Method of Laying a Foundation

Abstract

A method for laying a foundation that includes the following steps (a) digging a foundation trench (2), (b) pouring concrete (4) into the foundation trench to a first level (6); (c) allowing the concrete to partially cure to a predetermined state; (d) pressing blocks (10) into the concrete to a desired level equal to the desired finish height (11) of the foundation; (e) filling the blocks with sufficient concrete (13) to complete the foundation; where the predetermined state of the partially cured concrete is such that the partially cured concrete allows the blocks to be pressed into the surface of the concrete without risk of sinking further.

Description

FIELD OF THE INVENTION

The present invention relates to a method of laying a foundation for a building, more specifically a method for laying a foundation of a residential dwelling, garage or smaller commercial/industrial building.

BACKGROUND

Foundations for smaller buildings are traditionally laid by a method that includes the following steps:

• • (i) digging the foundation trench;
  • (ii) boxing up the foundation;
  • (iii) installing the reinforcing;
  • (iv) pouring the foundation; and
  • (v) removing the boxing, dump or recover boxing.

This method is labour intensive, requires boxing and requires 2 to 3 days to lay a foundation. The boxing needs to be removed, cleaned and recycled or dumped after use, adding to the costs. With the variability of the timber used for boxing the resultant foundation can also need remedial work to correct faults from warped, badly installed or damaged boxing; this further adds cost and time to the process.

A second method, used where the cost of concrete is high, includes the following steps:

• • (ia) digging the foundation trench;
  • (iia) pouring the foundation;
  • (iiia) pouring the foundation, to a level below the top of the trench;
  • (iva) allowing the foundation to cure until rigid;
  • (va) laying blocks on top of concrete; and
  • (via) filling block cavities with concrete to complete the foundation.

This second method removes the cost of the boxing and inherent cleanup, disposal and recycling of boxing steps. This method also dispenses with the labour costs and time associated with the boxing. It does however add the cost of a sub-contractor to lay the blocks, which can add substantially to the cost of the foundation and depends on the availability of that sub-contractor. This second method adds the cost of mortar to lay the blocks and can take about two days due to the requirement for a block layer.

With the cost of labour being one major cost associated with the laying of a foundation and increasing time pressures being placed on building projects there is a need for an improved method of laying a foundation that reduces the time taken to lay a foundation. This improved method ideally needs to avoid boxing and the associated problems, and if possible reduce or remove the need for additional sub-contractors. However any improved method must not compromise the quality or longevity of the final foundation.

OBJECT OF THE INVENTION

It is therefore an object of this invention to provide a method of laying a foundation that can reduce the time taken and overall cost of the foundation when compared to traditional methods.

It is a further object of the invention to reduce the cost of laying a foundation over traditionally employed methods, without compromising the integrity of the foundation.

DISCLOSURE OF THE INVENTION

The present invention provides a method for laying a foundation that includes the following steps:

• • (a) digging a foundation trench;
  • (b) pouring concrete into the foundation trench to a first level;
  • (c) allowing the concrete to partially cure to a predetermined state;
  • (d) pressing blocks into the concrete to a desired level equal to the desired finish height of the foundation;
  • (e) filling the blocks with sufficient concrete to complete the foundation;
    where the predetermined state of the partially cured concrete is such that the partially cured concrete allows the blocks to be pressed into the surface of the concrete without risk of sinking further.

Preferably before step (b) reinforcing is installed.

Preferably the first level and/or final block level are set by string level, optical level or laser level. It is highly preferred that the first level and/or final block level are laser aligned and/or laser screeded.

Preferably the blocks are pressed into the concrete to a depth of between 1 mm and 20 mm, an optimum depth being approximately 5 mm.

Subsequent building steps can be commenced during the laying of the blocks, for example pouring the shingle fill for the floor can be commenced.

The present invention also includes a foundation prepared by the method described above.

DESCRIPTION OF THE DRAWINGS

By way of example only, a preferred embodiment of the present invention is described in detail with reference to the accompanying drawings, in which:—

FIG. 1 shows a flowchart of the method;

FIG. 2 shows a cross sectional view along the foundation trench of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings the present method for laying a foundation (1) includes a first step (A) where a foundation trench (2) is formed in the standard way, this is followed by a second step (B) which involves the installation into the foundation trench (2) of initial reinforcing (3) which is part of the complete reinforcing required to meet the local standards.

In the third step (C) concrete, of standard grade, is poured into the foundation trench (2) as a concrete platform (4). The concrete platform is laser screeded, i.e. the surface (5) of the concrete platform (4) is precisely adjusted to the required level (6) using a laser level of standard design. This required level (6) allows one or more concrete blocks (10) to be inserted into the concrete platform (4) to a depth of between 0 mm and 20 mm in a fifth step (E).

In the fourth step (D) the concrete platform (4) is allowed to partially cure; this partial cure is sufficient to maintain the position, without sinking, of the or each concrete block (10) inserted into the concrete platform (4) in the fifth step (E) in position without requiring excessive force. Excessive force in this context is a force that would cause the concrete platform (4) to be permanently damaged.

In the fifth step (E) the or each concrete block (10) is inserted into the surface (5) of the partially cured concrete platform (4), and the height of a top (11) edge of the or each concrete block (10) is adjusted to the required height using a laser or string level. The or each concrete block (10) is butted up against each adjacent concrete block (10).

The sixth step (F) includes the installation of final reinforcing (12) which completes the complete reinforcing. The seventh step (G) includes the filling of the or each concrete block (10) with a concrete fill (13) to complete the foundation.

As the seventh step (G) is being completed it is possible to start pouring the shingle required for the floor slab, and in fact, if the correct grades of concrete are selected, the floor laying stages could be commenced the same day as completing the foundation.

The present method therefore does not require the use of boxing and therefore the time, material and costs associated with boxing are avoided. In addition there is no requirement for a sub-contracting block layer to be involved, thus the cost and time associated with this is avoided. These savings are achieved without compromising the longevity or quality of the foundation.

Claims

1. A method for laying a foundation that includes the following steps: where the predetermined state of the partially cured concrete is such that the partially cured concrete allows the blocks to be pressed into the surface of the concrete without risk of sinking further.

(a) digging a foundation trench;

(b) pouring concrete into the foundation trench to a first level;

(c) allowing the concrete to partially cure to a predetermined state;

(d) pressing blocks into the concrete to a desired level equal to the desired finish height of the foundation;

(e) filling the blocks with sufficient concrete to complete the foundation;

2. The method as claimed in claim 1 characterised in that, before step (b) reinforcing is installed.

3. The method as claimed in claim 1 wherein the first level and/or final block level is set by one or more methods selected from the list consisting of string level, optical level and laser level.

4. The method as claimed in claim 1 wherein the first level is laser aligned and/or laser screeded.

5. The method as claimed in claim 1 wherein the final block level is laser aligned and/or laser screeded.

6. The method as claimed in claim 1 characterised in that, the blocks are pressed into the concrete to a depth of between 1 mm and 20 mm.

7. The method as claimed in claim 6 characterised in that, the blocks are pressed into the concrete to a depth of approximately 5 mm.

8. The method as claimed in claim 1 wherein one or more subsequent building step is commenced during the laying of the blocks.

9. The method as claimed in claim 8 wherein the one or more subsequent building step includes pouring a shingle fill for a floor.

10. A foundation prepared by the method as claimed in claim 1.

11. (canceled)

12. (canceled)