GB2354534A

GB2354534A - Precast flooring supported on horizontally spaced joists

Info

Publication number: GB2354534A
Application number: GB0014737A
Authority: GB
Inventors: John Joseph Carroll
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-19
Filing date: 2000-06-19
Publication date: 2001-03-28
Anticipated expiration: 2020-06-19
Also published as: GB9914294D0; GB0014737D0; GB2354534B

Abstract

A method of constructing a floor including the steps of casting a slab in a mould using a sand and cement mixture, and arranging the slab on horizontally spaced apart joists. Preferably the slab has a polymer coating on an upper side and incorporates a reinforcing medium and insulation material. Any voids, such as between the supports, beneath the slabs or between adjacent slabs may be filled with grout. The joists are preferably elongate and are provided with ducts and openings in an upper surface such that grout may be supplied to the gaps between the slabs. Also disclosed is a method of casting a slab comprising pouring a cement mixture into a mould, modifying the mould and applying a liquid polymer mixture onto the surface of the cement mixture.

Description

2354534 FLOORING This invention relates to flooring construction, to a

novel pre-formed flooring slab, and to methods of laying flooring using pre-formed flooring slabs.

The invention stems from work to simplify the on-site laying of flooring which traditionally comprises a sereed laid in situ.

When a screed floor has to be laid which is capable of being used a relatively short time thereafter it is necessary to employ a fast-setting composition which considerably increases the cost of the floor.

According to one aspect of the present invention a method of constructing a floor comprises mixing a sand and cement mixture, which mixture may comprise an aggregate, and casting a flooring slab from said mixture in a mould, the slab having a substantial width to thickness ratio, transporting the flooring slab to a site where the floor is to be constructed, and arranging the slab on horizontally spaced-apart supports to form the floor.

Preferably the slab has a width to thickness ratio of at least fifty.

When a solid floor is required to have a smooth durable surface it is common practice to lay a polymer topping on top of the main flooring material. A typical polymer coating is available as Ronacrete TM from Ronacrete Limited. The polymer is applied in liquid form on the surface of the concrete floor and sets to form a smooth finish.

2 According to a preferred feature of the present invention, the cast flooring slab is coated on one side with a polymer coating, whereby the pre-formed flooring slab delivered to the site already carries the polymer coating, on the side that is uppermost in use.

The void defined between the supports and beneath the slabs may be filled with grout under pressure, if desired, and it should be noted that the upper surface of the slab "Will still be usable whilst the grout is setting.

The flooring slabs are typically of thickness in the range 70 mm to 100 mm and are typically of width 3 meters. However, the slabs may have a thickness as small as 20 mm or 25 mm, for example.

The slabs are preferably laid with a small gap between adjacent edges, and the gap is then filled with a suitable grout.

The slabs are preferably laid on joists or on other horizontally spacedapart slab support members. The joists may be of concrete, metal or wood.

When the slabs are laid on wooden joists they may be secured in position with screws driven into the wood.

When the void between the supports is to be filled with grout, fixing for the slabs may be arranged to extend into the void for entrapment by the grout so as to secure the slabs once the grout has set.

The joists may be provided with ducts and with openings in their upper surfaces, the ducts being employed to supply grout under pressure through said openings to fill the gaps between the slabs.

3 The duct is preferably supplied with grout through a suitable fitting, preferably located at one end of the joist.

The supports may be local supports which engage with a corner region of the slabs, such as concrete pillars.

The slab may incorporate a reinforcing medium such as fibres or flakes, or steel rod or wire reinforcement. When a fibre is employed the fibre is preferably a suitable glass fibre.

According to a second aspect of the invention a method of casting a slab, which is suitable for use in the method of the first aspect, comprises pouring a cement mixture into a mould defined by a mould base and upstanding mould side strips, tamping the cement mixture down to the level of the top of the side strips, raising the side strips by a predetermined amount corresponding to a thickness of a polymer layer to be applied, applying a liquid polymer mixture on the surface of the cement mixture, and then allowing the materials to set at least to a condition in which the slab can be removed from the mould.

The upper surface of the slabs may be provided with mosaic or other decorative finish, such as a parquet finish, which can be applied during moulding of the slab or subsequently.

The rear side of the slabs may be provided with an insulation layer, such as a layer of expanded polystyrene, which may be positioned in the mould prior to casting of the slab, or which may be applied to the cast slab. In the case of a relatively thick slab, an insulation layer may be provided at an intermediate depth of the slab by spreading a layer of sand/cement mixture in the mould, inserting the insulation layer and then 4 spreading further sand/cement mixture on top of the insulation layer in the mould.

The sand/cement mixture may incorporate a bulk density reducer such as Vermiculite or Lytag' material.

The slabs may be cast with internal ducts to accommodate wires or pipes, for example to provide underfloor heating.

Where wires or pipes have been inserted into the laid slabs, insulation or grout may be forced into any voids remaining in the ducts.

Claims

1. A method of constructing a floor comprising mixing a sand and cement mixture, which mixture may comprising an aggregate, and casting a flooring slab from said mixture in a mould, the slab having a substantial width to thickness ratio, transporting the flooring slab to a site where the floor is to be constructed, and arranging the slab on horizontally spaced-apart supports to form the floor.

2. A method as claimed in claim 1 in which the slab has a width to thickness ratio of at least fifty.

3. A method as claimed in claim 1 or claim 2 in which the cast flooring slab is coated on one side with a polymer coating, whereby the pre-formed flooring slab delivered to the site already carries the polymer coating, on the side that is uppermost in use.

4. A method as claimed in any of the preceding claims in which the void defined between the supports and beneath the slabs is filled with grout under pressure.

5. A method as claimed in any of the preceding claims in which the flooring slabs are of thickness in the range 70 mm to 100 mm.

6. A method as claimed in any of the preceding claims in which the slabs are laid with a small gap between adjacent edges, and the gap is then filled with a suitable grout.

7. A method as claimed in any of the preceding claims in which the slabs are laid on elongate horizontally spaced-apart slab support members.

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8. A method as claimed in claim 7 in which the slabs are laid on wooden joists and are secured in position with screws driven into the wood.

9. A method as claimed in claim 7 in which the support members are in the form of joists provided with ducts and with openings in their upper surfaces, the ducts being employed to supply grout under pressure through said openings to fill the gaps between the slabs.

10. A method as claimed in any one of claims 1 to 6 in which the supports are local supports which engage with a corner region of the slabs.

11. A method as claimed in any of the preceding claims comprising incorporating a reinforcing medium such as fibres or flakes, or steel rod or wire reinforcement into the material of the slab.

12. A method as claimed in claim 3 or any of claims 4 to 11 each as appended to claim 3 in which the casting of the slab, which is suitable for use in the method of the first aspect, comprises pouring a cement mixture into a mould defined by a mould base and upstanding mould side strips, tamping the cement mixture down to the level of the top of the side strips, raising the side strips by a predetermined amount corresponding to a thickness of a polymer layer to be applied, applying a liquid polymer mixture on the surface of the cement mixture, and then allowing the materials to set at least to a condition in which the slab can be removed from the mould.

13. A method as claimed in any of the preceding claims comprising positioning a layer of insulation material in the mould prior to casting of the slab.

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14. A method as claimed in any one of claims 1 to 12 in which an insulation layer is provided at an intermediate depth of the slab by spreading a layer of sand/cement mixture in the mould, inserting the insulation layer into the mould, and then spreading further sand/cement 5 mixture on top of the insulation layer in the mould.

15. A method of constructing a floor substantially as described herein.

16. A method of casting a slab comprising pouring a cement mixture into a mould defined by a mould base and upstanding mould side strips, tamping the cement mixture down to the level of the top of the side strips, raising the side strips by a predetermined amount corresponding to a thickness of a polymer layer to be applied, applying a liquid polymer mixture on the surface of the cement mixture, and then allowing the materials to set at least to a condition in which the slab can be removed from the mould.