suitably includes a planar upper face which in use is ••substantially horizontal. The planar upper face may have a cross-sectional size adapted to support the base of a brick or like building member. The thickness of the shoulder portion may vary depending on the weight of bricks or other building :i elements to be supported thereby. A suitable range of thicknesses may be between 50 mm to 200 mm with a preferred thickness being about 100 mm.

The footing unit may include spacing means to space reinforcing, service ducts or the like above the base wall.

Spacing means may comprise a projection. The projections may be in the form of a ramp having an upper knife-like support edge to. provide a relatively fine line contact between the reinforcement, service ducts or the like. This assists in a good flow of concrete around the reinforcement or the like.

The spacing means suitably spaces the reinforcement or the like approximately 30 mm to 100 mm above the base wall.

Spacing means is suitably formed within the channel defined by the side walls and can be formed integrally with the footing unit. Under certain conditions it may be desirable to place the footing unit in a deeper than normal trench, that is a trench dug deeper than the height of the side wall containing the shoulder portion. Therefore, there may be provided an extension piece. The extension piece may be supported adjacent an upper free end of the side wall and can function to extend the height of the side wall should this be Snecessary. If desired, one or both of the side walls may be provided with an extension piece.

S. Suitably, the extension piece has a configuration to S allow it to be self-supporting to an upper end of the side wall and this may be achieved by having a skirt portion .00 overlying a portion of the side wall below the upper end thereof.

In another form, the invention resides in a method for laying a concrete floor comprising using one or more of the footing units described above and subsequently pouring concrete to provide the concrete floor.

The invention will be better described with reference to the following description of a preferred embodiment thereof in which Figure 1 is a view of a footing unit according to an embodiment of the invention Figure 2 is a view of the footing unit in use Figure 3 is a view of an extension piece according 7 to an embodiment of the invention Figure 4 is a view of the extension piece fitted to the footing unit.

Referring to the drawings, there is disclosed a footing unit 10 which may be formed from concrete. Footing unit 10 comprises a base wall 11 and a pair of side walls 12, 13, and a shoulder portion 14, base wall 11 is substantially planar in configuration and is rectangular in shape and is approximately 50 mm in thickness. Side walls 12 and 13 extend 1 from adjacent opposed edges of base wall 11 and extend S upwardly at right angles to define a substantially U-shaped channel 15 between the base wall and the respective side walls. The thickness of each side -wall in the embodiment is ••about 50 mm. One of the side walls 13 has an upper free edge 16 which extends above the upper free edge 17 of the of side walls 12. The spacing between upper edges 16 and 17 corresponds to the thickness of the slab to be poured as more :i clearly shown in Figure 2. The spacing between side walls 12 and 13 may be about 350 mm.

Shoulder portion 14 may extend at right angles from side wall 13 and adjacent a lower portion thereof. As shown In the embodiment, shoulder portion is part of the footing unit and has a lower face 18 which is an extension of the lower face 19 of base wall 11. Shoulder portion 14 is substantially box-like in configuration and includes an upper substantially planar horizontal face 20 to support bricks or like members as more clearly shown in Figure 2. The thickness of shoulder portion 14 may be about 100 mm. The height of the footing unit may be about 300 mm, its length 550 mm and its width about 195 mm.

Footing unit 10 may include spacing means in the form of a projection 21 having a ramped body configuration.

Projection 21 is form part of the footing unit and locates channel 15 and adjacent one edge thereof. The ramped configuration results in a formation of a knife-like support edge 22 which supports reinforcement 23 as shown in Figure 2.

S" The upper free edge of side wall 13 is formed with a IQ ramped or bevelled portion 24 to assist in the correct positioning of flashing 25 as shown in Figure 2.

In use, a line of footing units 10 can be placed in a trench or on a ground surface. Reinforcement 23 (or service ducting, conduit or any other desired material) is then placed within channel 15 and on the knife-like support edge 22.

Concrete can then be poured into channel 15 and over upper edge 17 of side wall 12 to a thickness such that the poured concrete extends to adjacent upper edge of side wall 13. This then ensures the correct thickness of the floor slab to be formed. As the reinforcement 23 is supported by knife-like support edge, concrete can pass around and beneath the reinforcements to further strengthen the foundation of the slab to be formed. A row of bricks 26 can then be laid on shoulder portion 20 as shown in Figure 2 and flashing 25 can be added according to the building regulations with ramped surface 24 assisting in bending the flashing upwards to allow it to be nailed or fastened to wall frame 27. Wall frame 27 can be -placed directly onto formed slab 28 in the manner 9 shown. Referring to Figures 3 and 4 there is shown an extension piece 30 which can function to extend the height of side wall 13. It should be appreciated however that an extension piece can also be fitted or supported to side wall 12 if desired.

Extension piece 30 has a main body 31 and a skirt portion 32. In use (see Figure 4) skirt portion 32 overlies a wall of side wall 13 to provide a degree of stability to extension piece 30 to allow it to be self-supporting. In the S S 1Q embodiment, side wall 13 is provided with a rJmped or bevelled top wall and for this reason extension piece 30 is also provided with a correspondingly configured ramped wall 33 so that the two components can mate together. As the ramped or bevelled top wall of side wall 13 was desired to assist in fastening flashing, the extension piece is also provided with a ramped or bevelled top portion 34 such that flashing can still be conveniently fitted.

.of The advantages of a footing unit according the embodiment of the invention is that it enables the footing and slab to be poured in the one pour. Services such as plumbing can be installed according to the latest building regulat'.ons.

The footing unit can be used with brick veneer, timber and other cladding systems. The use of the footing units can save time involved in preparing and aligning formwork. It also saves waste concrete usually involved with footings poured into dug trenches as the tranches are usually much wider at the top than necessary due to the looseness of the soil. The knife-like support edge ensures that reinforcement is properly covered by concrete. The footing units also minimise disruption of the pour in wet wether due to mud and rain in the dug trench.

It should be realised that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention as defined in the appended claims.

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Claims (8)

1. 2. The footing unit as claimed in claim i, wherein the one side wall has an upper edge spaced above an upper edge of the other side wall.
2. 3. The footing unit as claimed in any one of the preceding claims, wherein the spacing between the upper edges of the one side wall and the other side wall conforms to the thickness of a concrete slab poured over the footing unit.
3. 4. The footing unit as claimed in any one of the preceding claims, wherein the one side wall or the other side wall includes lines of weakness to allow the wall to be chipped away or cut to a suitable height.
4. 5. The footing unit as claimed in any one of the *ooo preceding claims, wherein the upper edge of the one side wall slopes downwards from the inner edge to the outer edge.
5. 6. The footing unit as claimed in any one of the preceling claims, wherein the shoulder portion has a cross- ro• sectional size of a brick or block to be supported by the er o o. shoulder portion.
6. 7. The footing unit as claimed in any one of the preceding claims, wherein the unit includes spacing means to space members such as reinforcement and service ducting above the base wall.
7. 8. The footing unit as claimed in claim 7 wherein the specing means comprises a projection or projections extending from the base wall.
8. 9. The footing unit as claimed in any one of the preceding claims wherein one or both of the side walls include an extension p seee 7 supported adjacent the upper edge of the side wall. S 10. The footing unit as claimed in any one of the L.:3 *a'to preceding claims wherein the extension -peeej has a S'*I configuration to allow it to be self supporting to an upper edge of a respective side wall and this is achieved by having a skirt portion overlying a portion of the side wall below the upper end thereof. 1 11. A footing unit substantially as hereinbefore described with reference to the accompanying drawings. DATED this Fourteenth day oi October, 1992. BESSER PIONEER PTY LTD by their Patent Attorneys CULLEN CO. 13 ABSTRACT A footing unit for use with a poured concrete slab is provided. The footing unit has a base wall and a pair of side walls with one side wall being tigher than the other side wall. An outwardly extending shoulder portion is provided adja ant the higher side wall and on to which bricks or blocks can be mortared. Concrete can be poured in and around the footing unit. 9 9 *9 9