GB2103262A

GB2103262A - Paving-slab with drainage holes for allowing growth of grass

Info

Publication number: GB2103262A
Application number: GB08218912A
Authority: GB
Inventors: John Forsythe Mccall
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-06-30
Filing date: 1982-06-30
Publication date: 1983-02-16
Also published as: GB2103262B

Abstract

The paving slab has two major rectangular faces. In the upper face 10 a network of open-topped channels 12 is provided to hold growing medium in which grass can be grown to creep over lands 14 formed by channels 12. Drainage holes 16, 18 are provided through the slab from channels 12. Through some of these holes, locking pins 19 can be driven into the ground to stabilise the slab. <IMAGE>

Description

SPECIFICATION Paving slabs This invention relates to paving slabs/blocks/stones, hereinafter referred to simply as "paving slabs", of the type which are loadbearing and have recessed portions or voids extending downwardly from an upper face, the recessed portions of voids being for holding growing medium in which primarily grass but other creeping vegetation for cover can be grown.

Hereinafter the term "grass" will be used to include other creeping vegetation. Such paving slabs have been provided heretofore and when laid, over an area of ground, are for use in all weathers for supporting self-propelled or manually-propelled vehicles when parked thereon or driven thereacross without the ground subsiding or becoming uneven through that use.

After a period of time, the grass creeps over the slabs to give the appearance of a grassed area: a more pleasing appearance than simply an area of the material from which the slabs are formed. A disadvantage of existing paving slabs is that, when laid, the growing areas of the slabs consolidate to a level beiow top faces of the slabs thereby forming islands, for example of concrete, which protude above the level of the grass and causes an uneven surface on which pedestrians can stumble, and free-movement of wheels of perambulators, baby carriages, invalid chairs or bicycles is hindered.

It is an object of the present invention to obviate or mitigate this disadvantage by providing a paving slab in which the growing areas have been minimised conductive to maximised cover creeping potential of the grass growing therein.

According to the present invention, a paving slab has two major faces in one of which a network of open-topped channels to receive growing medium are provided with drainage holes extending through to the other face being provided in said channels.

Preferably, the slab is rectangular and the network of channels is symmetrical about both transverse and longitudinal median axes and is formed from two series of equi-spaced parallel channels angularly extending between opposite lateral sides of the slab, the two series being mirror images of each other about said median axes.

Preferably also, the drainage holes are provided at the intersections of the channels and are in the form of bores.

Alternatively, the drainage holes are provided at certain elongate parts of the channels and are in the form of slots.

Preferably further, a plurality of similarlyshaped recesses are provided in the other face.

The recesses are arranged in two series.

Preferably further, each side of a slab has lugs extending outwardly therefrom whereby on a plurality of slabs being laid in juxtaposed positions, lugs of adjacent sides of two slabs are positioned to abut against each other and therefore spaced the said sides apart a determined distance to create a further channel for holding growing medium.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figs. 1 and 2 are top and underneath plan views respectively of a paving slab according to the first embodiment of the present invention; Figs. 3 and 4 are top and underneath plan views respectively of a paving slab according to the second embodiment of the present invention; Fig. 5 is a cross-sectional view on the line V-V of Fig. 1; Fig. 6 is a cross-sectional view on the line V1-V1 of Fig. 1; Fig. 7 is a cross-sectional view on the line "Il-Vil of Fig. 1; Fig. 8 is a cross-sectional view on the line VIll-VIll of Fig. 1; Fig. 9 is a cross-sectional view on the line IX-IX of Fig. 1; and Fig. 10 is a cross-sectional view on the line X-X of Fig. 3.

Referring to the drawings, a paving slab of both embodiments has two major faces, one intended to be the upper face 10 and the other the under face 11, both of which are rectangular, particularly square as shown. The upper face 1 0 (Figs. 1 or 3) has a network of open-topped channels 12 provided thereacross, the channels 1 2 being symmetrically arranged about both transverse and longitudinal median axes. The network is formed from two sides of equi-spaced parallel channels 12 angularly extending between opposite lateral sides of the slab, the two series being mirror-images of each other. Diamond or half-diamond shaped lands or islands 14 are formed by the channels 12.

A plurality of similarly-shaped recesses 13 are provided in the under face 11, arranged in two series as shown in Figs. 2 and 4. Each recess 1 3 (Figs. 2, 4, 6 and 7) is of shape complementary to a pyramid having a diamond-shaped base.

Each side of a slab has lugs 1 5 extending outwardly therefrom as shown. The lugs 1 5 are only part of the depth of a slab and are located as an extension of the lower part of the slab.

In the first embodiment, (Figs. 1, 2 and 5) drainage holes 1 6 are provided at the intersections of the channels 11 and are in the form of bores through the rest of the slab to the underface 11. As can be seen from Fig. 2 there are three parallel rows of holes 16, the bores of the flanking rows impringe upon the recesses 13.

A plurality of locking or position-stabilising pins 1 7 are provided of, for example conical shape, to be driven into the ground through two or more drainage holes 1 6 as desired in an inverted attitude to prevent the slab from movement after being laid on prepared level ground.

In the second embodiment (Figs. 3, 4 and 10) drainage holes 1 8 are provided at certain elongate parts of the channels 12 and are in the form of slots through the rest of the slab to the under face 1 As can be seen from Fig. 4, the slots impringe upon the recesses 13. A plurality of locking or stabilizing pins 1 9 are provided having an elongate head and to be driven into the ground through two or more drainage holes 1 8 at one end thereof.

An area of ground is prepared and levelled and a plurality of slabs above-described of either or both embodiments are laid down thereon in juxtaposed positions with the lugs 1 5 of adjacent sides of two slabs abutting against each other to space the said sides apart a determined distance to create a further channel. After the slabs are laid and locking pins driven into the ground, growing medium is filled and compacted into the channels 12, drainage holes 16, 18 and channels formed between adjacent slabs and seeded. Grass grown therein gradually creeps over the diamond lands 14, and forms a cover therefore. The upper face 10 of the lands 14 are flat and the channels 12 are narrow relative thereto.The consolidation of the growing medium in the channels is minimal and the narrowness of the channels is relative to the lands means that the only unevenness possible is that due to the depth of grass on top of the lands not sufficient for pedestrians to stumble over or to cause a bumby ride for a wheeled vehicle.

The drainage holes are provided to remove excess water on top of the slabs to the sub-soil over which the slabs are laid, the bottom of the channels holding a proportion of the water for irrigation of the grass.

The recesses 13 can serve as keying means if the slabs are laid flat and no locking pins are to be used. Also condensation from the ground will condense on the walls and run theredown to the drainage holes and, in particularly dry weather, may serve to irrigate the root formation of the grass.

Slabs may be used to enhance or stabilise banks where the slabs are laid at angles on soil and sand bed or vertically as wall decoration both internally or externally. The locking pins are used to secure the slabs in position.

Claims

1. A paving slab having two major faces in one of which a network of open-topped channels to receive growing medium are provided, and drainage holes extending through to the other face being provided in said channels.

2. A paving slab as claimed in Claim 1, wherein the slab is rectangular and the network of channels is symmetrical about both transverse and longitudinal median axes.

3. A paving slab as claimed in Claim 2, wherein the network is formed from two series of equispaced parallel channels angularly extending between opposite lateral sides of the slab, the two series being mirror images of each other about said median axes.

4. A paving slab as claimed in Claim 1, 2 or 3, wherein the drainage holes are provided at the inter-sections of the channels and are in the form of bores.

5. A paving slab as claimed in Claim 1, 2 or 3, wherein the drainage holes are provided at certain elongate parts of the channels and are in the form of slots.

6. A paving slab as claimed in Claim 1, 2, 3 or 4, wherein a plurality of similarly shaped recesses are provided in the other face.

7. A paving slab as claimed in Claim 6, wherein the recesses are arranged in two series.

8. A paving slab as claimed in any one of the preceding Claims, wherein each side of the slab has lugs extending outwardly therefrom whereby on a plurality of slabs being laid in juxtaposed positions, lugs of adjacent sides of two slabs are positioned to abut against sides of two slabs are posited to abut against each other and therefore spaced the said sides apart a determined distance to create a further channel for holding growing medium.

9. A paving slab as claimed in any one of the preceding claims, wherein two or more locking pins are provided to be driven into the ground through drainage holes to stabilise the slab

10. A paving slab substantially as hereinbefore described with reference to Figs. 1, 2, 5, 6, 7, 8 or 9 of the accompanying drawings.

11. A paving slab substantially as hereinbefore described with reference of Figs. 3, 4, 6, 7, 8, 9 or 10 of the accompanying drawings.